JP2020018130A - Dynamo-electric machine - Google Patents

Abstract

To provide a dynamo-electric machine capable of stopping rotation of a magnet suitably.SOLUTION: A dynamo-electric machine includes a rotor 40 having a magnet unit 42, and a cylinder part 43, and a stator 50. The magnet unit 42 has a magnet 2001 oriented so that an easy axis of magnetization become parallel with the d-axis compared with the q-axis side, on the d-axis side, and a magnet path is formed along the easy axis of magnetization. The cylinder part 43 has a protrusion 2002 protruding to the magnet unit side in the radial direction. At a part of the magnet unit 42 on the anti-stator side, a recess 2003 opening to the anti-stator side, and engaging with the protrusion 2002 in the hoop direction is provided. The recess 2003 is provided closer to the d-axis side than the q-axis side in the hoop direction.SELECTED DRAWING: Figure 23

Description

  The disclosure in this specification relates to a rotating electric machine.

  DESCRIPTION OF RELATED ART Conventionally, as described in patent document 1, the rotating electric machine applied for household appliances, industrial machines, amusement machines, agricultural construction machines, and automobiles is known, for example. Generally, a so-called slot, which is a winding accommodating portion partitioned by teeth, is formed in a stator core (that is, an iron core), and a conductor such as a copper wire or an aluminum wire is accommodated in the slot, thereby forming a stator winding. Lines are configured. On the other hand, a slotless motor in which the teeth of the stator are eliminated has been proposed (for example, Patent Document 1). Further, Patent Document 1 proposes a motor having an outer rotor structure in which a rotor having a magnet is arranged radially outside a stator.

JP-A-6-70522

  By the way, in the rotating electrical machine, it is necessary to appropriately stop the rotation so that the magnet does not shift in the circumferential direction when the rotor rotates.

  The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a rotating electric machine capable of suitably stopping rotation of a magnet.

  The embodiments disclosed in this specification employ different technical means to achieve their respective objects. The objects, features, and advantages disclosed in this specification will become more apparent with reference to the following detailed description and the accompanying drawings.

Means 1
A field element having a magnet portion including a plurality of magnetic poles having alternating polarities in a circumferential direction, and a cylindrical magnet holding portion fixed in a state where the magnet portions are stacked in a radial direction, and a multiphase magnetic field element. An armature having an armature winding, comprising: a rotating electric machine having one of the field element and the armature as a rotor,
The magnet unit is oriented such that the direction of the easy axis of magnetization is parallel to the d-axis on the d-axis side, which is the center of the magnetic pole, compared to the q-axis side, which is the boundary of the magnetic pole, and the magnets are aligned along the easy axis of magnetization. Having a magnet in which a magnetic path is formed,
The magnet holding portion is disposed closer to the armature side than the magnet portion in the radial direction, and has a protrusion protruding toward the magnet portion in the radial direction,
In the radial direction, a portion of the magnet portion on the side opposite to the armature is provided with a concave portion that opens on the opposite side of the armature and engages with the convex portion in the circumferential direction.
The concave portion is provided on the d-axis side rather than the q-axis side in the circumferential direction.

  On the d-axis side which is the center of the magnetic pole, the direction of the easy axis is oriented so as to be parallel to the d-axis as compared with the q-axis side which is the magnetic pole boundary, and a magnet magnetic path is formed along the easy axis. The magnet is used for the magnet part. When this magnet is composed of a plurality of magnets, in order to obtain a magnetic flux density distribution close to a sine wave shape and to increase the magnetic flux density in the d-axis, it is desirable to minimize the gap between magnets adjacent in the circumferential direction. . However, if the gap between the adjacent magnets is made small, the engagement portion arranged in the gap becomes thin, and it becomes impossible to suitably perform the rotation stop.

  Further, when the magnet is a single magnet formed in an annular shape, the magnetic flux density distribution is close to a sine wave shape, and the magnetic flux density on the d-axis can be increased. You will not be able to do it.

  By the way, in the portion near the d-axis of the magnet, the portion on the side opposite to the armature is a portion where the magnet magnetic path is likely to be short and demagnetized easily. That is, even if this portion is deleted, the influence on the magnetic flux density generated from the d-axis is small.

  Therefore, in the portion of the magnet portion on the side opposite to the armature and on the side closer to the d-axis than the q-axis, a concave portion that opens on the side opposite to the armature, that is, on the side of the magnet holding portion, is provided. Provided a convex portion which engages with the concave portion in the circumferential direction. As described above, since the portion where the concave portion is provided is a portion that is easily demagnetized, even if the concave portion is provided, there is little effect on the magnetic flux density, and the thickness is such that the rotation can be suitably stopped. As described above, it is possible to secure the size of the concave portion in the circumferential direction. Thereby, it is possible to suitably perform the rotation stop in the circumferential direction. In addition, as described above, since the concave portion is provided in a portion that is easily demagnetized, the magnetic flux density distribution is close to a sine wave shape, and the magnetic flux density on the d-axis is increased, and the rotation of the magnet portion is preferably stopped. Can be.

The means 2 is the same as the means 1,
The field element includes an end plate that fixes the magnet holding unit in the axial direction,
In the magnet holding portion, a hole is provided along the axial direction, and a fastener projecting in the axial direction from the end plate is inserted into the hole of the magnet holding portion,
The hole is provided at a position overlapping the protrusion in the circumferential direction.

  By inserting the fastening portion from the end plate into the hole provided in the magnet holding portion, even if the magnet holding portion and the end plate are configured separately, the magnet holding portion is not rotated when the rotor rotates. Can be restricted from rotating in the circumferential direction. And the hole part of the magnet holding part was provided in the position overlapped with the convex part in the circumferential direction. Thereby, even when the hole is provided in the magnet holding portion, the thickness in the radial direction is suppressed from being reduced as compared with the place where the hole is not provided, and the magnet holding portion is provided. A decrease in strength can be suppressed. For this reason, it is possible to suitably perform the rotation stop.

  When the magnet holding portion is made of a soft magnetic material and functions as a back yoke of the magnet portion, a hole is provided, and when the thickness of the magnet holding portion in the radial direction is reduced, the portion is magnetically saturated and magnet leakage is caused. Can occur. Therefore, by providing the hole at a position overlapping the protrusion in the circumferential direction, it is possible to suppress the thickness of the magnet holding portion in the radial direction from becoming thinner, and to suppress magnetic flux leakage.

  The means 3 is such that in the means 2, at least a part of the hole is provided at a position overlapping the convex portion in the radial direction.

  This makes it possible to reduce the thickness of the magnet holder in the radial direction.

  In the means 4, the size of the protrusion in the radial direction in the means 2 or 3 is larger than the size of the hole.

  Thereby, the thickness in the radial direction in the portion where the hole is provided in the circumferential direction can be made equal to or greater than the thickness in the portion where the hole is not provided, and Strength can be maintained.

  In the case where the magnet holding portion is made of a soft magnetic material and functions as a back yoke of the magnet portion, a hole is provided to reduce the thickness (thickness excluding the hole) of the magnet holding portion in the radial direction. Then, there is a possibility that magnetic saturation occurs in the portion and magnet leakage occurs. Therefore, by making the size of the protrusion larger than the size of the hole, the radial thickness (thickness excluding the hole) of the magnet holding portion can be maintained, and magnetic flux leakage can be prevented.

Means 5 is the cylindrical part, in any one of means 1 to 4, wherein the field element is fixed in a state where the magnet holding portions are stacked in a radial direction on a side opposite to the armature side of the magnet holding portions. Has,
The magnet holding portion has an engaging portion that is engaged in a circumferential direction with an engaged portion provided on the cylindrical portion,
The engaging portion is provided at a different position in the circumferential direction with respect to the convex portion.

  Since the engaging portion is provided at a different position in the circumferential direction with respect to the convex portion of the magnet holding portion, the stress from the magnet portion and the stress from the cylindrical portion are concentrated at the same position in the circumferential direction. It can be prevented from being added. That is, the stress from the magnet part and the stress from the cylindrical part can be dispersed. For this reason, it is possible to suppress deformation or the like of the magnet holding portion.

Means 6 is any one of means 1 to 5, wherein a plurality of the magnets are provided and are arranged side by side in a circumferential direction;
The magnet holding portion radially connects an inner wall portion arranged inside the magnet portion, an outer wall portion arranged outside the magnet portion, and the inner wall portion and the outer wall portion. And a side wall provided along the radial direction so as to partition between the magnets adjacent in the circumferential direction,
The side wall portion is provided at a position overlapping the convex portion in the circumferential direction, and the width of the side wall portion in the circumferential direction is smaller than the width of the convex portion in the circumferential direction. Have been.

  Since the rotation can be stopped by the convex portion, the rotation can be suitably stopped even if the strength is weakened by thinning the side wall portion. Further, by reducing the thickness of the side wall portion, the gap between the magnets can be reduced to obtain a magnetic flux density distribution close to a sine wave shape, and the magnetic flux density on the d-axis can be improved. In addition, since the inside and outside are surrounded by the inner wall and the outer wall of the magnet holding portion in the radial direction, it is possible to prevent the magnet from dropping in the radial direction.

  Means 7 is any one of means 1 to 6, wherein the magnet portion has a specific coercive force of 400 [kA / m] or more and a residual magnetic flux density of 1.0 [T] or more.

  Thereby, torque can be improved.

FIG. FIG. 4 is a longitudinal sectional view of the rotating electric machine. FIG. 3 is a sectional view taken along line III-III of FIG. 2. Sectional drawing which expands and shows a part of FIG. FIG. FIG. 3 is an exploded view of the inverter unit. FIG. 4 is a torque diagram showing a relationship between an ampere-turn of a stator winding and a torque density. FIG. 4 is a cross-sectional view of the rotor and the stator. The figure which expands and shows a part of FIG. FIG. The longitudinal section of a stator. The perspective view of a stator winding. FIG. 2 is a perspective view showing a configuration of a conductive wire. The schematic diagram which shows the structure of a strand. The figure which shows the form of each lead in the n-th layer. FIG. 6 is a side view showing the respective conductors of the n-th layer and the (n + 1) -th layer. The figure which shows the relationship between an electric angle and magnetic flux density about the magnet of embodiment. The figure which shows the relationship between an electric angle and a magnetic flux density about the magnet of a comparative example. The electric circuit diagram of the control system of a rotating electric machine. FIG. 4 is a functional block diagram showing current feedback control processing by the control device. FIG. 4 is a functional block diagram illustrating a torque feedback control process performed by the control device. FIG. 6 is a cross-sectional view of a rotor and a stator according to a second embodiment. The figure which expands and shows a part of FIG. FIG. 13 is a cross-sectional view of the rotor and the stator according to the third embodiment. The figure which expands and shows a part of FIG. The figure which shows the flow of the magnetic flux in a magnet unit concretely. Sectional drawing of the stator in the modification 1. Sectional drawing of the stator in the modification 1. Sectional drawing of the stator in the modification 2. Sectional drawing of the stator in the modification 3. Sectional drawing of the stator in the modification 4. FIG. 19 is a cross-sectional view of a rotor and a stator according to a seventh modification. FIG. 21 is a functional block diagram showing a part of the processing of the operation signal generation unit in a modification 8. 9 is a flowchart illustrating a procedure of a carrier frequency change process. The figure which shows the connection form of each conductor which comprises a conductor group in the modification 9. The figure which shows the structure by which four pairs of conducting wires are laminated | stacked in the modification 9. FIG. 21 is a cross-sectional view of an inner rotor type rotor and a stator in a modification 10; The figure which expands and shows a part of FIG. FIG. 3 is a longitudinal sectional view of an inner rotor type rotating electric machine. FIG. 2 is a longitudinal sectional view illustrating a schematic configuration of an inner rotor type rotating electric machine. The figure which shows the structure of the rotary electric machine of an inner rotor structure in the modification 11. The figure which shows the structure of the rotary electric machine of an inner rotor structure in the modification 11. The figure which shows the structure of the rotary electric machine of a rotary armature type in the modification 12. FIG. 21 is a sectional view showing a configuration of a conductive wire according to a modification 14; The figure which shows the relationship between reluctance torque, magnet torque, and DM. The figure which shows a tooth. The longitudinal section of the rotor in another example. FIG. 9 is a cross-sectional view of a rotor and a stator according to another example. FIG. 9 is an enlarged cross-sectional view of a rotor and a stator in another example. FIG. 9 is a cross-sectional view of a rotor in another example. FIG. 7 is an enlarged cross-sectional view of a rotor and a stator in another example. FIG. 7 is an enlarged cross-sectional view of a rotor and a stator in another example. FIG. 9 is an enlarged cross-sectional view of a rotor and a stator in another example. FIG. 9 is an enlarged cross-sectional view of a rotor and a stator in another example.

  A plurality of embodiments will be described with reference to the drawings. In embodiments, functionally and / or structurally corresponding parts and / or associated parts may be provided with the same reference signs or reference signs that differ by more than a hundred places. For corresponding parts and / or associated parts, the description of the other embodiments can be referred to.

  The rotating electric machine according to the present embodiment is used, for example, as a vehicle power source. However, rotating electric machines can be widely used for industrial use, vehicles, home appliances, OA equipment, gaming machines, and the like. In the following embodiments, parts that are the same or equivalent to each other are given the same reference numerals in the drawings, and the description of the parts with the same reference numerals is used.

(1st Embodiment)
The rotating electric machine 10 according to the present embodiment is a synchronous polyphase AC motor and has an outer rotor structure (eternal rotation structure). The outline of the rotating electric machine 10 is shown in FIGS. 1 is a vertical cross-sectional perspective view of the rotary electric machine 10, FIG. 2 is a vertical cross-sectional view of the rotary electric machine 10 in a direction along a rotation axis 11, and FIG. 3 is a cross-sectional view of the rotary electric machine 10 (a cross-sectional view taken along line III-III in FIG. 2). FIG. 4 is an enlarged cross-sectional view illustrating a part of FIG. 3. It is. In FIG. 3, hatching indicating a cut surface is omitted except for the rotation shaft 11 for convenience of illustration. In the following description, the direction in which the rotating shaft 11 extends is defined as the axial direction, the direction radially extending from the center of the rotating shaft 11 is defined as the radial direction, and the direction extending circumferentially around the rotating shaft 11 is defined as the circumferential direction.

  The rotating electric machine 10 is roughly divided into a bearing unit 20, a housing 30, a rotor 40, a stator 50, and an inverter unit 60. Each of these members is arranged coaxially with the rotating shaft 11 and assembled in a predetermined order in the axial direction to form the rotating electric machine 10. The rotating electric machine 10 of the present embodiment has a configuration having a rotor 40 as a “field element” and a stator 50 as an “armature”, and is embodied as a rotating field type rotating electric machine. It has become something.

  The bearing unit 20 has two bearings 21 and 22 that are arranged apart from each other in the axial direction, and a holding member 23 that holds the bearings 21 and 22. The bearings 21 and 22 are, for example, radial ball bearings, each of which has an outer ring 25, an inner ring 26, and a plurality of balls 27 arranged between the outer ring 25 and the inner ring 26. The holding member 23 has a cylindrical shape, and bearings 21 and 22 are attached to the inside in the radial direction. The rotating shaft 11 and the rotor 40 are rotatably supported inside the bearings 21 and 22 in the radial direction. The bearings 21 and 22 constitute a set of bearings that rotatably support the rotating shaft 11.

  In each of the bearings 21 and 22, the ball 27 is held by a retainer (not shown), and the pitch between the balls is maintained in that state. The bearings 21 and 22 have sealing members at upper and lower portions in the axial direction of the retainer, and are filled with non-conductive grease (for example, non-conductive urea grease). Further, the position of the inner ring 26 is mechanically held by a spacer, and a constant-pressure preload that is vertically convex from the inside is applied.

  The housing 30 has a cylindrical peripheral wall 31. The peripheral wall 31 has a first end and a second end that face each other in the axial direction. The peripheral wall 31 has an end face 32 at a first end and an opening 33 at a second end. The opening 33 is open at the entire second end. A circular hole 34 is formed in the center of the end face 32, and the bearing unit 20 is fixed to the end face 32 by a fixing tool such as a screw or a rivet while being inserted through the hole 34. A hollow cylindrical rotor 40 and a hollow cylindrical stator 50 are accommodated in the housing 30, that is, in an internal space defined by the peripheral wall 31 and the end surface 32. In the present embodiment, the rotating electric machine 10 is of an outer rotor type, and a stator 50 is disposed inside a housing 30 in a radial direction of a cylindrical rotor 40. The rotor 40 is cantilevered by the rotating shaft 11 on the end face 32 side in the axial direction.

  The rotor 40 has a magnet holder 41 formed in a hollow cylindrical shape, and an annular magnet unit 42 provided radially inside the magnet holder 41. The magnet holder 41 has a substantially cup shape and has a function as a magnet holding member. The magnet holder 41 includes a cylindrical portion 43 having a cylindrical shape, a fixed portion (attachment) 44 also having a cylindrical shape and a smaller diameter than the cylindrical portion 43, and an intermediate portion serving as a portion connecting the cylindrical portion 43 and the fixed portion 44. 45. The magnet unit 42 is mounted on the inner peripheral surface of the cylindrical portion 43.

  The magnet holder 41 is made of a cold-rolled steel plate (SPCC) having sufficient mechanical strength, forging steel, carbon fiber reinforced plastic (CFRP), or the like.

  The rotating shaft 11 is inserted into the through-hole 44a of the fixing portion 44. The fixed part 44 is fixed to the rotating shaft 11 arranged in the through hole 44a. That is, the magnet holder 41 is fixed to the rotating shaft 11 by the fixing unit 44. The fixing portion 44 may be fixed to the rotating shaft 11 by spline connection or key connection using irregularities, welding, caulking, or the like. Thereby, the rotor 40 rotates integrally with the rotating shaft 11.

  The bearings 21 and 22 of the bearing unit 20 are mounted radially outside the fixing portion 44. Since the bearing unit 20 is fixed to the end face 32 of the housing 30 as described above, the rotating shaft 11 and the rotor 40 are rotatably supported by the housing 30. Thereby, the rotor 40 is rotatable in the housing 30.

  The rotor 40 is provided with a fixing portion 44 only at one of two axially opposed ends thereof, whereby the rotor 40 is cantilevered on the rotating shaft 11. Here, the fixed portion 44 of the rotor 40 is rotatably supported at two different positions in the axial direction by the bearings 21 and 22 of the bearing unit 20. That is, the rotor 40 is rotatably supported at one of two axially opposed ends of the magnet holder 41 by the two bearings 21 and 22 spaced apart in the axial direction. Therefore, even when the rotor 40 has a structure in which the rotor 40 is cantilevered by the rotating shaft 11, stable rotation of the rotor 40 is realized. In this case, the rotor 40 is supported by the bearings 21 and 22 at a position shifted to one side with respect to the axial center position of the rotor 40.

  Further, in the bearing unit 20, a gap between the outer ring 25 and the inner ring 26 and the ball 27 is formed between the bearing 22 near the center of the rotor 40 (lower side in the figure) and the bearing 21 on the opposite side (upper side in the figure). The dimensions are different, for example, the bearing 22 near the center of the rotor 40 has a larger gap size than the bearing 21 on the opposite side. In this case, on the side near the center of the rotor 40, even if vibration of the rotor 40 or vibration due to imbalance due to component tolerance acts on the bearing unit 20, the influence of the vibration or vibration is favorably absorbed. You. Specifically, the play size (gap size) is increased by the preload in the bearing 22 near the center of the rotor 40 (the lower side in the figure), so that the vibration generated in the cantilever structure is absorbed by the play portion. You. The preload may be either a fixed position preload or a constant pressure preload. In the case of the fixed position preload, the outer races 25 of the bearing 21 and the bearing 22 are both joined to the holding member 23 by a method such as press fitting or bonding. The inner races 26 of the bearing 21 and the bearing 22 are both joined to the rotating shaft 11 by a method such as press fitting or bonding. Here, by arranging the outer ring 25 of the bearing 21 at a different position in the axial direction with respect to the inner ring 26 of the bearing 21, a preload can be generated. Preload can also be generated by arranging the outer ring 25 of the bearing 22 at a different position in the axial direction with respect to the inner ring 26 of the bearing 22.

  When a constant-pressure preload is employed, a preload spring, for example, a wave washer 24, is provided in the axial direction so that a preload is generated from the region between the bearing 22 and the bearing 21 toward the outer ring 25 of the bearing 22. 22 and the bearing 21 in the same area. Also in this case, the inner rings 26 of the bearing 21 and the bearing 22 are both joined to the rotating shaft 11 by a method such as press fitting or bonding. The outer ring 25 of the bearing 21 or the bearing 22 is disposed with a predetermined clearance with respect to the holding member 23. With such a configuration, the spring force of the preload spring acts on the outer ring 25 of the bearing 22 in a direction away from the bearing 21. Then, when this force is transmitted through the rotating shaft 11, a force acts on the inner ring 26 of the bearing 21 in the direction of the bearing 22. As a result, the positions of the outer race 25 and the inner race 26 in the bearings 21 and 22 are shifted in the axial direction, so that preload can be applied to the two bearings in the same manner as the above-described fixed position preload.

  When generating the constant-pressure preload, it is not always necessary to apply a spring force to the outer ring 25 of the bearing 22 as shown in FIG. For example, a spring force may be applied to the outer ring 25 of the bearing 21. In addition, one of the inner rings 26 of the bearings 21 and 22 is arranged with a predetermined clearance with respect to the rotating shaft 11, and the outer ring 25 of the bearings 21 and 22 is pressed into the holding member 23 or a method such as adhesion is used. By joining together, preload may be applied to the two bearings.

  Further, when a force is applied so that the inner ring 26 of the bearing 21 is separated from the bearing 22, it is better to apply a force so that the inner ring 26 of the bearing 22 is also separated from the bearing 21. Conversely, when a force is applied so that the inner ring 26 of the bearing 21 approaches the bearing 22, it is better to apply the force such that the inner ring 26 of the bearing 22 also approaches the bearing 21.

  When the rotary electric machine 10 is applied to a vehicle for the purpose of a vehicle power source or the like, there is a possibility that vibration having a component in a direction of generation of the preload may be applied to a mechanism that generates the preload, or a target to which the preload is applied. The direction of gravity applied to an object may change. Therefore, when the present rotating electric machine 10 is applied to a vehicle, it is desirable to employ a fixed position preload.

  The intermediate portion 45 has an annular inner shoulder 49a and an annular outer shoulder 49b. The outer shoulder portion 49b is located outside the inner shoulder portion 49a in the radial direction of the intermediate portion 45. The inner shoulder portion 49a and the outer shoulder portion 49b are separated from each other in the axial direction of the intermediate portion 45. Thus, the cylindrical portion 43 and the fixed portion 44 partially overlap in the radial direction of the intermediate portion 45. In other words, the cylindrical portion 43 protrudes outward in the axial direction from the base end of the fixing portion 44 (the lower end on the lower side in the figure). In this configuration, the rotor 40 can be supported on the rotating shaft 11 at a position near the center of gravity of the rotor 40 as compared with the case where the intermediate portion 45 is provided in a flat shape without a step. Forty stable operations can be realized.

  According to the configuration of the intermediate portion 45 described above, the rotor housing 40 has a bearing housing recess 46 that partially surrounds the bearing unit 20 at a position that surrounds the fixed portion 44 in the radial direction and is inward of the intermediate portion 45. Is formed in a ring shape, and encloses the bearing accommodation concave portion 46 in the radial direction and is located outside of the intermediate portion 45. The coil accommodation concave portion accommodates a coil end 54 of a stator winding 51 of a stator 50 described later. 47 are formed. These accommodation recesses 46 and 47 are arranged so as to be adjacent to each other inside and outside in the radial direction. That is, a part of the bearing unit 20 and the coil end 54 of the stator winding 51 are arranged so as to overlap inward and outward in the radial direction. Thus, the axial length of the rotating electric machine 10 can be reduced.

  The intermediate portion 45 is provided so as to project radially outward from the rotation shaft 11 side. A contact avoiding portion that extends in the axial direction and that avoids contact of the stator winding 51 of the stator 50 with the coil end 54 is provided in the intermediate portion 45. The intermediate portion 45 corresponds to the overhang portion.

  By bending the coil end 54 inward or outward in the radial direction, the axial dimension of the coil end 54 can be reduced, and the axial length of the stator 50 can be reduced. The bending direction of the coil end 54 may be a direction in which the coil end 54 and the rotor 40 are assembled. Assuming that the stator 50 is assembled radially inward of the rotor 40, the coil end 54 may be bent radially inward on the insertion tip side with respect to the rotor 40. The bending direction of the coil end on the side opposite to the coil end 54 may be arbitrary, but a shape bent outward with sufficient space is preferable in terms of manufacturing.

  Further, the magnet unit 42 as a magnet unit is configured by a plurality of permanent magnets arranged so that the polarity alternates along the circumferential direction inside the cylindrical unit 43 in the radial direction. Thereby, the magnet unit 42 has a plurality of magnetic poles in the circumferential direction. However, details of the magnet unit 42 will be described later.

  The stator 50 is provided radially inside the rotor 40. The stator 50 has a stator winding 51 wound in a substantially cylindrical (annular) shape, and a stator core 52 as a base member disposed radially inward of the stator winding 51. The line 51 is disposed so as to face the annular magnet unit 42 with a predetermined air gap interposed therebetween. The stator winding 51 includes a plurality of phase windings. Each of the phase windings is configured by connecting a plurality of conductors arranged in a circumferential direction at a predetermined pitch. In this embodiment, three-phase windings of U-phase, V-phase, and W-phase and three-phase windings of X-phase, Y-phase, and Z-phase are used, and by using two of these three-phase windings, The stator winding 51 is configured as a six-phase winding.

  The stator core 52 is formed in an annular shape from a laminated steel sheet in which electromagnetic steel sheets, which are soft magnetic materials, are laminated, and is assembled radially inside the stator winding 51. The electromagnetic steel sheet is, for example, a silicon steel sheet obtained by adding about several percent (for example, 3%) of silicon to iron. The stator winding 51 corresponds to an armature winding, and the stator core 52 corresponds to an armature core.

  The stator winding 51 is a portion that overlaps the stator core 52 in the radial direction, and is a coil side portion 53 that is radially outside the stator core 52, and one end of the stator core 52 in the axial direction and the other. It has coil ends 54 and 55 projecting to the end sides, respectively. The coil side portions 53 face the stator core 52 and the magnet unit 42 of the rotor 40 in the radial direction, respectively. When the stator 50 is disposed inside the rotor 40, the coil end 54 on the bearing unit 20 side (upper side in the drawing) of the coil ends 54 and 55 on both axial sides is a magnet holder of the rotor 40. It is housed in a coil housing recess 47 formed by 41. However, details of the stator 50 will be described later.

  The inverter unit 60 has a unit base 61 fixed to the housing 30 by fasteners such as bolts, and a plurality of electric components 62 attached to the unit base 61. The unit base 61 is made of, for example, carbon fiber reinforced plastic (CFRP). The unit base 61 has an end plate 63 fixed to the edge of the opening 33 of the housing 30 and a casing 64 provided integrally with the end plate 63 and extending in the axial direction. The end plate 63 has a circular opening 65 at the center thereof, and a casing 64 is formed so as to rise from the peripheral edge of the opening 65.

  The stator 50 is mounted on the outer peripheral surface of the casing 64. That is, the outer diameter of the casing 64 is the same as the inner diameter of the stator core 52 or slightly smaller than the inner diameter of the stator core 52. The stator 50 and the unit base 61 are integrated by attaching the stator core 52 to the outside of the casing 64. When the unit base 61 is fixed to the housing 30, the stator 50 is integrated with the housing 30 in a state where the stator core 52 is attached to the casing 64.

  The stator core 52 may be attached to the unit base 61 by bonding, shrink fitting, press fitting, or the like. Thereby, the displacement of the stator core 52 with respect to the unit base 61 in the circumferential direction or the axial direction is suppressed.

  A radially inner side of the casing 64 is a housing space for housing the electric component 62, and the electric component 62 is arranged in the housing space so as to surround the rotating shaft 11. The casing 64 has a role as an accommodation space forming part. The electric component 62 includes a semiconductor module 66 constituting an inverter circuit, a control board 67, and a capacitor module 68.

  The unit base 61 is provided radially inside the stator 50 and corresponds to a stator holder (armature holder) that holds the stator 50. The housing 30 and the unit base 61 constitute a motor housing of the rotary electric machine 10. In this motor housing, the holding member 23 is fixed to the housing 30 on one side in the axial direction with the rotor 40 interposed therebetween, and the housing 30 and the unit base 61 are connected to each other on the other side. For example, in an electric vehicle such as an electric vehicle, the rotating electric machine 10 is mounted on a vehicle or the like by attaching a motor housing to the vehicle or the like.

  Here, the configuration of the inverter unit 60 will be further described with reference to FIG. 6 which is an exploded view of the inverter unit 60 in addition to FIGS.

  In the unit base 61, the casing 64 has a cylindrical portion 71 and an end face 72 provided at one of the opposite ends in the axial direction (the end on the bearing unit 20 side). The opposite side of the end face 72 among both ends in the axial direction of the cylindrical portion 71 is entirely opened through the opening 65 of the end plate 63. A circular hole 73 is formed at the center of the end face 72, and the rotary shaft 11 can be inserted into the hole 73. The hole 73 is provided with a sealing material 171 that seals a gap between the hole 73 and the outer peripheral surface of the rotating shaft 11. The sealant 171 may be a sliding seal made of, for example, a resin material.

  The tubular portion 71 of the casing 64 serves as a partitioning portion between the rotor 40 and the stator 50 disposed radially outside the electrical component 62 disposed radially inward thereof. The rotor 40 and the stator 50 and the electric component 62 are arranged inward and outward in the radial direction with the shape portion 71 interposed therebetween.

  The electric component 62 is an electric component forming an inverter circuit, and has a powering function of rotating the rotor 40 by applying a current to each phase winding of the stator winding 51 in a predetermined order; And a power generation function of inputting a three-phase AC current flowing through the stator winding 51 with the rotation of the motor and outputting the generated power to the outside. The electric component 62 may have only one of the powering function and the power generation function. The power generation function is, for example, a regenerative function that outputs to the outside as regenerative power when the rotating electric machine 10 is used as a vehicle power source.

  As a specific configuration of the electrical component 62, as shown in FIG. 4, a hollow cylindrical capacitor module 68 is provided around the rotation shaft 11, and a plurality of capacitor modules 68 are provided on the outer peripheral surface of the capacitor module 68. Of semiconductor modules 66 are arranged side by side in the circumferential direction. The capacitor module 68 includes a plurality of smoothing capacitors 68a connected in parallel with each other. Specifically, the capacitor 68a is a laminated film capacitor in which a plurality of film capacitors are laminated, and has a trapezoidal cross section. The capacitor module 68 is configured by arranging twelve capacitors 68a in a ring.

  In the manufacturing process of the capacitor 68a, for example, a long film having a predetermined width formed by laminating a plurality of films is used, the film width direction is set to a trapezoidal height direction, and the upper and lower bases of the trapezoid alternate. The long film is cut into an equal-leg trapezoidal shape so that the capacitor element is formed. Then, by attaching electrodes and the like to the capacitor element, the capacitor 68a is manufactured.

  The semiconductor module 66 has a semiconductor switching element such as a MOSFET or an IGBT, and is formed in a substantially plate shape. In the present embodiment, since the rotating electric machine 10 includes two sets of three-phase windings and an inverter circuit is provided for each of the three-phase windings, a total of twelve semiconductor modules 66 are arranged in a ring. The assembled semiconductor module group 66A is provided in the electric component 62.

  The semiconductor module 66 is disposed between the cylindrical portion 71 of the casing 64 and the capacitor module 68. The outer peripheral surface of the semiconductor module group 66A is in contact with the inner peripheral surface of the cylindrical portion 71, and the inner peripheral surface of the semiconductor module group 66A is in contact with the outer peripheral surface of the capacitor module 68. In this case, the heat generated in the semiconductor module 66 is transmitted to the end plate 63 via the casing 64 and is released from the end plate 63.

  The semiconductor module group 66A preferably has a spacer 69 between the semiconductor module 66 and the cylindrical portion 71 in the outer peripheral surface side, that is, in the radial direction. In this case, in the capacitor module 68, the cross-sectional shape of the cross section orthogonal to the axial direction is a regular dodecagon, while the cross-sectional shape of the inner peripheral surface of the cylindrical portion 71 is circular. Has a flat surface and the outer peripheral surface is a curved surface. The spacer 69 may be provided integrally so as to be annularly continuous outside the semiconductor module group 66A in the radial direction. The spacer 69 is a good heat conductor, for example, a metal such as aluminum, or a heat dissipation gel sheet. Note that the cross-sectional shape of the inner peripheral surface of the cylindrical portion 71 can be the same dodecagon as that of the capacitor module 68. In this case, both the inner peripheral surface and the outer peripheral surface of the spacer 69 are preferably flat surfaces.

  Further, in the present embodiment, a cooling water passage 74 for flowing cooling water is formed in the cylindrical portion 71 of the casing 64, and heat generated in the semiconductor module 66 is supplied to the cooling water flowing through the cooling water passage 74. Is also released. That is, the casing 64 has a water cooling mechanism. As shown in FIGS. 3 and 4, the cooling water passage 74 is formed in an annular shape so as to surround the electric component 62 (the semiconductor module 66 and the capacitor module 68). The semiconductor module 66 is arranged along the inner peripheral surface of the cylindrical portion 71, and a cooling water passage 74 is provided at a position overlapping the semiconductor module 66 inward and outward in the radial direction.

  Since the stator 50 is disposed outside the tubular portion 71 and the electric component 62 is disposed inside, the heat of the stator 50 is transmitted to the tubular portion 71 from the outside, The heat of the electric component 62 (for example, the heat of the semiconductor module 66) is transmitted from the inside. In this case, the stator 50 and the semiconductor module 66 can be cooled at the same time, and the heat of the heat generating member in the rotating electric machine 10 can be efficiently released.

  Furthermore, at least a part of the semiconductor module 66 that constitutes a part or all of the inverter circuit that operates the rotating electric machine by energizing the stator winding 51 is disposed outside the cylindrical portion 71 of the casing 64 in the radial direction. Are arranged in a region surrounded by the stator core 52 arranged in the above. Desirably, the entirety of one semiconductor module 66 is arranged in a region surrounded by stator core 52. Further, desirably, the entirety of all the semiconductor modules 66 is arranged in a region surrounded by the stator core 52.

  Further, at least a part of the semiconductor module 66 is arranged in a region surrounded by the cooling water passage 74. Desirably, the entirety of all the semiconductor modules 66 is arranged in a region surrounded by the yoke 141.

  The electrical component 62 includes an insulating sheet 75 provided on one end face of the capacitor module 68 and a wiring module 76 provided on the other end face in the axial direction. In this case, the capacitor module 68 has two end faces facing each other in the axial direction, that is, a first end face and a second end face. The first end face of the capacitor module 68 near the bearing unit 20 is opposed to the end face 72 of the casing 64, and is superposed on the end face 72 with the insulating sheet 75 interposed therebetween. A wiring module 76 is mounted on a second end face of the capacitor module 68 near the opening 65.

  The wiring module 76 has a main body portion 76a made of a synthetic resin and having a circular plate shape, and a plurality of busbars 76b and 76c embedded therein. The busbars 76b and 76c allow the semiconductor module 66 and the capacitor to be mounted. An electrical connection is made with the module 68. Specifically, the semiconductor module 66 has a connection pin 66a extending from the axial end face, and the connection pin 66a is connected to the bus bar 76b on the radial outside of the main body portion 76a. The bus bar 76c extends on the outer side of the main body 76a in the radial direction on the side opposite to the capacitor module 68, and is connected to the wiring member 79 at its tip (see FIG. 2).

  As described above, according to the configuration in which the insulating sheet 75 is provided on the first end face of the capacitor module 68 facing in the axial direction and the wiring module 76 is provided on the second end face of the capacitor module 68, the heat radiation path of the capacitor module 68 A path is formed from the first end face and the second end face of the capacitor module 68 to the end face 72 and the cylindrical portion 71. That is, a path from the first end face to the end face 72 and a path from the second end face to the cylindrical portion 71 are formed. Thereby, heat can be radiated from the end face of the capacitor module 68 other than the outer peripheral face where the semiconductor module 66 is provided. That is, not only the heat radiation in the radial direction but also the heat radiation in the axial direction are possible.

  Further, since the capacitor module 68 has a hollow cylindrical shape and the rotating shaft 11 is disposed on the inner peripheral portion thereof with a predetermined gap interposed therebetween, the heat of the capacitor module 68 can be released from the hollow portion. ing. In this case, the flow of air is generated by the rotation of the rotating shaft 11, so that the cooling effect is enhanced.

  A disk-shaped control board 67 is attached to the wiring module 76. The control board 67 has a printed circuit board (PCB) on which a predetermined wiring pattern is formed. On the board, a control device 77 corresponding to a control unit including various ICs and a microcomputer is mounted. I have. The control board 67 is fixed to the wiring module 76 by a fixture such as a screw. The control board 67 has an insertion hole 67a at the center thereof, through which the rotating shaft 11 is inserted.

  The wiring module 76 has a first surface and a second surface that face each other in the axial direction, that is, that face each other in the thickness direction. The first surface faces the capacitor module 68. The wiring module 76 has a control board 67 on the second surface. The bus bar 76c of the wiring module 76 extends from one side of the both sides of the control board 67 to the other side. In such a configuration, the control board 67 may be provided with a notch for avoiding interference with the bus bar 76c. For example, a part of the outer edge of the circular control board 67 may be cut away.

  As described above, according to the configuration in which the electric component 62 is accommodated in the space surrounded by the casing 64 and the housing 30, the rotor 40, and the stator 50 are provided in layers outside the space, the electric component 62 is generated in the inverter circuit. Electromagnetic noise is suitably shielded. That is, in the inverter circuit, switching control in each semiconductor module 66 is performed using PWM control based on a predetermined carrier frequency, and electromagnetic noise may be generated by the switching control. It can be shielded suitably by the housing 30, the rotor 40, the stator 50, and the like outside in the radial direction of 62.

  Furthermore, by arranging at least a part of the semiconductor module 66 in a region surrounded by the stator core 52 arranged radially outside the cylindrical portion 71 of the casing 64, the semiconductor module 66 and the stator winding As compared with a configuration in which the magnetic flux 51 is disposed without passing through the stator core 52, even if a magnetic flux is generated from the semiconductor module 66, the magnetic flux is less likely to affect the stator winding 51. Further, even if a magnetic flux is generated from the stator winding 51, the magnetic flux hardly affects the semiconductor module 66. It is more effective if the entire semiconductor module 66 is arranged in a region surrounded by the stator core 52 arranged radially outside the cylindrical portion 71 of the casing 64. Further, when at least a part of the semiconductor module 66 is surrounded by the cooling water passage 74, it is possible to obtain an effect that heat from the stator winding 51 and the magnet unit 42 does not easily reach the semiconductor module 66.

  A through-hole 78 is formed near the end plate 63 in the cylindrical portion 71, through which a wiring member 79 (see FIG. 2) for electrically connecting the stator 50 on the outside and the electric component 62 on the inside is inserted. I have. As shown in FIG. 2, the wiring member 79 is connected to the end of the stator winding 51 and the bus bar 76c of the wiring module 76 by crimping, welding, or the like. The wiring member 79 is, for example, a bus bar, and its joint surface is desirably flattened. The through holes 78 may be provided at one or a plurality of positions. In the present embodiment, the through holes 78 are provided at two positions. In the configuration in which the through holes 78 are provided at two locations, the winding terminals extending from the two sets of three-phase windings can be easily connected by the wiring members 79, respectively, which is suitable for performing multiphase connection. It has become.

  As described above, the rotor 40 and the stator 50 are provided in the housing 30 in order from the radial outside as shown in FIG. 4, and the inverter unit 60 is provided radially inside the stator 50. Here, assuming that the radius of the inner peripheral surface of the housing 30 is d, the rotor 40 and the stator 50 are disposed radially outside the distance of d × 0.705 from the rotation center of the rotor 40. I have. In this case, of the rotor 40 and the stator 50, a region radially inward from the inner peripheral surface of the stator 50 on the radial inner side (that is, the inner peripheral surface of the stator core 52) is defined as a first region X1, Assuming that a region between the inner peripheral surface of the stator 50 and the housing 30 is the second region X2, the cross-sectional area of the first region X1 is larger than the cross-sectional area of the second region X2. I have. Further, when viewed in a range where the magnet unit 42 of the rotor 40 and the stator winding 51 overlap in the radial direction, the volume of the first region X1 is larger than the volume of the second region X2.

  Assuming that the rotor 40 and the stator 50 are magnetic circuit component assemblies, a first region X1 radially inward from the inner peripheral surface of the magnetic circuit component assembly in the housing 30 is formed in the magnetic circuit component assembly in the radial direction. Has a larger volume than the second region X2 between the inner peripheral surface and the housing 30.

  Next, the configurations of the rotor 40 and the stator 50 will be described in more detail.

  Generally, as a configuration of a stator in a rotating electric machine, there is known a configuration in which a plurality of slots are provided in a circumferential direction on a stator core made of laminated steel sheets and forming an annular shape, and a stator winding is wound in the slots. I have. Specifically, the stator core has a plurality of teeth extending in a radial direction at predetermined intervals from the yoke, and a slot is formed between adjacent teeth in the circumferential direction. A plurality of layers of conductors are accommodated in the slot, for example, in the radial direction, and the conductors constitute a stator winding.

  However, in the above-described stator structure, when the stator winding is energized, magnetic saturation occurs in the teeth of the stator core as the magnetomotive force of the stator winding increases, and as a result, the rotating electric machine It is possible that the torque density is limited. That is, in the stator core, it is considered that the magnetic flux is generated by energizing the stator windings and concentrates on the teeth, thereby causing magnetic saturation.

  In general, as a configuration of an IPM (Interior Permanent Magnet) rotor in a rotating electric machine, a configuration in which a permanent magnet is arranged on a d-axis in a dq coordinate system and a rotor core is arranged on a q-axis is known. In such a case, when the stator winding near the d-axis is excited, the excitation magnetic flux flows from the stator to the q-axis of the rotor according to Fleming's law. It is considered that this causes a wide range of magnetic saturation in the q-axis core portion of the rotor.

  FIG. 7 is a torque diagram showing the relationship between the ampere turn [AT] indicating the magnetomotive force of the stator winding and the torque density [Nm / L]. The dashed line indicates the characteristic in a general IPM rotor type rotating electric machine. As shown in FIG. 7, in a general rotating electric machine, by increasing the magnetomotive force in the stator, magnetic saturation occurs at two places, ie, the teeth portion between the slots and the q-axis core portion. The increase in torque is limited. As described above, in the general rotating electric machine, the ampere-turn design value is limited by A1.

  Therefore, in the present embodiment, the following configuration is provided to the rotating electric machine 10 in order to eliminate the limitation caused by the magnetic saturation. That is, as a first contrivance, a slotless structure is employed in the stator 50 in order to eliminate magnetic saturation caused by teeth of the stator core in the stator, and in order to eliminate magnetic saturation occurring in the q-axis core portion of the IPM rotor. , SPM (Surface Permanent Magnet) rotor. According to the first device, the above two portions where magnetic saturation occurs can be eliminated, but it is conceivable that the torque in the low current region decreases (see the dashed line in FIG. 7). Therefore, as a second contrivance, a pole anisotropic structure is adopted in which the magnet magnetic path is lengthened and the magnetic force is increased in the magnet unit 42 of the rotor 40 in order to recover the torque reduction by increasing the magnetic flux of the SPM rotor. ing.

  As a third measure, the coil side portion 53 of the stator winding 51 employs a flat conductive wire structure in which the radial thickness of the conductive wire in the stator 50 is reduced to recover the torque reduction. Here, it is conceivable that a larger eddy current is generated in the stator winding 51 facing the magnet unit 42 due to the above-described pole anisotropic structure in which the magnetic force is increased. However, according to the third device, the generation of radial eddy currents in the stator windings 51 can be suppressed because the flat conductive wire structure is thin in the radial direction. As described above, according to each of the first to third configurations, as shown by the solid line in FIG. 7, while a magnet having a high magnetic force is employed and torque characteristics are expected to be greatly improved, a magnet having a high magnetic force is used. Concerns about possible large eddy current generation can also be improved.

  Further, as a fourth contrivance, a magnet unit having a magnetic flux density distribution close to a sine wave using a polar anisotropic structure is employed. According to this, the torque can be increased by increasing the sine wave matching ratio by pulse control or the like described later, and eddy current loss (copper loss due to eddy current loss) due to a gradual change in magnetic flux compared to the radial magnet. ) Can also be further suppressed.

  Hereinafter, the sine wave matching ratio will be described. The sine wave matching ratio can be determined by comparing a measured waveform of the surface magnetic flux density distribution measured by tracing the surface of the magnet with a magnetic flux probe and a sine wave having the same period and peak value. The ratio of the amplitude of the primary waveform, which is the fundamental wave of the rotating electrical machine, to the amplitude of the actually measured waveform, that is, the amplitude of the fundamental wave plus other harmonic components, corresponds to the sine wave matching ratio. As the sine wave matching ratio increases, the waveform of the surface magnetic flux density distribution approaches a sine wave shape. When a primary sine-wave current is supplied from a inverter to a rotating electric machine having a magnet with an improved sine-wave matching ratio, the waveform of the surface magnetic flux density distribution of the magnet is close to a sine-wave shape. , A large torque can be generated. The surface magnetic flux density distribution may be estimated by a method other than the actual measurement, for example, an electromagnetic field analysis using Maxwell's equation.

  Further, as a fifth contrivance, the stator winding 51 has a strand conductor structure in which a plurality of strands are gathered and bundled. According to this, since the wires are connected in parallel, a large current can flow, and the generation of the eddy current generated in the conductors extending in the circumferential direction of the stator 50 in the flat conductor structure is reduced by the cross-sectional area of each of the wires. Can be more effectively suppressed than by reducing the thickness in the radial direction by the third device. And, by using a configuration in which a plurality of strands are twisted, the eddy current with respect to the magnetic flux generated by the right-handed screw rule in the direction of current flow can be offset with respect to the magnetomotive force from the conductor.

  As described above, when the fourth device and the fifth device are further added, the torque is increased while the eddy current loss caused by the high magnetic force is suppressed while employing the magnet having the high magnetic force as the second device. Can be planned.

  Hereinafter, the slotless structure of the stator 50, the flat conductor structure of the stator winding 51, and the pole anisotropic structure of the magnet unit 42 will be individually described. First, the slotless structure of the stator 50 and the flat conductor structure of the stator winding 51 will be described. FIG. 8 is a cross-sectional view of the rotor 40 and the stator 50, and FIG. 9 is an enlarged view of a part of the rotor 40 and the stator 50 shown in FIG. FIG. 10 is a cross-sectional view showing a cross section of the stator 50 along the line XX in FIG. 11, and FIG. 11 is a cross-sectional view showing a vertical cross section of the stator 50. FIG. 12 is a perspective view of the stator winding 51. 8 and 9, the magnetization directions of the magnets in the magnet unit 42 are indicated by arrows.

  As shown in FIGS. 8 to 11, the stator core 52 is formed by laminating a plurality of electromagnetic steel sheets in the axial direction, and has a cylindrical shape having a predetermined thickness in the radial direction, and is located on the rotor 40 side. The stator winding 51 is mounted radially outward. In the stator core 52, the outer peripheral surface on the rotor 40 side is a conductive wire installation portion (conductor area). The outer peripheral surface of the stator core 52 has a curved surface without irregularities, and a plurality of conductive wire groups 81 are arranged on the outer peripheral surface at predetermined intervals in the circumferential direction. The stator core 52 functions as a back yoke which is a part of a magnetic circuit for rotating the rotor 40. In this case, the teeth (that is, the iron core) made of the soft magnetic material are not provided between the two conductive wire groups 81 that are adjacent in the circumferential direction (that is, the slotless structure). In the present embodiment, a structure is such that the resin material of the sealing member 57 enters the gaps 56 between the conductive wire groups 81. That is, in the stator 50, the inter-conductor member provided between the respective conductor groups 81 in the circumferential direction is configured as the sealing member 57 which is a non-magnetic material. Speaking of the state before the sealing of the sealing member 57, on the radially outer side of the stator core 52, the conductor groups 81 are arranged at predetermined intervals in the circumferential direction with a gap 56 being a region between the conductors. Thus, a stator 50 having a slotless structure is constructed. In other words, each conductor group 81 is composed of two conductors 82 as described later, and only the non-magnetic material occupies between each two conductor groups 81 adjacent in the circumferential direction of the stator 50. I have. The non-magnetic material includes a non-magnetic gas such as air, a non-magnetic liquid, and the like in addition to the sealing member 57. In the following, the sealing member 57 is also referred to as a conductor-to-conductor member.

  Note that the configuration in which the teeth are provided between the conductor groups 81 arranged in the circumferential direction means that the teeth have a predetermined thickness in the radial direction and a predetermined width in the circumferential direction. It can be said that this is a configuration in which a part of the magnetic circuit, that is, a magnet magnetic path is formed between the magnetic circuits 81. In this regard, a configuration in which the teeth are not provided between the conductive wire groups 81 can be said to be a configuration in which the above-described magnetic circuit is not formed.

  As shown in FIG. 10, the stator winding (that is, the armature winding) 51 has a predetermined thickness T2 (hereinafter, also referred to as a first dimension) and a width W2 (hereinafter, also referred to as a second dimension). Is formed. The thickness T2 is the shortest distance between the outer surface and the inner surface facing each other in the radial direction of the stator winding 51. The width W2 is a fixed phase functioning as one of the polyphases of the stator winding 51 (three phases in the embodiment: three phases of U phase, V phase and W phase or three phases of X phase, Y phase and Z phase). This is the circumferential length of a part of the stator winding 51 of the slave winding 51. Specifically, in FIG. 10, when two conductor groups 81 adjacent to each other in the circumferential direction function as one of three phases, for example, a U-phase, the two conductor groups 81 in the circumferential direction end to end. Up to W2. The thickness T2 is smaller than the width W2.

  Note that the thickness T2 is preferably smaller than the total width dimension of the two conductive wire groups 81 existing within the width W2. If the cross-sectional shape of the stator winding 51 (more specifically, the conductive wire 82) is a perfect circle, an ellipse, or a polygon, among the cross-sections of the conductive wire 82 along the radial direction of the stator 50, In the section, the maximum length in the radial direction of the stator 50 may be W12, and in the section, the maximum length in the circumferential direction of the stator 50 may be W11.

  As shown in FIGS. 10 and 11, the stator winding 51 is sealed by a sealing member 57 made of a synthetic resin material as a sealing material (mold material). That is, the stator winding 51 is molded by the molding material together with the stator core 52. The resin can be regarded as Bs = 0 as a non-magnetic material or an equivalent of the non-magnetic material.

  10, the sealing member 57 is provided between the conductive wire groups 81, that is, the gap 56 is filled with a synthetic resin material. And an insulating member interposed therebetween. That is, the sealing member 57 functions as an insulating member in the gap 56. The sealing member 57 extends radially outside the stator core 52 in a range that includes all of the conductor groups 81, that is, in a range in which the radial thickness dimension is larger than the radial thickness dimension of each conductor group 81. Is provided.

  11, the sealing member 57 is provided in a range including the turn portion 84 of the stator winding 51. On the radially inner side of the stator winding 51, a sealing member 57 is provided in a range including at least a part of the end face of the stator core 52 facing the axial direction. In this case, the stator windings 51 are resin-sealed substantially at the ends of the phase windings of the respective phases, that is, substantially entirely except for connection terminals with the inverter circuit.

  In the configuration in which the sealing member 57 is provided in a range including the end face of the stator core 52, the sealing member 57 can press the laminated steel plate of the stator core 52 inward in the axial direction. Thereby, the laminated state of each steel plate can be maintained using the sealing member 57. Although the inner peripheral surface of the stator core 52 is not resin-sealed in the present embodiment, the entire stator core 52 including the inner peripheral surface of the stator core 52 is resin-sealed instead. It may be a configuration.

  When the rotating electric machine 10 is used as a vehicle power source, the sealing member 57 is made of a highly heat-resistant fluororesin, epoxy resin, PPS resin, PEEK resin, LCP resin, silicon resin, PAI resin, PI resin, or the like. Preferably, it is configured. Further, considering the coefficient of linear expansion from the viewpoint of suppressing cracking due to the difference in expansion, it is preferable that the material is the same as the outer coating of the conductor of the stator winding 51. That is, a silicone resin whose linear expansion coefficient is generally twice or more that of another resin is desirably excluded. In addition, in an electric product such as an electric vehicle that does not have an engine using combustion, a PPO resin, a phenol resin, and an FRP resin having a heat resistance of about 180 ° C. are also candidates. This is not the case in a field where the ambient temperature of the rotating electric machine can be regarded as being lower than 100 ° C.

  The torque of the rotating electric machine 10 is proportional to the magnitude of the magnetic flux. Here, when the stator core has teeth, the maximum magnetic flux amount at the stator is limited depending on the saturation magnetic flux density at the teeth, but the stator core does not have teeth. In such a case, the maximum magnetic flux amount at the stator is not limited. Therefore, the configuration is advantageous in increasing the current flowing through the stator winding 51 to increase the torque of the rotating electric machine 10.

In the present embodiment, the use of a structure (slotless structure) without teeth in the stator 50 reduces the inductance of the stator 50. Specifically, the inductance of the stator of a general rotating electrical machine in which a conductor is accommodated in each slot partitioned by a plurality of teeth is, for example, about 1 mH, whereas the inductance of the stator 50 of the present embodiment is about 1 mH. It is reduced to about 5 to 60 μH. In the present embodiment, the mechanical time constant Tm can be reduced by reducing the inductance of the stator 50 while using the rotating electric machine 10 having the outer rotor structure. That is, the mechanical time constant Tm can be reduced while increasing the torque. When the inertia is J, the inductance is L, the torque constant is Kt, and the back electromotive force constant is Ke, the mechanical time constant Tm is calculated by the following equation.
Tm = (J × L) / (Kt × Ke)
In this case, it can be confirmed that the mechanical time constant Tm is reduced by reducing the inductance L.

  Each conductive wire group 81 radially outside the stator core 52 is configured such that a plurality of conductive wires 82 having a flat rectangular cross section are arranged in the radial direction of the stator core 52. Each conductive wire 82 is arranged in a direction that satisfies “radial dimension <circumferential dimension” in a cross section. Thus, the thickness of each conductive wire group 81 in the radial direction is reduced. In addition, the thickness of the conductor region is reduced in the radial direction, and the conductor region extends flat to the region where the teeth are conventionally formed, so that the conductor region has a flat conductor region structure. As a result, an increase in the calorific value of the conductor, which may be caused by a reduction in the cross-sectional area due to the reduction in thickness, is suppressed by flattening in the circumferential direction to increase the cross-sectional area of the conductor. Note that, even in a configuration in which a plurality of conductors are arranged in the circumferential direction and are connected in parallel, an effect based on the same theory can be obtained, although the conductor cross-sectional area is reduced by the conductor coating. In the following, each of the conductive wire group 81 and each of the conductive wires 82 are also referred to as a conductive member.

  Since there is no slot, in the stator winding 51 of the present embodiment, the conductor area occupied by the stator winding 51 in one circumferential direction is designed to be larger than the conductor non-occupied area where the stator winding 51 does not exist. be able to. In the conventional rotating electrical machine for a vehicle, it is natural that the conductor region / conductor non-occupied region in one circumferential direction of the stator winding is 1 or less. On the other hand, in the present embodiment, each conductor group 81 is provided such that the conductor region is equal to the conductor non-occupied region or the conductor region is larger than the conductor non-occupied region. Here, as shown in FIG. 10, assuming that a conductor region in which the conductor 82 (that is, a straight line portion 83 described later) is disposed in the circumferential direction is WA and a region between conductors between adjacent conductors 82 is WB, The area WA is larger in the circumferential direction than the inter-wire area WB.

  As a configuration of the conductive wire group 81 in the stator winding 51, the radial thickness of the conductive wire group 81 is smaller than the circumferential width of one phase in one magnetic pole. That is, in a configuration in which the conductor group 81 is formed of two layers of conductors 82 in the radial direction and two conductor groups 81 are provided in the circumferential direction for one phase in one magnetic pole, the radial thickness of each conductor 82 is reduced. Tc, when the width of the conductor 82 in the circumferential direction is Wc, the configuration is such that “Tc × 2 <Wc × 2”. As another configuration, in a configuration in which the conductor group 81 is formed of two layers of conductors 82 and one conductor group 81 is provided in one magnetic pole in the circumferential direction for one phase, the relation of “Tc × 2 <Wc” is satisfied. It is good to be constituted so that it may become. In short, the conductor portions (conductor group 81) arranged at predetermined intervals in the circumferential direction in the stator winding 51 have a radial thickness that is larger than a circumferential width of one phase in one magnetic pole. It is small.

  In other words, each conductive wire 82 may have a thickness Tc in the radial direction smaller than a width Wc in the circumferential direction. Furthermore, the thickness (2Tc) in the radial direction of the wire group 81 composed of two layers of wires 82 in the radial direction, that is, the radial thickness (2Tc) of the wire group 81 is larger than the width Wc in the circumferential direction. Good to be small.

  The torque of rotating electric machine 10 is substantially inversely proportional to the radial thickness of stator core 52 of conductive wire group 81. In this regard, by reducing the thickness of the conductive wire group 81 on the radially outer side of the stator core 52, the configuration is advantageous in increasing the torque of the rotating electric machine 10. The reason is that the distance from the magnet unit 42 of the rotor 40 to the stator core 52 (that is, the distance of the portion without iron) can be reduced to reduce the magnetic resistance. According to this, the flux linkage of the stator core 52 by the permanent magnet can be increased, and the torque can be increased.

  In addition, since the thickness of the conductor group 81 is reduced, even if the magnetic flux leaks from the conductor group 81, it is easily collected by the stator core 52, and the magnetic flux leaks to the outside without being effectively used for improving the torque. Can be suppressed. That is, it is possible to suppress a decrease in magnetic force due to magnetic flux leakage, to increase the linkage magnetic flux of the stator core 52 by the permanent magnet, and to increase the torque.

  The conductor 82 (conductor) is formed of a covered conductor in which the surface of a conductor (conductor body) 82a is covered with an insulating film 82b, and between the conductors 82 that overlap each other in the radial direction, and between the conductor 82 and the stator core 52. In each case, insulation is ensured. The insulating coating 82b is formed of an insulating member that is laminated separately from the coating of the element wire 86 described later if the element wire 86 is a self-fused coated wire or the coating of the element wire 86. In addition, each of the phase windings constituted by the conductive wires 82 has an insulating property by the insulating coating 82b except for an exposed portion for connection. The exposed portion is, for example, an input / output terminal portion or a neutral point portion in the case of a star connection. In the conductive wire group 81, the conductive wires 82 adjacent to each other in the radial direction are fixed to each other by using a resin fixing or a self-sealing coated wire. This suppresses dielectric breakdown, vibration, and sound due to the rubbing of the conductive wires 82.

  In the present embodiment, the conductor 82a is configured as an aggregate of a plurality of wires 86. Specifically, as shown in FIG. 13, the conductor 82a is formed in a twisted yarn shape by twisting a plurality of strands 86. Further, as shown in FIG. 14, the strand 86 is configured as a composite in which thin fibrous conductive materials 87 are bundled. For example, the strand 86 is a composite of CNT (carbon nanotube) fibers, and as the CNT fibers, fibers including boron-containing fine fibers in which at least a part of carbon is replaced by boron are used. As the carbon-based fine fiber, a vapor grown carbon fiber (VGCF) or the like can be used in addition to the CNT fiber, but it is preferable to use the CNT fiber. The surface of the wire 86 is covered with a polymer insulating layer such as enamel. The surface of the wire 86 is preferably covered with a so-called enamel coating made of a polyimide coating or an amide imide coating.

  The conductor 82 forms an n-phase winding in the stator winding 51. The strands 86 of the conductor 82 (that is, the conductor 82a) are adjacent to each other in a contact state. The conducting wire 82 has, at one or more locations in the phase, a portion where the winding conductor is formed by twisting the plurality of strands 86, and the resistance between the twisted strands 86 is the strand 86 itself. The wire aggregate is larger than the resistance value. In other words, each two adjacent wires 86 have a first electrical resistivity in the adjacent direction, and if each of the wires 86 has a second electrical resistivity in its length direction, the first electrical resistivity The ratio has a value larger than the second electric resistivity. In addition, the conductor 82 may be formed by a plurality of strands 86, and may be a strand aggregate that covers the plurality of strands 86 with an insulating member having an extremely high first electrical resistivity. The conductor 82a of the conductor 82 is constituted by a plurality of twisted strands 86.

  In the conductor 82a, since the plurality of strands 86 are formed by twisting, generation of eddy current in each strand 86 is suppressed, and eddy current in the conductor 82a can be reduced. Further, since the strands 86 are twisted, portions where directions of applying the magnetic field are opposite to each other are generated in one strand 86, and the back electromotive voltage is canceled. Therefore, the eddy current can be reduced. In particular, by forming the wire 86 from the fibrous conductive material 87, it is possible to make the wire thinner and to remarkably increase the number of twists, so that the eddy current can be more suitably reduced.

  Here, the method of insulating the wires 86 is not limited to the above-described polymer insulating film, but may be a method of making current difficult to flow between the twisted wires 86 using contact resistance. That is, if the resistance value between the twisted strands 86 is larger than the resistance value of the strand 86 itself, the above effect can be obtained by the potential difference generated due to the difference in the resistance value. . For example, by using the manufacturing facility for producing the strand 86 and the production facility for producing the stator 50 (armature) of the rotary electric machine 10 as separate non-continuous facilities, the travel time, the working interval, and the like make it possible to use the strand. 86 is oxidized and the contact resistance can be increased, which is preferable.

  As described above, the conducting wire 82 has a flat rectangular shape in cross section, and is arranged in a plurality in the radial direction. For example, the conducting wire 82 is covered with a self-sealing covered wire including a fusion layer and an insulating layer. Are assembled in a twisted state, and the fusion layers are fused together to maintain the shape. In addition, you may shape | mold in the state which twisted the strand which does not have a fusion | melting layer, or the strand of a self-fusion | bonding coating wire with a synthetic resin etc. to a desired shape. When the thickness of the insulating film 82b in the conductor 82 is, for example, 80 μm to 100 μm and is thicker than the thickness of a commonly used conductor (5 to 40 μm), the insulation between the conductor 82 and the stator core 52 is provided. Even without paper or the like, the insulation between the two can be ensured.

  Further, it is desirable that the insulating coating 82b has a higher insulating performance than the insulating layer of the strand 86, and is configured to be able to insulate between the phases. For example, when the thickness of the polymer insulating layer of the wire 86 is set to, for example, about 5 μm, the thickness of the insulating coating 82b of the conductive wire 82 is set to about 80 μm to 100 μm so that the interphase insulation can be suitably performed. Is desirable.

  Further, the conductive wire 82 may have a configuration in which a plurality of strands 86 are bundled without being twisted. In other words, the conductor 82 has a configuration in which a plurality of strands 86 are twisted in the entire length, a configuration in which a plurality of strands 86 are twisted in a part of the entire length, and a plurality of strands 86 in the entire length. Instead, any one of the bundled configurations may be used. In summary, each of the conductors 82 constituting the conductor portion includes a plurality of strands 86 bundled together, and a wire aggregate in which the resistance value between the bundled strands is larger than the resistance value of the strand 86 itself. Has become.

  Each conductive wire 82 is bent and formed so as to be arranged in a predetermined arrangement pattern in the circumferential direction of the stator winding 51, whereby a phase winding for each phase is formed as the stator winding 51. . As shown in FIG. 12, in the stator winding 51, a coil side portion 53 is formed by a straight portion 83 extending linearly in the axial direction of each of the conductors 82, and is located on both outer sides of the coil side portion 53 in the axial direction. The coil ends 54 and 55 are formed by the projecting turn portions 84. Each conductor 82 is configured as a series of corrugated conductors by alternately repeating a straight portion 83 and a turn portion 84. The linear portions 83 are disposed at positions radially opposed to the magnet unit 42, and the linear portions 83 of the same phase, which are arranged at predetermined intervals at a position outside the magnet unit 42 in the axial direction, They are connected to each other by a turn part 84. Note that the straight portion 83 corresponds to a “magnet facing portion”.

  In the present embodiment, the stator winding 51 is formed in an annular shape by distributed winding. In this case, in the coil side portion 53, linear portions 83 are arranged in the circumferential direction at intervals corresponding to one pole pair of the magnet unit 42 for each phase, and in the coil ends 54 and 55, the linear portions 83 for each phase are arranged. , Are connected to each other by a turn portion 84 formed in a substantially V shape. The straight portions 83 forming a pair corresponding to one pole pair have current directions opposite to each other. Also, the combination of the pair of linear portions 83 connected by the turn portion 84 is different between the one coil end 54 and the other coil end 55, and the connection at the coil ends 54, 55 is made in the circumferential direction. By repeating, the stator winding 51 is formed in a substantially cylindrical shape.

  More specifically, the stator winding 51 constitutes a winding for each phase using two pairs of conducting wires 82 for each phase, and one of the three windings (U Phase, V phase, W phase) and the other three-phase winding (X phase, Y phase, Z phase) are provided in two layers inside and outside in the radial direction. In this case, if the number of phases of the stator winding 51 is S (six in the embodiment) and the number of conductors 82 per phase is m, 2 × S × m = 2Sm conductors for each pole pair 82 will be formed. In the present embodiment, since the number of phases S is 6, the number m is 4, and the rotating electric machine has 8 pole pairs (16 poles), 6 × 4 × 8 = 192 conductors 82 are formed around the stator core 52. It is arranged in the direction.

  In the stator winding 51 shown in FIG. 12, in the coil side portion 53, the linear portions 83 are arranged so as to overlap in two layers adjacent in the radial direction, and at the coil ends 54 and 55, the linear portions 83 which overlap in the radial direction are arranged. From 83, the turn portion 84 is configured to extend in the circumferential direction in directions opposite to each other in the circumferential direction. In other words, in each of the radially adjacent conductors 82, the directions of the turn portions 84 are opposite to each other except for the end of the stator winding 51.

  Here, the winding structure of the conducting wire 82 in the stator winding 51 will be specifically described. In the present embodiment, a plurality of conducting wires 82 formed by a wave winding are provided so as to overlap with a plurality of layers (for example, two layers) adjacent in the radial direction. FIGS. 15A and 15B are diagrams showing the form of each conductor 82 in the n-th layer. FIG. 15A shows the shape of each conductor 82 viewed from the side of the stator winding 51. FIG. 15B shows the shape of the conductive wire 82 as viewed from one axial side of the stator winding 51. 15 (a) and FIG. 15 (b), the positions where the conductor groups 81 are arranged are indicated as D1, D2, D3,. Also, for convenience of explanation, only three conductive wires 82 are shown, which are a first conductive wire 82_A, a second conductive wire 82_B, and a third conductive wire 82_C.

  In each of the conductors 82_A to 82_C, the straight portions 83 are arranged at the position of the n-th layer, that is, at the same position in the radial direction, and the straight portions 83 separated from each other by six positions (3 × m pairs) in the circumferential direction. They are connected to each other by a turn part 84. In other words, in each of the conductors 82 </ b> _A to 82 </ b> _C, on both ends of the seven linear portions 83 adjacent to each other in the circumferential direction of the stator winding 51 on the same circle centered on the axis of the rotor 40. The two are connected to each other by one turn 84. For example, in the first conductive wire 82 </ b> _A, a pair of straight portions 83 are arranged at D <b> 1 and D <b> 7, respectively, and the pair of straight portions 83 are connected by an inverted V-shaped turn portion 84. The other conductors 82_B and 82_C are arranged in the same n-th layer with their circumferential positions shifted one by one. In this case, since each of the conductive wires 82_A to 82_C is disposed in the same layer, the turn portions 84 may interfere with each other. Therefore, in the present embodiment, an interference avoiding portion in which a part thereof is radially offset is formed in the turn portion 84 of each of the conductive wires 82_A to 82_C.

  Specifically, the turn portion 84 of each of the conductors 82_A to 82_C is formed by a single inclined portion 84a which is a portion extending in the circumferential direction on the same circle (first circle), and the same circle from the inclined portion 84a. Also shifts radially inward (upward in FIG. 15 (b)) to reach another circle (second circle), the top portion 84b, the inclined portion 84c extending in the circumferential direction on the second circle, and the first circle. And a return portion 84d that returns to the second circle. The top portion 84b, the inclined portion 84c, and the return portion 84d correspond to an interference avoiding portion. Note that the inclined portion 84c may be configured to shift radially outward with respect to the inclined portion 84a.

  That is, the turn portion 84 of each of the conductors 82_A to 82_C has a slope portion 84a on one side and a slope portion 84c on the other side on both sides of the top portion 84b, which is a central position in the circumferential direction. The radial positions of the inclined portions 84a and 84c (positions in the front-rear direction in FIG. 15A, positions in the up-down direction in FIG. 15B) are different from each other. For example, the turn portion 84 of the first conductive wire 82 </ b> _A extends in the circumferential direction from the position D <b> 1 of the n-layer as a starting point, and bends in the radial direction (for example, radially inward) at the top portion 84 b which is the central position in the circumferential direction. By turning again in the circumferential direction, it extends again in the circumferential direction, and further turns again in the radial direction (for example, radially outward) at the return portion 84d, thereby reaching the D7 position of the n-layer, which is the end point position. I have.

  According to the above configuration, in each of the conductors 82_A to 82_C, one of the inclined portions 84a is vertically arranged in order from the top in the order of the first conductor 82_A → the second conductor 82_B → the third conductor 82_C, and the conductors 82_AＡ 82_C is turned upside down, and the other inclined portions 84c are arranged vertically from the top in the order of the third conductor 82_C → the second conductor 82_B → the first conductor 82_A. Therefore, the conductors 82_A to 82_C can be arranged in the circumferential direction without interfering with each other.

  Here, in a configuration in which a plurality of conductive wires 82 are superposed in the radial direction to form a conductive wire group 81, a turn portion 84 connected to the radially inner straight portion 83 of the plurality of linear portions 83 and a radially outer straight portion 83 are formed. It is preferable that the turn portions 84 connected to the straight portions 83 are arranged further apart from each other in the radial direction than the straight portions 83. Further, when a plurality of layers of the conductive wires 82 are bent to the same side in the radial direction near the end of the turn portion 84, that is, near the boundary with the linear portion 83, the insulation between the conductive wires 82 of the adjacent layers is caused by the interference. Should not be impaired.

  For example, in D7 to D9 of FIGS. 15A and 15B, the respective conducting wires 82 overlapping in the radial direction are bent in the radial direction at the return portion 84d of the turn portion 84, respectively. In this case, as shown in FIG. 16, the radius of curvature of the bent portion may be different between the conductor 82 of the n-th layer and the conductor 82 of the (n + 1) -th layer. Specifically, the radius of curvature R1 of the conductive wire 82 on the radially inner side (nth layer) is made smaller than the radius of curvature R2 of the conductive wire 82 on the radially outer side (n + 1th layer).

  Further, it is preferable that the amount of shift in the radial direction be different between the conductive wire 82 of the nth layer and the conductive wire 82 of the (n + 1) th layer. Specifically, the shift amount S1 of the radially inner (n-th layer) conductive wire 82 is made larger than the shift amount S2 of the radially outer (n + 1-th layer) conductive wire 82.

  According to the above configuration, even when the conductive wires 82 overlapping in the radial direction are bent in the same direction, mutual interference between the conductive wires 82 can be preferably avoided. Thereby, good insulating properties are obtained.

  Next, the structure of the magnet unit 42 in the rotor 40 will be described. In the present embodiment, it is assumed that the magnet unit 42 is made of a permanent magnet and has a residual magnetic flux density Br = 1.0 [T] and a specific coercive force Hcj = 400 [kA / m] or more. In short, the permanent magnet used in the present embodiment is a sintered magnet obtained by sintering and solidifying a granular magnetic material, and has a specific coercive force Hcj on the JH curve of 400 [kA / m] or more. And the residual magnetic flux density Br is 1.0 [T] or more. When 5,000 to 10,000 [AT] is applied by inter-phase excitation, the magnetic pole length of one pole pair, that is, the north pole and the south pole, in other words, the magnetic flux between the north pole and the south pole flows through the magnet. If a permanent magnet having a length of 25 [mm] is used, Hcj = 10000 [A], which indicates that demagnetization does not occur.

  In other words, the magnet unit 42 has a saturation magnetic flux density Js of 1.2 [T] or more, a crystal grain size of 10 [μm] or less, and Js × α is 1 when the orientation ratio is α. 0.0 [T] or more.

  Hereinafter, the magnet unit 42 will be supplemented. The magnet unit 42 (magnet) is characterized in that 2.15 [T] ≧ Js ≧ 1.2 [T]. In other words, examples of the magnet used for the magnet unit 42 include NdFe11TiN, Nd2Fe14B, Sm2Fe17N3, and a FeNi magnet having an L10 type crystal. It should be noted that configurations such as SmCo5, FePt, Dy2Fe14B, and CoPt, which are generally called samakoba, cannot be used. It should be noted that Dy2Fe14B and Nd2Fe14B generally use heavy rare earth dysprosium like Dy2Fe14B and Dy2Fe14B. May satisfy 2.15 [T] ≧ Js ≧ 1.2 [T], and this case is also applicable. In such a case, it is referred to as ([Nd1-xDyx] 2Fe14B), for example. Furthermore, two or more magnets having different compositions, for example, magnets made of two or more materials such as FeNi plus Sm2Fe17N3 can be achieved. For example, Js = 1.6 [T] and Js This can be achieved even by a mixed magnet having a coercive force increased by mixing a small amount of Js <1 [T], for example, Dy2Fe14B, with a marginal Nd2Fe14B magnet.

  In addition, in a rotating electric machine operated at a temperature outside the range of human activity, for example, 60 ° C. or more, which is higher than the temperature in the desert, for example, in a motor application for a vehicle in which the temperature in a vehicle is close to 80 ° C. in summer, In particular, it is desirable to include components of FeNi and Sm2Fe17N3 having a small temperature dependence coefficient. This is due to the temperature-dependent coefficient in the motor operation from the temperature state near -40 ° C in Northern Europe, which is within the human activity range, to 60 ° C or more, which exceeds the desert temperature described above, or to the heat-resistant temperature of the coil enamel coating of about 180 to 240 ° C. This is because the motor characteristics are greatly different from each other, which makes it difficult to perform optimal control and the like with the same motor driver. If FeNi or Sm2Fe17N3 having the L10 type crystal is used, the load on the motor driver can be reduced appropriately because of its characteristic that it has a temperature dependence coefficient of half or less as compared with Nd2Fe14B.

  In addition, the magnet unit 42 is characterized in that the particle size in a fine powder state before orientation is 10 μm or less and a single domain particle size or more using the above-described magnet composition. In magnets, the coercive force is increased by reducing the size of powder particles to the order of several hundreds of nm. In recent years, powders that have been made as fine as possible have been used in recent years. However, if the particle size is too small, the BH product of the magnet decreases due to oxidation or the like. It is known that when the particle diameter is up to a single magnetic domain particle diameter, the coercive force increases due to miniaturization. The size of the particle diameter described here is the size of the particle diameter in a fine powder state in the orientation step in the magnet manufacturing process.

  Further, each of the first magnet 91 and the second magnet 92 of the magnet unit 42 is a sintered magnet formed by so-called sintering of magnetic powder baked at a high temperature. In this sintering, when the saturation magnetization Js of the magnet unit 42 is 1.2 T or more, the crystal grain sizes of the first magnet 91 and the second magnet 92 are 10 μm or less, and the orientation ratio is α, Js × α is It is performed so as to satisfy the condition of 1.0 T (tesla) or more. Each of the first magnet 91 and the second magnet 92 is sintered so as to satisfy the following conditions. Then, by performing orientation in the orientation step in the manufacturing process, unlike the definition of the magnetic force direction in the magnetizing step of the isotropic magnet, it has an orientation ratio (orientation ratio). When the saturation magnetization Js of the magnet unit 42 of the present embodiment is 1.2 T or more, the orientation ratio α of the first magnet 91 and the second magnet 92 is so high that Jr ≧ Js × α ≧ 1.0 [T]. The orientation ratio is set. Note that the orientation ratio α here refers to, for example, in each of the first magnet 91 or the second magnet 92, there are six easy axes, and five of them have the same direction, that is, the direction A10. Α = 5/6 when one of them faces the direction B10 inclined at 90 degrees to the direction A10, and when one of the other faces the direction B10 inclined at 45 degrees to the direction A10, Since the component facing one direction A10 is cos45 ° = 0.707, α = (5 + 0.707) / 6. In the present embodiment, the first magnet 91 and the second magnet 92 are formed by sintering, but if the above conditions are satisfied, the first magnet 91 and the second magnet 92 may be formed by another method. . For example, a method of forming an MQ3 magnet or the like can be adopted.

  In this embodiment, the permanent magnet whose easy axis of magnetization is controlled by the orientation is used. Therefore, the magnetic circuit length inside the magnet is set to be equal to the magnetic circuit length of a linearly oriented magnet that conventionally outputs 1.0 [T] or more. In comparison, it can be longer. In other words, a magnetic circuit length per pole pair can be achieved with a small amount of magnets, and the reversible demagnetization range is maintained even when exposed to severe high-temperature conditions, compared to a design using conventional linearly-oriented magnets. Can be. In addition, the inventor of the present application has found a configuration that can obtain characteristics close to those of a polar anisotropic magnet even when a conventional magnet is used.

  The axis of easy magnetization refers to a crystal orientation that is easily magnetized by the magnet. The direction of the axis of easy magnetization in the magnet is a direction in which the degree of orientation indicating the degree of alignment of the direction of the axis of easy magnetization is 50% or more, or a direction in which the orientation of the magnet is average.

  As shown in FIGS. 8 and 9, the magnet unit 42 has an annular shape and is provided inside the magnet holder 41 (specifically, inside the cylindrical portion 43 in the radial direction). The magnet unit 42 is a polar anisotropic magnet and has a first magnet 91 and a second magnet 92 having different polarities. The first magnets 91 and the second magnets 92 are alternately arranged in the circumferential direction. The first magnet 91 is a magnet forming an N pole in a portion near the stator winding 51, and the second magnet 92 is a magnet forming an S pole in a portion near the stator winding 51. The first magnet 91 and the second magnet 92 are permanent magnets made of a rare earth magnet such as a neodymium magnet.

  As shown in FIG. 9, each of the magnets 91 and 92 has a d-axis (direct-axis), which is the center of the magnetic pole, and a magnetic pole boundary between the N pole and the S pole in a known dq coordinate system (in other words, the magnetic flux density Is 0 Tesla) and the magnetization direction extends in an arc shape with respect to the q-axis (quadrature-axis). In each of the magnets 91 and 92, the magnetization direction is the radial direction of the annular magnet unit 42 on the d-axis side, and the magnetization direction of the annular magnet unit 42 is the circumferential direction on the q-axis side. Hereinafter, this will be described in more detail. As shown in FIG. 9, each of the magnets 91 and 92 has a first portion 250 and two second portions 260 located on both sides of the first portion 250 in the circumferential direction of the magnet unit 42. In other words, the first portion 250 is closer to the d-axis than the second portion 260, and the second portion 260 is closer to the q-axis than the first portion 250. The magnet unit 42 is configured such that the direction of the easy axis 300 of the first portion 250 is more parallel to the d axis than the direction of the easy axis 310 of the second portion 260. In other words, the magnet unit 42 is configured such that the angle θ11 between the easy axis 300 of the first portion 250 and the d axis is smaller than the angle θ12 between the easy axis 310 of the second portion 260 and the q axis. I have.

  More specifically, the angle θ11 is an angle formed between the d axis and the easy axis 300 when the direction from the stator 50 (armature) toward the magnet unit 42 is positive on the d axis. The angle θ12 is an angle formed between the q axis and the easy axis 310 when the direction from the stator 50 (armature) toward the magnet unit 42 is positive on the q axis. Note that both the angle θ11 and the angle θ12 are 90 ° or less in the present embodiment. Here, each of the easy axes 300 and 310 has the following definition. In each part of the magnets 91 and 92, when one easy axis of magnetization is oriented in the direction A11 and the other easy axis is oriented in the direction B11, the cosine of the angle θ between the direction A11 and the direction B11 is obtained. The absolute value (| cos θ |) is defined as the easy axis 300 or the easy axis 310.

  That is, each of the magnets 91 and 92 has a different direction of the axis of easy magnetization on the d-axis side (portion closer to the d-axis) and on the q-axis side (portion closer to the q-axis). The direction of the easy axis is close to the direction parallel to the d-axis, and the direction of the easy axis of magnetization is close to the direction orthogonal to the q-axis on the q-axis side. An arc-shaped magnet magnetic path is formed in accordance with the direction of the axis of easy magnetization. In each of the magnets 91 and 92, the easy axis may be oriented parallel to the d axis on the d-axis side, and the easy axis may be orthogonal to the q axis on the q-axis side.

  In the magnets 91 and 92, the stator-side outer surface of the magnets 91 and 92 on the stator 50 side (the lower side in FIG. 9) and the end surface on the q-axis side in the circumferential direction form a magnetic flux. It is a magnetic flux acting surface which is an inflow / outflow surface, and a magnet magnetic path is formed so as to connect those magnetic flux acting surfaces (an outer surface on the stator side and an end surface on the q-axis side).

  In the magnet unit 42, the magnetic flux flows in an arc between the adjacent N and S poles by the magnets 91 and 92, so that the magnet magnetic path is longer than, for example, a radial anisotropic magnet. Therefore, as shown in FIG. 17, the magnetic flux density distribution becomes close to a sine wave. As a result, unlike the magnetic flux density distribution of the radial anisotropic magnet shown as a comparative example in FIG. 18, the magnetic flux can be concentrated on the center side of the magnetic pole, and the torque of the rotating electric machine 10 can be increased. Further, in the magnet unit 42 of the present embodiment, it can be confirmed that there is a difference in the magnetic flux density distribution as compared with the conventional Halbach array magnet. 17 and 18, the horizontal axis represents the electrical angle, and the vertical axis represents the magnetic flux density. 17 and 18, 90 ° on the horizontal axis indicates the d-axis (that is, the center of the magnetic pole), and 0 ° and 180 ° on the horizontal axis indicate the q-axis.

  That is, according to each of the magnets 91 and 92 having the above configuration, the magnet magnetic flux on the d-axis is strengthened, and the change in magnetic flux near the q-axis is suppressed. Thereby, it is possible to suitably realize the magnets 91 and 92 in which the surface magnetic flux changes gradually from the q axis to the d axis in each magnetic pole.

  The sine wave matching ratio of the magnetic flux density distribution may be, for example, 40% or more. In this way, the amount of magnetic flux in the center portion of the waveform can be reliably improved as compared with the case of using a radially oriented magnet or a parallelly oriented magnet having a sine wave matching ratio of about 30%. Further, when the sine wave matching ratio is 60% or more, the amount of magnetic flux at the center portion of the waveform can be reliably improved as compared with a magnetic flux concentration array such as a Halbach array.

  In the radial anisotropic magnet shown in FIG. 18, the magnetic flux density changes sharply near the q-axis. As the change in the magnetic flux density becomes steeper, the eddy current generated in the stator winding 51 increases. Further, the magnetic flux change on the stator winding 51 side also becomes steep. On the other hand, in the present embodiment, the magnetic flux density distribution has a magnetic flux waveform close to a sine wave. For this reason, near the q-axis, the change in the magnetic flux density is smaller than the change in the magnetic flux density of the radial anisotropic magnet. Thereby, generation of eddy current can be suppressed.

  In the magnet unit 42, a magnetic flux is generated in a direction orthogonal to the magnetic flux acting surface 280 on the stator 50 near the d-axis of each of the magnets 91 and 92 (that is, the center of the magnetic pole). As the distance from the surface 280 increases, the shape of the arc increases as the distance from the d-axis increases. Further, the more the magnetic flux is perpendicular to the magnetic flux acting surface, the stronger the magnetic flux becomes. In this regard, in the rotating electric machine 10 of the present embodiment, since the conductor groups 81 are thinned in the radial direction as described above, the radial center position of the conductor groups 81 approaches the magnetic flux acting surface of the magnet unit 42, The stator 50 can receive a strong magnet magnetic flux from the rotor 40.

  Further, the stator 50 is provided with a cylindrical stator core 52 radially inside the stator winding 51, that is, on the opposite side of the rotor 40 with the stator winding 51 interposed therebetween. Therefore, the magnetic flux extending from the magnetic flux acting surfaces of the magnets 91 and 92 is attracted to the stator core 52 and orbits while using the stator core 52 as a part of the magnetic path. In this case, the direction and path of the magnet magnetic flux can be optimized.

  Hereinafter, as a method of manufacturing the rotating electric machine 10, a procedure for assembling the bearing unit 20, the housing 30, the rotor 40, the stator 50, and the inverter unit 60 shown in FIG. 5 will be described. The inverter unit 60 has a unit base 61 and an electric component 62 as shown in FIG. 6, and each operation process including a process of assembling the unit base 61 and the electric component 62 will be described. In the following description, an assembly including the stator 50 and the inverter unit 60 is referred to as a first unit, and an assembly including the bearing unit 20, the housing 30, and the rotor 40 is referred to as a second unit.

This manufacturing process
A first step of mounting the electrical component 62 inside the unit base 61 in the radial direction;
A second step of mounting the unit base 61 on the radially inner side of the stator 50 to produce a first unit;
A third step of manufacturing the second unit by inserting the fixing portion 44 of the rotor 40 into the bearing unit 20 assembled in the housing 30;
A fourth step of mounting the first unit radially inside the second unit;
A fifth step of fastening and fixing the housing 30 and the unit base 61;
have. The order of execution of these steps is first step → second step → third step → fourth step → fifth step.

  According to the manufacturing method described above, after assembling the bearing unit 20, the housing 30, the rotor 40, the stator 50, and the inverter unit 60 as a plurality of assemblies (subassemblies), the assemblies are assembled. Easy handling and complete inspection of each unit can be realized, and a reasonable assembly line can be constructed. Therefore, it is possible to easily cope with multi-product production.

  In the first step, a good heat conductor having good heat conduction is adhered to at least one of the radially inner side of the unit base 61 and the radially outer side of the electric component 62 by coating, bonding, or the like. It is preferable to mount the electric component 62 on the unit base 61. Thus, heat generated by the semiconductor module 66 can be effectively transmitted to the unit base 61.

  In the third step, the insertion of the rotor 40 may be performed while maintaining the coaxial relationship between the housing 30 and the rotor 40. Specifically, for example, the position of the outer peripheral surface of the rotor 40 (the outer peripheral surface of the magnet holder 41) or the inner peripheral surface of the rotor 40 (the inner peripheral surface of the magnet unit 42) is determined with reference to the inner peripheral surface of the housing 30. Using the jig, the housing 30 and the rotor 40 are assembled while sliding either the housing 30 or the rotor 40 along the jig. This makes it possible to mount a heavy component without applying an unbalanced load to the bearing unit 20, and the reliability of the bearing unit 20 is improved.

  In the fourth step, the first unit and the second unit may be assembled while maintaining coaxiality between the first unit and the second unit. Specifically, for example, a jig that determines the position of the inner peripheral surface of the unit base 61 with reference to the inner peripheral surface of the fixing portion 44 of the rotor 40 is used, and the first unit and the second unit are moved along the jig. Assemble these units while sliding any of them. As a result, it is possible to assemble the rotor 40 and the stator 50 while preventing mutual interference between the extremely small gaps. Defective products can be eliminated.

  The order of each of the above steps may be the second step → the third step → the fourth step → the fifth step → the first step. In this case, the delicate electric component 62 is assembled last, and the stress on the electric component 62 in the assembling process can be minimized.

  Next, a configuration of a control system that controls the rotating electric machine 10 will be described. FIG. 19 is an electric circuit diagram of a control system of the rotating electric machine 10, and FIG. 20 is a functional block diagram illustrating a control process performed by the control device 110.

  In FIG. 19, two sets of three-phase windings 51a and 51b are shown as the stator winding 51. The three-phase winding 51a includes a U-phase winding, a V-phase winding, and a W-phase winding. The phase winding 51b includes an X-phase winding, a Y-phase winding, and a Z-phase winding. A first inverter 101 and a second inverter 102 each corresponding to a power converter are provided for each of the three-phase windings 51a and 51b. The inverters 101 and 102 are configured by full-bridge circuits having the same number of upper and lower arms as the number of phases of the phase windings, and the switches (semiconductor switching elements) provided on each arm are turned on and off to turn the stator windings 51 on and off. The conduction current is adjusted in each phase winding.

  A DC power supply 103 and a smoothing capacitor 104 are connected in parallel to each of the inverters 101 and 102. The DC power supply 103 is configured by, for example, an assembled battery in which a plurality of cells are connected in series. Each switch of the inverters 101 and 102 corresponds to the semiconductor module 66 shown in FIG. 1 and the like, and the capacitor 104 corresponds to the capacitor module 68 shown in FIG. 1 and the like.

  The control device 110 includes a microcomputer including a CPU and various memories. Based on various detection information in the rotating electric machine 10 and requests for powering drive and power generation, the control of the power supply is performed by turning on and off the switches in the inverters 101 and 102. carry out. Control device 110 corresponds to control device 77 shown in FIG. The detection information of the rotating electric machine 10 includes, for example, a rotation angle (electrical angle information) of the rotor 40 detected by an angle detector such as a resolver, a power supply voltage (inverter input voltage) detected by a voltage sensor, and a current sensor. , The energized current of each phase detected by Control device 110 generates and outputs an operation signal for operating each switch of inverters 101 and 102. The power generation request is, for example, a request for regenerative driving when the rotating electric machine 10 is used as a vehicle power source.

  The first inverter 101 includes a series connection of an upper arm switch Sp and a lower arm switch Sn in three phases including a U phase, a V phase, and a W phase. The high potential side terminal of the upper arm switch Sp of each phase is connected to the positive terminal of the DC power supply 103, and the low potential side terminal of the lower arm switch Sn of each phase is connected to the negative terminal (ground) of the DC power supply 103. . One end of each of a U-phase winding, a V-phase winding, and a W-phase winding is connected to an intermediate connection point between the upper arm switch Sp and the lower arm switch Sn of each phase. These phase windings are star-connected (Y connection), and the other ends of the phase windings are connected to each other at a neutral point.

  The second inverter 102 has a configuration similar to that of the first inverter 101, and includes a series connection of an upper arm switch Sp and a lower arm switch Sn in three phases including an X phase, a Y phase, and a Z phase. ing. The high potential side terminal of the upper arm switch Sp of each phase is connected to the positive terminal of the DC power supply 103, and the low potential side terminal of the lower arm switch Sn of each phase is connected to the negative terminal (ground) of the DC power supply 103. . One end of each of an X-phase winding, a Y-phase winding, and a Z-phase winding is connected to an intermediate connection point between the upper arm switch Sp and the lower arm switch Sn of each phase. These phase windings are star-connected (Y connection), and the other ends of the phase windings are connected to each other at a neutral point.

  FIG. 20 shows current feedback control processing for controlling the U, V, and W phase currents, and current feedback control processing for controlling the X, Y, and Z phase currents. Here, the control process on the U, V, and W phases will be described first.

  20, a current command value setting unit 111 uses a torque-dq map, and based on a powering torque command value or a power generation torque command value for the rotary electric machine 10 and an electric angular velocity ω obtained by time-differentiating the electric angle θ. , A d-axis current command value and a q-axis current command value are set. The current command value setting unit 111 is provided in common on the U, V, and W phase sides and the X, Y, and Z phase sides. The power generation torque command value is, for example, a regenerative torque command value when the rotating electric machine 10 is used as a vehicle power source.

  The dq conversion unit 112 converts a current detection value (three phase currents) obtained by a current sensor provided for each phase into a quadrature 2 with a direction of an axis of a magnetic field, or field direction as a d-axis. It is converted into a d-axis current and a q-axis current which are components of the three-dimensional rotation coordinate system.

  The d-axis current feedback control unit 113 calculates a d-axis command voltage as an operation amount for feedback-controlling the d-axis current to a d-axis current command value. Further, the q-axis current feedback control unit 114 calculates a q-axis command voltage as an operation amount for feedback-controlling the q-axis current to a q-axis current command value. In each of these feedback control units 113 and 114, the command voltage is calculated using the PI feedback method based on the deviation of the d-axis current and the q-axis current from the current command value.

  The three-phase converter 115 converts the d-axis and q-axis command voltages into U-phase, V-phase, and W-phase command voltages. Each of the units 111 to 115 is a feedback control unit that performs the feedback control of the fundamental wave current based on the dq conversion theory, and the U-phase, V-phase, and W-phase command voltages are the feedback control values.

  Then, the operation signal generation unit 116 generates an operation signal for the first inverter 101 based on the three-phase command voltage using a known triangular wave carrier comparison method. Specifically, the operation signal generation unit 116 performs a PWM control based on a magnitude comparison between a signal obtained by standardizing a three-phase command voltage with a power supply voltage and a carrier signal such as a triangular wave signal, and thereby switches the upper and lower arms in each phase. An operation signal (duty signal) is generated.

  The same configuration is also provided on the X, Y, and Z phase sides. The dq conversion unit 122 outputs a current detection value (three phase currents) obtained by a current sensor provided for each phase to the field direction. It is converted into a d-axis current and a q-axis current, which are components of an orthogonal two-dimensional rotating coordinate system having a d-axis.

  The d-axis current feedback controller 123 calculates a d-axis command voltage, and the q-axis current feedback controller 124 calculates a q-axis command voltage. The three-phase converter 125 converts d-axis and q-axis command voltages into X-phase, Y-phase, and Z-phase command voltages. Then, the operation signal generation unit 126 generates an operation signal for the second inverter 102 based on the three-phase command voltage. Specifically, the operation signal generation unit 126 performs a PWM control based on a magnitude comparison between a signal obtained by standardizing a three-phase command voltage with a power supply voltage and a carrier signal such as a triangular wave signal, and thereby switches the upper and lower arms in each phase. An operation signal (duty signal) is generated.

  The driver 117 turns on and off the three-phase switches Sp and Sn of the inverters 101 and 102 based on the switch operation signals generated by the operation signal generation units 116 and 126.

  Subsequently, the torque feedback control processing will be described. This process is used mainly for the purpose of increasing the output of the rotating electric machine 10 and reducing the loss under operating conditions in which the output voltage of each of the inverters 101 and 102 becomes large, such as in a high rotation region and a high output region. The control device 110 selects and executes one of the torque feedback control process and the current feedback control process based on the operating conditions of the rotating electric machine 10.

  FIG. 21 shows a torque feedback control process corresponding to the U, V, and W phases and a torque feedback control process corresponding to the X, Y, and Z phases. In FIG. 21, the same components as those in FIG. 20 are denoted by the same reference numerals, and description thereof will be omitted. Here, the control process on the U, V, and W phases will be described first.

  The voltage amplitude calculation unit 127 is a command value for the magnitude of the voltage vector based on the powering torque command value or the power generation torque command value for the rotary electric machine 10 and the electrical angular velocity ω obtained by time-differentiating the electrical angle θ. Calculate the voltage amplitude command.

  The torque estimating unit 128a calculates an estimated torque value corresponding to the U, V, and W phases based on the d-axis current and the q-axis current converted by the dq converting unit 112. Note that the torque estimating unit 128a may calculate the voltage amplitude command based on the map information in which the d-axis current, the q-axis current, and the voltage amplitude command are related.

  The torque feedback control unit 129a calculates a voltage phase command, which is a command value of a voltage vector phase, as an operation amount for performing feedback control of the torque estimation value to the powering torque command value or the power generation torque command value. The torque feedback control unit 129a calculates a voltage phase command using a PI feedback method based on the deviation of the estimated torque value from the powering torque command value or the generated torque command value.

  The operation signal generator 130a generates an operation signal for the first inverter 101 based on the voltage amplitude command, the voltage phase command, and the electrical angle θ. Specifically, the operation signal generation unit 130a calculates a three-phase command voltage based on the voltage amplitude command, the voltage phase command, and the electrical angle θ, and standardizes the calculated three-phase command voltage with the power supply voltage. And PWM control based on a magnitude comparison between the signal and a carrier signal such as a triangular wave signal to generate switch operation signals for the upper and lower arms in each phase.

  Incidentally, the operation signal generation unit 130a is based on a pulse pattern information, a voltage amplitude command, a voltage phase command, and an electrical angle θ, which are map information in which the voltage amplitude command, the voltage phase command, the electric angle θ and the switch operation signal are related. Thus, a switch operation signal may be generated.

  The X-, Y-, and Z-phase sides also have the same configuration, and the torque estimating unit 128b determines the X, Y, and Z-axis currents based on the d-axis current and the q-axis current converted by the dq converting unit 122. An estimated torque value corresponding to the Z phase is calculated.

  The torque feedback control unit 129b calculates a voltage phase command as an operation amount for performing feedback control of the torque estimation value to the powering torque command value or the power generation torque command value. The torque feedback control unit 129b calculates the voltage phase command using the PI feedback method based on the deviation of the estimated torque value from the powering torque command value or the generated torque command value.

  The operation signal generator 130b generates an operation signal for the second inverter 102 based on the voltage amplitude command, the voltage phase command, and the electrical angle θ. Specifically, the operation signal generation unit 130b calculates a three-phase command voltage based on the voltage amplitude command, the voltage phase command, and the electrical angle θ, and standardizes the calculated three-phase command voltage with the power supply voltage. And PWM control based on a magnitude comparison between the signal and a carrier signal such as a triangular wave signal to generate switch operation signals for the upper and lower arms in each phase. The driver 117 turns on and off the three-phase switches Sp and Sn in the inverters 101 and 102 based on the switch operation signals generated by the operation signal generation units 130a and 130b.

  Incidentally, the operation signal generation unit 130b is based on the voltage amplitude command, the voltage phase command, the pulse pattern information that is the map information associated with the electrical angle θ and the switch operation signal, the voltage amplitude command, the voltage phase command, and the electrical angle θ. Thus, a switch operation signal may be generated.

  By the way, in the rotary electric machine 10, there is a concern that the bearings 21 and 22 may be eroded by the generation of the shaft current. For example, when the energization of the stator winding 51 is switched by switching, a slight shift in switching timing (switching imbalance) causes distortion of magnetic flux, and as a result, bearings 21 and 22 supporting the rotating shaft 11 are caused. It is feared that electrolytic corrosion will occur in the case. The distortion of the magnetic flux is generated in accordance with the inductance of the stator 50, and the axial electromotive voltage generated by the distortion of the magnetic flux causes dielectric breakdown in the bearings 21 and 22, and the electrolytic corrosion proceeds.

  In this regard, in the present embodiment, the following three measures are taken as measures against electrolytic corrosion. The first countermeasure against electric erosion is a countermeasure against electric erosion by reducing the inductance with the coreless stator 50 and making the magnet magnetic flux of the magnet unit 42 gentle. The second countermeasure against electric corrosion is a countermeasure against electric corrosion by using a cantilever structure of the rotating shaft with the bearings 21 and 22. The third countermeasure against electrolytic corrosion is a countermeasure against electrolytic corrosion caused by molding the annular stator winding 51 together with the stator core 52 using a molding material. The details of each of these measures will be described individually below.

  First, in the first countermeasures against electrolytic corrosion, the stator 50 is made of teethless between the conductor groups 81 in the circumferential direction, and sealed between each conductor group 81 by a nonmagnetic material instead of the teeth (iron core). The member 57 is provided (see FIG. 10). Thereby, the inductance of the stator 50 can be reduced. By reducing the inductance in the stator 50, even if a switching timing shift occurs when the stator windings 51 are energized, the occurrence of magnetic flux distortion due to the switching timing shift is suppressed, and the bearings 21 and 22 are further reduced. It is possible to suppress the electric erosion. It is preferable that the d-axis inductance is equal to or less than the q-axis inductance.

  Further, the magnets 91 and 92 are configured such that the orientation of the easy axis of magnetization is parallel to the d-axis on the d-axis side as compared with the q-axis side (see FIG. 9). As a result, the magnetic flux on the d-axis is strengthened, and the change in the surface magnetic flux (increase / decrease in magnetic flux) from the q-axis to the d-axis becomes gentle at each magnetic pole. Therefore, a rapid voltage change due to the switching imbalance is suppressed, and the configuration can contribute to suppressing electrolytic corrosion.

  In the second countermeasures against electrolytic corrosion, in the rotating electric machine 10, the bearings 21 and 22 are arranged so as to be deviated to one of the axial directions with respect to the axial center of the rotor 40 (see FIG. 2). Thereby, the influence of electrolytic corrosion can be reduced as compared with a configuration in which a plurality of bearings are provided on both sides of the rotor in the axial direction. In other words, in a configuration in which the rotor is supported at both ends by a plurality of bearings, a closed circuit that passes through the rotor, the stator, and each bearing (that is, each bearing on both sides in the axial direction with the rotor interposed therebetween) is generated as high-frequency magnetic flux is generated. It is formed, and there is a concern that the shaft current causes electrolytic corrosion of the bearing. On the other hand, in a configuration in which the rotor 40 is cantilevered by the plurality of bearings 21 and 22, the closed circuit is not formed, and the electrolytic corrosion of the bearing is suppressed.

  In addition, the rotating electric machine 10 has the following configuration in association with the configuration for one-sided arrangement of the bearings 21 and 22. In the magnet holder 41, a contact avoiding portion that extends in the axial direction and avoids contact with the stator 50 is provided at an intermediate portion 45 that projects in the radial direction of the rotor 40 (see FIG. 2). In this case, when a closed circuit of the shaft current is formed via the magnet holder 41, the length of the closed circuit can be increased to increase the circuit resistance. Thereby, it is possible to suppress the electrolytic corrosion of the bearings 21 and 22.

  The holding member 23 of the bearing unit 20 is fixed to the housing 30 on one side in the axial direction with the rotor 40 interposed therebetween, and the housing 30 and the unit base 61 (stator holder) are connected to each other on the other side. (See FIG. 2). According to the present configuration, it is possible to suitably realize a configuration in which the bearings 21 and 22 are biased on one side in the axial direction of the rotating shaft 11. Further, in this configuration, since the unit base 61 is connected to the rotating shaft 11 via the housing 30, the unit base 61 can be arranged at a position electrically separated from the rotating shaft 11. If an insulating member such as a resin is interposed between the unit base 61 and the housing 30, the unit base 61 and the rotating shaft 11 are further electrically separated. Thereby, the electrolytic corrosion of the bearings 21 and 22 can be appropriately suppressed.

  In the rotating electric machine 10 according to the present embodiment, the shaft voltage acting on the bearings 21 and 22 is reduced by arranging the bearings 21 and 22 on one side or the like. Further, the potential difference between the rotor 40 and the stator 50 is reduced. Therefore, the potential difference acting on the bearings 21 and 22 can be reduced without using conductive grease in the bearings 21 and 22. Since the conductive grease generally contains fine particles such as carbon, it is considered that sound is generated. In this regard, in this embodiment, the bearings 21 and 22 are configured to use non-conductive grease. For this reason, it is possible to suppress the inconvenience of generating noise in the bearings 21 and 22. For example, when it is applied to an electric vehicle such as an electric vehicle, it is considered that a countermeasure against the noise of the rotating electric machine 10 is required. However, the countermeasure against the noise can be suitably implemented.

  In the third countermeasure against electrolytic corrosion, the stator winding 51 is molded together with the stator core 52 with a molding material to suppress the displacement of the stator winding 51 in the stator 50 (see FIG. 11). ). In particular, in the rotating electric machine 10 of the present embodiment, since there is no inter-conductor member (teeth) between the respective conductor groups 81 in the circumferential direction of the stator winding 51, there is a concern that a displacement may occur in the stator winding 51. It is conceivable that the stator winding 51 is molded together with the stator core 52 so that the displacement of the conductor wire of the stator winding 51 is suppressed. Therefore, it is possible to suppress the distortion of the magnetic flux due to the displacement of the stator winding 51 and the occurrence of electrolytic corrosion of the bearings 21 and 22 due to the distortion.

  In addition, since the unit base 61 as a housing member for fixing the stator core 52 is made of carbon fiber reinforced plastic (CFRP), discharge to the unit base 61 is suppressed as compared with a case where the unit base 61 is made of, for example, aluminum. As a result, a suitable countermeasure against electric corrosion is possible.

  In addition, as a countermeasure against electrolytic corrosion of the bearings 21 and 22, it is also possible to use a configuration in which at least one of the outer race 25 and the inner race 26 is made of a ceramic material, or an insulating sleeve is provided outside the outer race 25.

  Hereinafter, another embodiment will be described focusing on differences from the first embodiment.

(2nd Embodiment)
In the second embodiment, the configuration of the magnet unit 42 of the first embodiment is changed. Hereinafter, the configuration of the magnet unit 42 will be described in detail mainly. As shown in FIGS. 22 and 23, the magnet unit 42 has a plurality of magnets 2001 arranged side by side in the circumferential direction. Each of these magnets 2001 is oriented such that the direction of the axis of easy magnetization is parallel to the d-axis on the d-axis side, which is the center of the magnetic pole, as compared to the q-axis side, which is the boundary of the magnetic poles. A magnet magnetic path is formed along.

  In the magnet unit 42, the magnetization directions (magnetization directions) of the adjacent magnets 2001 in the circumferential direction are reversed (reverse) so that the polarities of the adjacent d-axes in the circumferential direction are different. In other words, the magnetization directions of the magnet 2001 are made different so that the d-axis, in which the magnetic flux is concentrated and the polarity is N-pole, and the d-axis, in which the magnetic flux is diffused and the polarity is the S-pole, alternate in the circumferential direction. ing.

  More specifically, as shown in FIG. 23, a plurality of arc-shaped magnet magnetic paths are formed around a center point set on the q-axis. This magnet magnetic path includes a magnetic path on the oriented circular arc OA centering on the center point and passing through a first intersection point P1 between the d-axis and the stator-side outer surface (armature-side peripheral surface) of the magnet 2001. It is desirable that the oriented arc OA be set such that the tangent at the first intersection P1 on the oriented arc approaches parallel to the d-axis.

  The magnet 2001 is provided symmetrically with respect to the q-axis, and is provided between d-axes adjacent in the circumferential direction. That is, the magnet 2001 is provided in an arc shape along the circumferential direction between the adjacent d-axes in the circumferential direction. More specifically, the oriented arc OA is provided between the d-axes adjacent in the circumferential direction, and the magnet 2001 is arranged so that a magnetic path is formed at least over the entire area of the oriented arc OA. It is provided between adjacent d-axes in the direction.

  Accordingly, of the magnet magnetic paths of the magnet 2001, the magnet magnetic path along the oriented arc OA is the longest, and the further away from the oriented arc OA, the shorter the magnet magnetic path is. For example, in a portion of the magnet magnetic path of the magnet 2001 closer to the q-axis, a magnet magnetic path (indicated by a broken line) passing through a portion closer to the stator than an opposite stator is more likely to be shorter. . Further, for example, in a portion of the magnet magnetic path of the magnet 2001 closer to the d-axis, a magnet magnetic path (shown by a broken line) passing through a portion on the side opposite to the stator than the portion on the stator is more likely to be shorter. ing. The shape of the magnet magnetic path (that is, the oriented arc OA) may be an arc that is a part of a perfect circle or an arc that is a part of an ellipse. The center of the arc is on the q-axis, but need not be on the q-axis.

  The magnet unit 42 is provided in an annular shape by arranging arc-shaped magnets 2001 each having a magnet magnetic path formed in this manner in the circumferential direction.

  By the way, as described above, it is desirable that the magnet unit 42 has a surface magnetic flux density distribution close to a sine wave shape, and that the magnetic flux density on the d-axis be as high as possible. Therefore, when the magnets 2001 are arranged side by side in the circumferential direction, it is desirable to reduce the gap between the adjacent magnets 2001 as much as possible and to reduce the number thereof. Incidentally, when radially oriented magnets and parallel oriented magnets are arranged in the circumferential direction without gaps, the magnetic flux density changes sharply near the q-axis as shown in FIG. For this reason, when a radially oriented magnet or a parallelly oriented magnet is employed, they are usually arranged at predetermined intervals.

  However, when the magnets 2001 are arranged without gaps, there is no space for arranging an engaging portion (a side wall or the like) that engages with the circumferential end surface of the magnet 2001. Even if a gap is provided, it is better to make the width dimension of the gap in the circumferential direction as short as possible (thin) in order to obtain a surface magnetic flux density distribution close to a sine wave shape and to increase the magnetic flux density in the d-axis. . In that case, it is difficult to dispose the engaging portion having such a strength (that is, the width dimension) that it can be prevented from rotating due to the clearance. Therefore, in the second embodiment, the magnet 2001 and the cylindrical portion 43 of the magnet unit 42 are configured as follows. In the second embodiment, the magnet holder 41 corresponds to a magnet holding unit.

  A concave portion 2002 is provided on the anti-stator-side peripheral surface (anti-armature-side peripheral surface) of the magnet unit 42 along the axial direction. The concave portion 2002 opens on the side opposite to the stator (the cylindrical portion side). The concave portion 2002 is provided on the d-axis side rather than the q-axis side. In FIG. 23, the concave portion 2002 is configured to open around the d-axis. More specifically, in each magnet 2001, a slope that is oblique to the radial direction (for example, an angle of 45 degrees) is provided so as to cut the corner on the side opposite to the stator. Accordingly, in a state where the magnets 2001 are arranged side by side in the circumferential direction, the magnet unit 42 is provided with a concave portion 2002 that opens on the side opposite to the stator around the d-axis. Further, the concave portion 2002 is provided so as to avoid the alignment arc OA.

  As described above, in a portion of the magnet magnetic path of the magnet 2001 closer to the d-axis, a magnet magnetic path (indicated by a broken line) that passes through a portion on the anti-stator side rather than the stator side is shorter. It is easy to become. When the magnet magnetic path is short, it can be said that the magnetic field is easily demagnetized due to the influence of the external magnetic field (for example, the magnetic field from the stator winding 51). For this reason, even if the concave portion 2002 is provided in the portion of the magnet 2001 closer to the d-axis on the side opposite to the stator, the magnetic flux density on the d-axis is hardly affected (the magnetic flux density does not decrease).

  On the other hand, the cylindrical portion 43 is provided with a convex portion 2003 that engages with the concave portion 2002 of the magnet 2001 in the circumferential direction. More specifically, as shown in FIG. 23, a convex portion 2003 is provided on the inner peripheral surface of the cylindrical portion 43 so as to project toward the magnet portion (that is, the stator side) along the radial direction. These convex portions 2003 are formed so that the width in the circumferential direction becomes shorter as approaching the stator side in the radial direction so that the cross section becomes triangular according to the shape of the concave portion 2002. That is, a slope is provided from the inner peripheral surface of the cylindrical portion 43 to the vertex of the convex portion 2003, and the slope is formed at an angle corresponding to the angle of the slope of the concave portion 2002 (that is, at an angle of 45 degrees with respect to the radial direction). ) Is formed. Further, the dimension (height dimension) of the convex portion 2003 in the radial direction is the same as the dimension (depth dimension) of the concave portion 2002. This makes it possible to suitably engage the convex portion 2003 and the concave portion 2002.

  Note that the convex portion 2003 and the concave portion 2002 may be formed at any location within the range of the magnet unit 42 in the axial direction. For example, the convex portion 2003 and the concave portion 2002 may be provided over the entire range of the magnet unit 42 along the axial direction. Further, the projections 2003 and the recesses 2002 do not need to be provided on all d-axes, and may be smaller than the number of d-axes. For example, the convex portion 2003 and the concave portion 2002 may be provided at every 90-degree angle interval. If the number of the concave portions 2002 is larger than that of the convex portions 2003, the numbers of the convex portions 2003 and the concave portions 2002 may be arbitrarily changed.

  Further, a groove 2004 is provided along the axial direction on the stator-side outer surface (armature-side peripheral surface) of the magnet unit 42 of the second embodiment. The groove 2004 is open on the stator side. The groove 2004 is provided on the q-axis side more than the d-axis side. In FIG. 23, the groove 2004 is formed so as to open around the q-axis. In this case, the groove 2004 is provided so as to avoid the orientation arc OA.

  When the rotor 40 is arranged to face the stator 50, the stator 50 (the stator winding 51 and the like) is arranged inside the magnet unit 42 from the radially inner diameter. For this reason, by providing the groove 2004, the magnet unit 42 is provided with a flow path surrounded by the groove 2004 and the stator 50. The flow path functions as a passage penetrating in the axial direction, and is configured to allow a fluid such as air to pass therethrough. That is, the cross-sectional area of the groove 2004 is large enough to allow a fluid such as air to pass through.

  As described above, in a portion of the magnet magnetic path of the magnet 2001 closer to the q-axis, a magnet magnetic path (shown by a broken line) passing through a portion closer to the stator than an opposite stator is shorter. It is easy to become. When the magnet magnetic path is short, it can be said that the magnetic field is easily demagnetized due to the influence of the external magnetic field (for example, the magnetic field from the stator winding 51). For this reason, even if the groove 2004 is provided in the portion of the magnet 2001 closer to the stator than the side opposite to the stator in the q-axis, the magnetic flux density on the d-axis is hardly affected (the magnetic flux density is reduced). Does not drop).

  In the second embodiment, the magnet unit 42 is configured by the plurality of magnets 2001, but the magnet unit 42 may be configured by one annular magnet 2001.

  According to the second embodiment, the following excellent effects are obtained.

  On the d-axis side that is the center of the magnetic pole, the direction of the easy axis is oriented so as to be parallel to the d-axis as compared with the q-axis side that is the magnetic pole boundary, and a magnet magnetic path is formed along the easy axis. The plurality of magnets 2001 are used for the magnet unit 42. In this case, in order to obtain a magnetic flux density distribution close to a sine wave shape and to increase the magnetic flux density on the d-axis, it is desirable to reduce the gap between the magnets 2001 adjacent in the circumferential direction as much as possible. However, when the gap between the adjacent magnets 2001 is reduced, the engagement portion disposed in the gap becomes thin, and it becomes impossible to suitably perform the rotation stop.

  By the way, in the portion near the d-axis of the magnet 2001, the portion on the side opposite to the stator is a portion where the magnet magnetic path is easily shortened and demagnetized easily. That is, even if this portion is deleted, the influence on the magnetic flux density generated from the d-axis is small. That is, the magnetic flux density generated from the d-axis does not decrease, and the torque does not decrease.

  Therefore, a concave portion 2002 that opens on the anti-stator side, that is, on the cylindrical portion side, is provided in the portion of the magnet unit 42 on the anti-stator side (cylindrical portion side) and on the d-axis side of the q-axis. The cylindrical portion 43 is provided with a convex portion 2003 that engages with the concave portion 2002. Accordingly, the rotation of the magnet unit 42 can be stopped while providing a magnetic flux density distribution close to a sine wave shape and increasing the magnetic flux density on the d-axis.

  Also, the widths of the concave portion 2002 and the convex portion 2003 in the circumferential direction (the width of the opening of the concave portion 2002 and the width of the base of the convex portion 2003) are set so as to secure the strength that can appropriately perform the rotation stop. You have set. For this reason, it is possible to suitably perform the detent. Even when the width is set as described above, since the portion is easily demagnetized, the magnetic flux in the d-axis can be reduced even when the concave portion 2002 is provided as compared with the case where the concave portion 2002 is not provided. A decrease in density can be suppressed. Further, the magnet amount of the magnet unit 42 can be reduced.

  Further, in the magnet 2001, in the portion near the q-axis, the portion on the stator side is a portion in which the magnet magnetic path is likely to be short and easily demagnetized. That is, even if this portion is deleted, the influence on the magnetic flux density generated from the d-axis is small.

  Therefore, a groove portion 2004 is provided in a portion closer to the stator in a portion closer to the q-axis. Since these grooves 2004 and are provided along the axial direction, the magnet 2001 is fixed to the inner peripheral surface of the cylindrical portion 43, and the rotor 40 is arranged to face the stator 50 so as to penetrate in the axial direction. A flow path will be provided. When the rotor 40 rotates, a fluid such as air passes through these flow paths, so that the magnet unit 42 is cooled. That is, the cooling performance of the magnet unit 42 can be improved.

  In addition, as described above, since the groove 2004 is provided in a portion where demagnetization is likely to occur, the magnetic flux density is hardly affected. That is, the cooling performance of the magnet unit 42 can be improved while suppressing a decrease in torque. Further, the amount of magnets of the magnet unit 42 can be suitably reduced while suppressing a decrease in torque.

(Third embodiment)
In the present embodiment, the pole anisotropic structure of the magnet unit 42 in the rotor 40 is changed, and will be described in detail below.

  As shown in FIGS. 24 and 25, the magnet unit 42 is configured using a magnet array called a Halbach array. That is, the magnet unit 42 includes the first magnet 131 having the magnetization direction (the direction of the magnetization vector) in the radial direction and the second magnet 132 having the magnetization direction (the direction of the magnetization vector) in the circumferential direction. The first magnets 131 are arranged at predetermined intervals in the circumferential direction, and the second magnets 132 are arranged at positions between the adjacent first magnets 131 in the circumferential direction. The first magnet 131 and the second magnet 132 are permanent magnets made of a rare earth magnet such as a neodymium magnet.

  The first magnets 131 are circumferentially separated from each other such that poles on the side facing the stator 50 (radially inward) alternately become N poles and S poles. The second magnets 132 are arranged adjacent to the first magnets 131 so that the polarities alternate in the circumferential direction. The cylindrical portion 43 provided to surround each of the magnets 131 and 132 is preferably a soft magnetic core made of a soft magnetic material, and functions as a back core. The magnet unit 42 of the second embodiment also has the same relationship of the easy axis to the d axis and the q axis in the dq coordinate system as in the first embodiment.

  A magnetic body 133 made of a soft magnetic material is disposed radially outside the first magnet 131, that is, on the side of the cylindrical portion 43 of the magnet holder 41. For example, the magnetic body 133 may be made of an electromagnetic steel sheet, soft iron, or a powdered iron core material. In this case, the circumferential length of the magnetic body 133 is the same as the circumferential length of the first magnet 131 (in particular, the circumferential length of the outer peripheral portion of the first magnet 131). Further, the radial thickness of the integrated body in a state where the first magnet 131 and the magnetic body 133 are integrated is the same as the radial thickness of the second magnet 132. In other words, the thickness of the first magnet 131 in the radial direction is smaller than that of the second magnet 132 by the amount of the magnetic body 133. The magnets 131 and 132 and the magnetic body 133 are fixed to each other by, for example, an adhesive. In the magnet unit 42, the radial outside of the first magnet 131 is on the opposite side to the stator 50, and the magnetic body 133 is located on the opposite side (anti- On the stator side).

  On the outer peripheral portion of the magnetic body 133, a key 134 is formed as a projection projecting radially outward, that is, toward the cylindrical portion 43 of the magnet holder 41. Further, a key groove 135 is formed on the inner peripheral surface of the cylindrical portion 43 as a concave portion for accommodating the key 134 of the magnetic body 133. The protruding shape of the key 134 and the groove shape of the key groove 135 are the same, and the same number of key grooves 135 as the keys 134 are formed corresponding to the keys 134 formed on each magnetic body 133. By the engagement of the key 134 and the key groove 135, the positional displacement of the first magnet 131 and the second magnet 132 and the magnet holder 41 in the circumferential direction (rotation direction) is suppressed. The key 134 and the key groove 135 (convex portion and concave portion) may be provided in any of the cylindrical portion 43 of the magnet holder 41 and the magnetic member 133, and conversely, on the outer peripheral portion of the magnetic member 133. In addition to providing the key groove 135, it is also possible to provide the key 134 on the inner peripheral portion of the cylindrical portion 43 of the magnet holder 41.

  Here, in the magnet unit 42, the magnetic flux density of the first magnet 131 can be increased by alternately arranging the first magnets 131 and the second magnets 132. Therefore, in the magnet unit 42, the magnetic flux is concentrated on one side, and the magnetic flux on the side closer to the stator 50 can be enhanced.

  Further, by arranging the magnetic body 133 radially outside the first magnet 131, that is, on the side opposite to the stator, it is possible to suppress partial magnetic saturation outside the first magnet 131 in the radial direction, and as a result, magnetic saturation occurs. The demagnetization of the first magnet 131 generated as a result can be suppressed. As a result, the magnetic force of the magnet unit 42 can be increased. In other words, the magnet unit 42 of the present embodiment has a configuration in which a portion of the first magnet 131 where demagnetization is likely to occur is replaced with a magnetic body 133.

  26A and 26B are diagrams specifically showing the flow of magnetic flux in the magnet unit 42. FIG. 26A shows a conventional configuration in which the magnet unit 42 does not have the magnetic body 133. FIG. 26B shows a case where the configuration of the present embodiment in which the magnet unit 42 has the magnetic body 133 is used. 26 (a) and 26 (b), the cylindrical portion 43 and the magnet unit 42 of the magnet holder 41 are linearly developed and shown. Side.

  In the configuration of FIG. 26A, the magnetic flux acting surface of the first magnet 131 and the side surface of the second magnet 132 are in contact with the inner peripheral surface of the cylindrical portion 43, respectively. The magnetic flux acting surface of the second magnet 132 is in contact with the side surface of the first magnet 131. In this case, the magnetic flux F1 entering the contact surface with the first magnet 131 through the outer path of the second magnet 132 and the magnetic flux F2 of the second magnet 132 substantially parallel to the cylindrical portion 43 pass through the cylindrical portion 43. A combined magnetic flux with the attracting magnetic flux is generated. Therefore, there is a concern that magnetic saturation may partially occur near the contact surface between the first magnet 131 and the second magnet 132 in the cylindrical portion 43.

  On the other hand, in the configuration of FIG. 26B, the magnetic body 133 is provided between the magnetic flux acting surface of the first magnet 131 and the inner peripheral surface of the cylindrical portion 43 on the opposite side of the stator 50 of the first magnet 131. Since it is provided, the magnetic body 133 allows the passage of magnetic flux. Therefore, magnetic saturation in the cylindrical portion 43 can be suppressed, and the proof strength against demagnetization is improved.

  Further, in the configuration of FIG. 26B, unlike in FIG. 26A, F2 that promotes magnetic saturation can be eliminated. Thereby, the permeance of the entire magnetic circuit can be effectively improved. With this configuration, the magnetic circuit characteristics can be maintained even under severe high-temperature conditions.

  Further, compared with the radial magnet in the conventional SPM rotor, the magnet magnetic path passing inside the magnet is longer. Therefore, the magnet permeance increases, the magnetic force can be increased, and the torque can be increased. Further, since the magnetic flux is concentrated at the center of the d-axis, the sine wave matching ratio can be increased. In particular, when the current waveform is changed to a sine wave or a trapezoidal wave by the PWM control, or a switching IC with 120-degree conduction is used, the torque can be more effectively increased.

  In the case where the stator core 52 is made of an electromagnetic steel sheet, the radial thickness of the stator core 52 may be １ ／ or larger than 径 of the radial thickness of the magnet unit 42. For example, the radial thickness of the stator core 52 is preferably equal to or more than の of the radial thickness of the first magnet 131 provided at the center of the magnetic pole in the magnet unit 42. Further, the radial thickness of the stator core 52 may be smaller than the radial thickness of the magnet unit 42. In this case, the magnetic flux of the magnet is about 1 [T], and the saturation magnetic flux density of the stator core 52 is 2 [T], so that the radial thickness of the stator core 52 is reduced by the radial thickness of the magnet unit 42. By not less than の of the above, it is possible to prevent magnetic flux leakage to the inner peripheral side of the stator core 52.

  In a magnet having a Halbach structure or a very anisotropic structure, since the magnetic path has a pseudo-arc shape, the magnetic flux can be increased in proportion to the thickness of the magnet that handles the magnetic flux in the circumferential direction. In such a configuration, it is considered that the magnetic flux flowing through the stator core 52 does not exceed the magnetic flux in the circumferential direction. That is, when an iron-based metal having a saturation magnetic flux density of 2 [T] with respect to the magnetic flux of 1 [T] of the magnet is used, if the thickness of the stator core 52 is set to half or more of the thickness of the magnet, magnetic saturation does not occur. A small and lightweight rotating electric machine can be provided. Here, since the demagnetizing field from the stator 50 acts on the magnet magnetic flux, the magnet magnetic flux is generally 0.9 [T] or less. Therefore, if the stator core has half the thickness of the magnet, its magnetic permeability can be kept suitably high.

  Hereinafter, a modified example in which a part of the above-described configuration is changed will be described.

(Modification 1)
In the above-described embodiment, the outer peripheral surface of the stator core 52 is formed into a curved surface without irregularities, and the plurality of conductive wire groups 81 are arranged at predetermined intervals on the outer peripheral surface. However, this may be changed. For example, as shown in FIG. 27, the stator core 52 includes an annular yoke 141 provided on the opposite side (lower side in the figure) to the rotor 40 on both radial sides of the stator winding 51, A projection 142 extends from the yoke 141 so as to project between the linear portions 83 adjacent in the circumferential direction. The protrusions 142 are provided at predetermined intervals on the radially outer side of the yoke 141, that is, on the rotor 40 side. Each conductor group 81 of the stator winding 51 is engaged with the protrusion 142 in the circumferential direction, and is arranged side by side in the circumferential direction while using the protrusion 142 as a positioning portion of the conductor group 81. Note that the protrusion 142 corresponds to a “member between conductive wires”.

  The projection 142 has a thickness in the radial direction from the yoke 141, in other words, as shown in FIG. 27, the projection 142 extends from the inner side surface 320 adjacent to the yoke 141 of the linear portion 83 in the radial direction of the yoke 141. The distance W to the apex is smaller than 1/2 (H1 in the figure) of the radial thickness of the linear portion 83 radially adjacent to the yoke 141 among the linear portions 83 in the radially inner and outer layers. It has a configuration. In other words, the dimension (thickness) T1 of the conductive wire group 81 (conductive member) in the radial direction of the stator winding 51 (stator core 52) (twice the thickness of the conductive wire 82, in other words, the stator core of the conductive wire group 81) The non-magnetic member (sealing member 57) may occupy three-quarters of the range (the shortest distance between the surface 320 in contact with 52 and the surface 330 of the conductor group 81 facing the rotor 40). Due to the thickness limitation of the protrusions 142, the protrusions 142 do not function as teeth between the conductive wire groups 81 (that is, the linear portions 83) that are adjacent in the circumferential direction, and no magnetic path is formed by the teeth. . The protrusions 142 may not be provided entirely between the conductor groups 81 arranged in the circumferential direction, but may be provided between at least one set of conductor groups 81 adjacent in the circumferential direction. For example, the protrusions 142 may be provided at regular intervals in a predetermined number between the conductive wire groups 81 in the circumferential direction. The shape of the protrusion 142 may be an arbitrary shape such as a rectangular shape or an arc shape.

  Further, on the outer peripheral surface of the stator core 52, a single linear portion 83 may be provided. Therefore, in a broad sense, the thickness of the projection 142 in the radial direction from the yoke 141 may be smaller than half the thickness of the straight portion 83 in the radial direction.

  In addition, assuming a virtual circle centered on the axis of the rotating shaft 11 and passing through the radial center position of the linear portion 83 radially adjacent to the yoke 141, the protrusion 142 is positioned within the range of the virtual circle. It is preferable to have a shape that protrudes from the yoke 141, in other words, a shape that does not protrude radially outward (ie, toward the rotor 40) from the virtual circle.

  According to the above configuration, the thickness of the protrusion 142 in the radial direction is limited and does not function as a tooth between the linear portions 83 adjacent in the circumferential direction. Is provided, the adjacent linear portions 83 can be brought closer to each other. Thereby, the cross-sectional area of the conductor 82a can be increased, and the heat generated due to the energization of the stator winding 51 can be reduced. In such a configuration, magnetic saturation can be eliminated by the absence of teeth, and the current flowing through the stator winding 51 can be increased. In this case, it is possible to suitably cope with an increase in the amount of heat generated with an increase in the supplied current. Further, in the stator winding 51, since the turn portion 84 is shifted in the radial direction and has an interference avoiding portion that avoids interference with another turn portion 84, the different turn portions 84 are separated from each other in the radial direction. Can be arranged. Thereby, the heat radiation of the turn portion 84 can be improved. As described above, it is possible to optimize the heat radiation performance of the stator 50.

  If the yoke 141 of the stator core 52 and the magnet unit 42 of the rotor 40 (that is, each of the magnets 91 and 92) are separated by a predetermined distance or more, the radial thickness of the protrusion 142 will be as shown in FIG. H1. Specifically, if the yoke 141 and the magnet unit 42 are separated from each other by 2 mm or more, the radial thickness of the protrusion 142 may be H1 or more in FIG. For example, when the thickness of the straight portion 83 in the radial direction exceeds 2 mm and the conductor group 81 is formed of two layers of conductors 82 inside and outside the radial direction, the straight portion 83 not adjacent to the yoke 141, That is, the protrusion 142 may be provided in a range from the yoke 141 to a half position of the second-layer conductive wire 82. In this case, if the radial thickness of the protrusion 142 is up to “H1 × 3/2”, the effect can be obtained to a considerable extent by increasing the conductor cross-sectional area in the conductor group 81.

  Further, the stator core 52 may have a configuration shown in FIG. Although the sealing member 57 is omitted in FIG. 28, the sealing member 57 may be provided. In FIG. 28, for convenience, the magnet unit 42 and the stator core 52 are shown as being linearly developed.

In the configuration of FIG. 28, the stator 50 has a protrusion 142 as a member between conductive wires between the conductive wires 82 (that is, the linear portions 83) adjacent in the circumferential direction. When the stator winding 51 is energized, the stator 50 functions magnetically together with one of the magnetic poles (N-pole or S-pole) of the magnet unit 42 and forms a part 350 extending in the circumferential direction of the stator 50. Have. Assuming that the length of the portion 350 in the circumferential direction of the stator 50 is Wn, the total width of the protrusions 142 existing in this length range Wn (that is, the total dimension of the stator 50 in the circumferential direction) is defined as Wn. Wt, the saturation magnetic flux density of the projection 142 is Bs, the circumferential width of one pole of the magnet unit 42 is Wm, and the residual magnetic flux density of the magnet unit 42 is Br.
Wt × Bs ≦ Wm × Br (1)
And a magnetic material.

  The range Wn is set to include a plurality of conductor groups 81 that are adjacent in the circumferential direction and include a plurality of conductor groups 81 whose excitation timings overlap. At this time, it is preferable to set the center of the gap 56 of the conductive wire group 81 as a reference (boundary) when setting the range Wn. For example, in the case of the configuration illustrated in FIG. 28, the fourth conductor group 81 up to the fourth from the shortest distance from the magnetic pole center of the N pole in the circumferential direction corresponds to the plurality of conductor groups 81. Then, the range Wn is set to include the four conductive wire groups 81. At this time, the end (start point and end point) of the range Wn is the center of the gap 56.

  In FIG. 28, each of the two ends of the range Wn includes a half of the projection 142, and thus the range Wn includes a total of four projections 142. Therefore, if the width of the protrusion 142 (that is, the dimension of the protrusion 142 in the circumferential direction of the stator 50, in other words, the interval between the adjacent conductor groups 81) is A, the total of the protrusions 142 included in the range Wn is assumed. The width is Wt = 1 / 2A + A + A + A + 1 / 2A = 4A.

  Specifically, in the present embodiment, the three-phase winding of the stator winding 51 is a distributed winding, and in the stator winding 51, the number of the protrusions 142, The number of gaps 56 between the conductor groups 81 is “the number of phases × Q”. Here, Q is the number of one-phase conductive wires 82 that comes into contact with stator core 52. When the conductors 82 are the conductor groups 81 stacked in the radial direction of the rotor 40, the number of conductors 82 on the inner peripheral side of the one-phase conductor group 81 can be said. In this case, when the three-phase winding of the stator winding 51 is energized in a predetermined order for each phase, the projections 142 for two phases are excited within one pole. Therefore, the total circumferential width Wt of the protrusions 142 that is excited by energization of the stator winding 51 in the range of one pole of the magnet unit 42 is equal to the circumferential width of the protrusions 142 (that is, the gap 56). Assuming that the dimension is A, “the number of excited phases × Q × A = 2 × 2 × A” is obtained.

  After the total width dimension Wt is defined in this way, the protrusions 142 of the stator core 52 are formed of a magnetic material that satisfies the relationship (1). Note that the total width dimension Wt is also a circumferential dimension of a portion where relative magnetic permeability can be larger than 1 in one pole. Further, in consideration of a margin, the total width dimension Wt may be set to the circumferential width dimension of the projection 142 at one magnetic pole. Specifically, since the number of the projections 142 for one pole of the magnet unit 42 is “the number of phases × Q”, the circumferential width dimension (total width dimension Wt) of the projections 142 for one magnetic pole is set to “ The number of phases × Q × A = 3 × 2 × A = 6A ”.

  The term “distributed winding” used herein refers to a period of one pole pair of magnetic poles (N pole and S pole) and one pole pair of the stator winding 51. The one pole pair of the stator winding 51 here includes two straight portions 83 and a turn portion 84 in which currents flow in opposite directions and are electrically connected by a turn portion 84. If the above conditions are satisfied, even a short-pitch winding (Short Pitch Winding) is regarded as an equivalent of a distributed winding of a full-pitch winding.

  Next, an example of concentrated winding will be described. The term “concentrated winding” as used herein means that the width of one pole pair of magnetic poles is different from the width of one pole pair of the stator winding 51. As an example of concentrated winding, three conductor groups 81 for one magnetic pole pair, three conductor groups 81 for two magnetic pole pairs, nine conductor groups 81 for four magnetic pole pairs, and 5 There is one in which the conductor group 81 has nine relations to one magnetic pole pair.

  Here, when the stator windings 51 are concentrated windings, when the three-phase windings of the stator windings 51 are energized in a predetermined order, the stator windings 51 for two phases are excited. As a result, the projections 142 for two phases are excited. Therefore, in the range of one pole of the magnet unit 42, the circumferential width Wt of the protrusion 142 that is excited when the stator winding 51 is energized is “A × 2”. After the width Wt is defined in this manner, the protrusion 142 is formed of a magnetic material satisfying the relationship (1). In the case of the concentrated winding described above, A is the sum of the widths of the protrusions 142 in the circumferential direction of the stator 50 in the region surrounded by the conductor group 81 of the same phase. Wm in the concentrated winding is equivalent to “the entire circumference of the surface of the magnet unit 42 facing the air gap” × “the number of phases” ÷ “the number of dispersions of the conductive wire group 81”.

  Incidentally, magnets having a BH product of 20 [MGOe (kJ / m ^ 3)] or more, such as neodymium magnets, samarium cobalt magnets, and ferrite magnets, have Bd = 1.0 or more [T], and iron has Br = 2.0 or more [T]. ]. Therefore, as the high-output motor, the protrusion 142 in the stator core 52 may be a magnetic material that satisfies the relationship of Wt <１ ／ × Wm.

  When the conductor 82 has the outer coating 182 as described later, the conductor 82 may be arranged in the circumferential direction of the stator core 52 such that the outer coating 182 between the conductors 82 contacts each other. In this case, Wt can be regarded as 0 or the thickness of the outer layer coating 182 of the two conducting wires 82 in contact with each other.

  27 and 28 have a configuration in which the inter-wire member (projection 142) is unreasonably small with respect to the magnetic flux on the rotor 40 side. The rotor 40 is a flat surface magnet type rotor having low inductance and does not have saliency in terms of magnetoresistance. In such a configuration, the inductance of the stator 50 can be reduced, and the occurrence of magnetic flux distortion due to the shift of the switching timing of the stator winding 51 is suppressed, and thus the electrolytic corrosion of the bearings 21 and 22 is suppressed. .

(Modification 2)
The following configuration can be adopted as the stator 50 using the inter-conductor member satisfying the relationship of the above equation (1). In FIG. 29, a tooth-shaped portion 143 is provided on the outer peripheral surface side (the upper surface side in the figure) of the stator core 52 as a member between conductive wires. The teeth 143 are provided at predetermined intervals in the circumferential direction so as to protrude from the yoke 141, and have the same thickness dimension as the conductor group 81 in the radial direction. The side surface of the toothed portion 143 is in contact with each conductor 82 of the conductor group 81. However, a gap may be provided between the tooth-shaped portion 143 and each conductive wire 82.

  The tooth-shaped portion 143 has a limitation on the width dimension in the circumferential direction, and is provided with pole teeth (stator teeth) which are unreasonably thin with respect to the amount of magnets. With such a configuration, the tooth-shaped portion 143 is surely saturated by the magnetic flux at 1.8 T or more, and the inductance can be reduced due to a decrease in permeance.

Here, in the magnet unit 42, assuming that the surface area per pole of the magnetic flux acting surface on the stator side per pole is Sm and the residual magnetic flux density of the magnet unit 42 is Br, the magnetic flux on the magnet unit side is, for example, “Sm × Br”. Become. Also, the surface area of each tooth 143 on the rotor side is St, the number of conductors 82 per phase is m, and the tooth windings 143 for two phases are excited within one pole by the current flowing through the stator winding 51. Then, the magnetic flux on the stator side is, for example, “St × m × 2 × Bs”. in this case,
St × m × 2 × Bs <Sm × Br (2)
The inductance is reduced by limiting the size of the tooth-shaped portion 143 so that the relationship of

When the magnet unit 42 and the toothed part 143 have the same axial dimension, the circumferential width of one pole of the magnet unit 42 is Wm, and the circumferential width of the toothed part 143 is Wst. Then, the above equation (2) is replaced by an equation (3).
Wst × m × 2 × Bs <Wm × Br (3)
More specifically, assuming that Bs = 2T, Br = 1T, and m = 2, the above equation (3) has a relationship of “Wst <Wm / 8”. In this case, the inductance is reduced by setting the width Wst of the toothed portion 143 to be smaller than １ ／ of the width Wm of one pole of the magnet unit 42. If the number m is 1, the width Wst of the toothed portion 143 may be smaller than １ ／ of the width Wm of one pole of the magnet unit 42.

  In the above equation (3), “Wst × m × 2” is the width in the circumferential direction of the tooth-shaped portion 143 that is excited when the stator winding 51 is energized in the range of one pole of the magnet unit 42. Equivalent to.

  In the configuration of FIG. 29, similarly to the configurations of FIGS. 27 and 28 described above, a configuration is provided in which the inter-wire member (tooth-shaped portion 143) is unreasonably small with respect to the magnet magnetic flux on the rotor 40 side. In such a configuration, the inductance of the stator 50 can be reduced, and the occurrence of magnetic flux distortion due to the shift of the switching timing of the stator winding 51 is suppressed, and thus the electrolytic corrosion of the bearings 21 and 22 is suppressed. .

(Modification 3)
In the above-described embodiment, the sealing member 57 that covers the stator windings 51 is provided in a range that includes all of the conductor groups 81 outside the stator core 52 in the radial direction, that is, the thickness in the radial direction is equal to the diameter of each conductor group 81. Although the thickness is set to be larger than the thickness in the direction, the thickness may be changed. For example, as shown in FIG. 30, the sealing member 57 is provided so that a part of the conductive wire 82 protrudes. More specifically, the sealing member 57 is configured to be provided in a state in which a part of the conductive wire 82 that is the radially outermost in the conductive wire group 81 is exposed to the radially outer side, that is, to the stator 50 side. In this case, the thickness of the sealing member 57 in the radial direction is preferably equal to or smaller than the thickness of the conductor group 81 in the radial direction.

(Modification 4)
As shown in FIG. 31, in the stator 50, the configuration may be such that each conductive wire group 81 is not sealed by the sealing member 57. That is, the configuration is such that the sealing member 57 that covers the stator winding 51 is not used. In this case, there is no gap between the conductors between the conductor groups 81 arranged in the circumferential direction, and there is a gap. In short, the configuration is such that no inter-conductor member is provided between the conductor groups 81 arranged in the circumferential direction. Note that Bs = 0 may be regarded as air as a non-magnetic material or an equivalent of the non-magnetic material, and air may be arranged in this gap.

(Modification 5)
When the inter-wire member of the stator 50 is made of a non-magnetic material, a material other than resin can be used as the non-magnetic material. For example, a metallic nonmagnetic material such as SUS304, which is an austenitic stainless steel, may be used.

(Modification 6)
The stator 50 may not have the stator core 52. In this case, the stator 50 is constituted by the stator winding 51 shown in FIG. In the stator 50 having no stator core 52, the stator winding 51 may be sealed with a sealing material. Alternatively, the stator 50 may include an annular winding holding portion made of a nonmagnetic material such as a synthetic resin, instead of the stator core 52 made of a soft magnetic material.

(Modification 7)
In the first embodiment, the plurality of magnets 91 and 92 arranged in the circumferential direction are used as the magnet unit 42 of the rotor 40. However, this is changed, and the magnet unit 42 is an annular permanent magnet. A configuration using a magnet may be used. Specifically, as shown in FIG. 32, an annular magnet 95 is fixed radially inside the cylindrical portion 43 of the magnet holder 41. The annular magnet 95 is provided with a plurality of magnetic poles having alternating polarities in the circumferential direction, and the magnet is integrally formed on both the d-axis and the q-axis. The annular magnet 95 is formed with an arc-shaped magnet magnetic path in which the direction of orientation is radial in the d-axis of each magnetic pole and circumferential in the q-axis between the magnetic poles.

  In the ring magnet 95, the easy axis of magnetization is oriented parallel to or nearly parallel to the d axis in a portion near the d axis, and the easy axis of magnetization is orthogonal to the q axis or in the q axis in a portion near the q axis. It is sufficient that the orientation is made so as to form an arc-shaped magnet magnetic path that is nearly orthogonal.

(Modification 8)
In this modification, a part of the control method of the control device 110 is changed. In the present modification, mainly, differences from the configuration described in the first embodiment will be described.

  First, the processing in the operation signal generators 116 and 126 shown in FIG. 20 and the processing in the operation signal generators 130a and 130b shown in FIG. 21 will be described using FIG. The processing in each of the operation signal generators 116, 126, 130a, and 130b is basically the same. Therefore, hereinafter, the processing of the operation signal generation unit 116 will be described as an example.

  The operation signal generator 116 includes a carrier generator 116a and U, V, and W phase comparators 116bU, 116bV, and 116bW. In the present embodiment, the carrier generator 116a generates and outputs a triangular wave signal as the carrier signal SigC.

  The U, V, and W phase comparators 116bU, 116bV, and 116bW receive the carrier signal SigC generated by the carrier generation unit 116a and the U, V, and W phase command voltages calculated by the three-phase conversion unit 115. You. The U-, V-, and W-phase command voltages are, for example, sinusoidal waveforms, and are out of phase by 120 ° in electrical angle.

  The U, V, and W phase comparators 116bU, 116bV, and 116bW control the U, V, and W phase command voltages and the carrier signal SigC by PWM (pulse width modulation) control based on the magnitude comparison between the U, V, and W phase comparators. , V, and W-phase operation signals for the switches Sp and Sn of the upper arm and the lower arm. Specifically, the operation signal generation unit 116 performs each of the U, V, and W phases by PWM control based on a magnitude comparison between a signal obtained by standardizing the U, V, and W phase command voltages by the power supply voltage and a carrier signal. An operation signal for the switches Sp and Sn is generated. The driver 117 turns on and off the U, V, and W phase switches Sp and Sn in the first inverter 101 based on the operation signal generated by the operation signal generation unit 116.

  The control device 110 performs a process of changing the carrier frequency fc of the carrier signal SigC, that is, the switching frequency of each of the switches Sp and Sn. The carrier frequency fc is set high in a low torque region or a high rotation region of the rotating electric machine 10, and set low in a high torque region of the rotating electric machine 10. This setting is made in order to suppress a decrease in the controllability of the current flowing through each phase winding.

  That is, as the stator 50 becomes coreless, the inductance of the stator 50 can be reduced. Here, when the inductance decreases, the electrical time constant of the rotating electric machine 10 decreases. As a result, there is a concern that the ripple of the current flowing through each phase winding increases, the controllability of the current flowing through the winding decreases, and current control diverges. The effect of the decrease in controllability may be more remarkable when the current flowing through the winding (for example, the effective value of the current) is included in the low current region than in the high current region. In order to address this problem, in the present modification, control device 110 changes carrier frequency fc.

  The process of changing the carrier frequency fc will be described with reference to FIG. This process is repeatedly executed by the control device 110, for example, at a predetermined control cycle, as the process of the operation signal generation unit 116.

  In step S10, it is determined whether the current flowing through each phase winding 51a is included in the low current region. This process is a process for determining that the current torque of the rotating electric machine 10 is in the low torque region. For example, the following first and second methods can be used as a method for determining whether or not the pixel is included in the low current region.

<First method>
Based on the d-axis current and the q-axis current converted by the dq conversion unit 112, an estimated torque value of the rotating electric machine 10 is calculated. When it is determined that the calculated torque estimated value is less than the torque threshold, it is determined that the current flowing through the winding 51a is included in the low current region, and when it is determined that the torque estimated value is equal to or larger than the torque threshold. , Is included in the high current region. Here, the torque threshold may be set to, for example, １ ／ of the starting torque (also referred to as a constraint torque) of the rotating electric machine 10.

<Second method>
When it is determined that the rotation angle of the rotor 40 detected by the angle detector is equal to or greater than the speed threshold, it is determined that the current flowing through the winding 51a is included in the low current region, that is, the high rotation region. Here, the speed threshold may be set to, for example, the rotation speed when the maximum torque of the rotating electric machine 10 is the torque threshold.

  If a negative determination is made in step S10, it is determined that the current is in the high current region, and the process proceeds to step S11. In step S11, the carrier frequency fc is set to the first frequency fL.

  If an affirmative determination is made in step S10, the process proceeds to step S12, where the carrier frequency fc is set to a second frequency fH higher than the first frequency fL.

  According to the above-described modified example, the carrier frequency fc is set higher when the current flowing through each phase winding is included in the low current region than in the high current region. Therefore, in the low current region, the switching frequency of the switches Sp and Sn can be increased, and an increase in current ripple can be suppressed. Thereby, a decrease in current controllability can be suppressed.

  On the other hand, when the current flowing through each phase winding is included in the high current region, the carrier frequency fc is set lower than when it is included in the low current region. In the high current region, the amplitude of the current flowing through the winding is larger than in the low current region, so that the increase in the current ripple due to the lower inductance has little effect on the current controllability. Therefore, the carrier frequency fc can be set lower in the high current region than in the low current region, and the switching loss of each of the inverters 101 and 102 can be reduced.

  In this modification, the following embodiments can be implemented.

  In the case where the carrier frequency fc is set to the first frequency fL, when the affirmative determination is made in step S10 of FIG. 34, the carrier frequency fc is gradually changed from the first frequency fL to the second frequency fH. Is also good.

  When the carrier frequency fc is set to the second frequency fH and a negative determination is made in step S10, the carrier frequency fc may be gradually changed from the second frequency fH to the first frequency fL. .

  A switch operation signal may be generated by space vector modulation (SVM) control instead of PWM control. Even in this case, the change of the switching frequency described above can be applied.

(Modification 9)
In each of the above embodiments, two pairs of conductors of each phase constituting the conductor group 81 are connected in parallel as shown in FIG. FIG. 35A is a diagram illustrating electrical connection between first and second conductive wires 88a and 88b, which are two pairs of conductive wires. Here, instead of the configuration shown in FIG. 35A, the first and second conductive wires 88a and 88b may be connected in series as shown in FIG. 35B.

  Further, three or more pairs of multilayer conductors may be stacked in the radial direction. FIG. 36 shows a configuration in which four pairs of first to fourth conductive wires 88a to 88d are stacked. The first to fourth conductive wires 88a to 88d are arranged in the radial direction in the order of the first, second, third, and fourth conductive wires 88a, 88b, 88c, and 88d from the side closer to the stator core 52. .

  Here, as shown in FIG. 35 (c), the third and fourth conductors 88c and 88d are connected in parallel, a first conductor 88a is connected to one end of the parallel connection body, and a second conductor is connected to the other end. 88b may be connected. When the connection is made in parallel, the current density of the conductive wires connected in parallel can be reduced, and the heat generation during energization can be suppressed. Therefore, in a configuration in which the cylindrical stator winding is assembled to the housing (unit base 61) in which the cooling water passage 74 is formed, the first and second conductive wires 88a and 88b that are not connected in parallel abut on the unit base 61. The third and fourth conductive wires 88c and 88d arranged on the stator core 52 side and connected in parallel are arranged on the side opposite to the stator core side. Thereby, the cooling performance of each of the conductors 88a to 88d in the multilayer conductor structure can be equalized.

  Note that the thickness of the conductive wire group 81 including the first to fourth conductive wires 88a to 88d in the radial direction may be smaller than the circumferential width of one phase in one magnetic pole.

(Modification 10)
The rotating electric machine 10 may have an inner rotor structure (adduction structure). In this case, for example, the stator 50 may be provided radially outside the housing 30 and the rotor 40 may be provided radially inside the housing 30. Further, the inverter unit 60 may be provided on one or both of the axial ends of the stator 50 and the rotor 40. FIG. 37 is a cross-sectional view of the rotor 40 and the stator 50, and FIG. 38 is an enlarged view of a part of the rotor 40 and the stator 50 shown in FIG.

The configuration shown in FIGS. 37 and 38 based on the inner rotor structure is different from the configuration shown in FIGS. 8 and 9 based on the outer rotor structure in that the rotor 40 and the stator 50 are reversed inside and outside the radial direction. Except for, the configuration is the same. In brief, the stator 50 has a stator winding 51 having a flat conductive wire structure and a stator core 52 having no teeth. The stator winding 51 is mounted radially inside the stator core 52. The stator core 52 has any one of the following configurations, similarly to the case of the outer rotor structure.
(A) In the stator 50, an inter-conductor member is provided between the respective conductor portions in the circumferential direction, and as the inter-conductor member, the circumferential width of the inter-conductor member at one magnetic pole is Wt, and the saturation of the inter-conductor member is achieved. When the magnetic flux density is Bs, the circumferential width of the magnet unit at one magnetic pole is Wm, and the residual magnetic flux density of the magnet unit is Br, a magnetic material that satisfies Wt × Bs ≦ Wm × Br is used.
(B) In the stator 50, an inter-conductor member is provided between the conductor portions in the circumferential direction, and a non-magnetic material is used as the inter-conductor member.
(C) The stator 50 has a configuration in which no inter-conductor member is provided between the respective conductor portions in the circumferential direction.

  The same applies to the magnets 91 and 92 of the magnet unit 42. That is, the magnet units 42 and 91 are oriented such that the direction of the easy axis of magnetization is parallel to the d-axis on the d-axis side, which is the center of the magnetic pole, compared to the q-axis side, which is the boundary of the magnetic poles. It is configured using Details such as the magnetization direction of each of the magnets 91 and 92 are as described above. It is also possible to use an annular magnet 95 (see FIG. 32) in the magnet unit 42.

  FIG. 39 is a longitudinal sectional view of the rotating electric machine 10 in the case of the inner rotor type, which corresponds to FIG. 2 described above. The differences from the configuration of FIG. 2 will be briefly described. In FIG. 39, an annular stator 50 is fixed inside a housing 30, and a rotor 40 is rotatably provided inside the stator 50 with a predetermined air gap interposed therebetween. As in FIG. 2, each of the bearings 21 and 22 is disposed so as to be biased toward one of the axial directions with respect to the axial center of the rotor 40, whereby the rotor 40 is cantilevered. I have. The inverter unit 60 is provided inside the magnet holder 41 of the rotor 40.

  FIG. 40 shows another configuration as the rotating electric machine 10 having the inner rotor structure. In FIG. 40, a rotating shaft 11 is rotatably supported by bearings 21 and 22 in a housing 30, and a rotor 40 is fixed to the rotating shaft 11. As in the configuration shown in FIG. 2 and the like, each of the bearings 21 and 22 is arranged so as to be biased toward one of the axial directions with respect to the axial center of the rotor 40. The rotor 40 has a magnet holder 41 and a magnet unit 42.

  The rotating electric machine 10 of FIG. 40 is different from the rotating electric machine 10 of FIG. 39 in that the inverter unit 60 is not provided inside the rotor 40 in the radial direction. The magnet holder 41 is connected to the rotating shaft 11 at a position radially inside the magnet unit 42. Further, the stator 50 has a stator winding 51 and a stator core 52 and is attached to the housing 30.

(Modification 11)
Another configuration as a rotating electric machine having an inner rotor structure will be described below. FIG. 41 is an exploded perspective view of the rotating electric machine 200, and FIG. 42 is a side sectional view of the rotating electric machine 200. In this case, the vertical direction is shown based on the states of FIGS. 41 and 42.

  As shown in FIG. 41 and FIG. 42, the rotating electric machine 200 is rotatably disposed inside the stator core 201 having an annular stator core 201 and a multi-phase stator winding 202, and a stator 203. And a rotator 204. The stator 203 corresponds to an armature, and the rotor 204 corresponds to a field element. The stator core 201 is formed by laminating a number of silicon steel plates, and a stator winding 202 is attached to the stator core 201. Although not shown, the rotor 204 has a rotor core and a plurality of permanent magnets as magnet units. A plurality of magnet insertion holes are provided in the rotor core at equal intervals in the circumferential direction. In each of the magnet insertion holes, a permanent magnet that is magnetized so that the magnetization direction changes alternately for each adjacent magnetic pole is mounted. The permanent magnet of the magnet unit may have a Halbach array as described with reference to FIG. 25 or a configuration similar thereto. Alternatively, the permanent magnet of the magnet unit has a pole whose orientation direction (magnetization direction) extends in an arc shape between the d axis, which is the center of the magnetic pole, and the q axis, which is the boundary of the magnetic pole, as described in FIGS. It is preferable to have anisotropic characteristics.

Here, the stator 203 may have any of the following configurations.
(A) In the stator 203, an inter-conductor member is provided between the respective conductor portions in the circumferential direction, and as the inter-conductor member, the circumferential width of the inter-conductor member at one magnetic pole is Wt, and the saturation of the inter-conductor member is achieved. When the magnetic flux density is Bs, the circumferential width of the magnet unit at one magnetic pole is Wm, and the residual magnetic flux density of the magnet unit is Br, a magnetic material that satisfies Wt × Bs ≦ Wm × Br is used.
(B) In the stator 203, an inter-conductor member is provided between the conductor portions in the circumferential direction, and a non-magnetic material is used as the inter-conductor member.
(C) The stator 203 has a configuration in which no inter-conductor member is provided between the respective conductor portions in the circumferential direction.

  In the rotor 204, the magnet unit was oriented such that the direction of the easy axis of magnetization was parallel to the d-axis on the d-axis side, which is the center of the magnetic pole, compared to the q-axis side, which is the boundary of the magnetic poles. It is configured using a plurality of magnets.

  An annular inverter case 211 is provided at one axial end of the rotating electric machine 200. Inverter case 211 is arranged such that the lower surface of the case is in contact with the upper surface of stator core 201. In an inverter case 211, a plurality of power modules 212 constituting an inverter circuit, a smoothing capacitor 213 for suppressing pulsation (ripple) of voltage and current generated by a switching operation of a semiconductor switching element, and a control board 214 having a control unit , A current sensor 215 for detecting a phase current, and a resolver stator 216 that is a rotation speed sensor of the rotor 204. The power module 212 has an IGBT or a diode that is a semiconductor switching element.

  A power connector 217 connected to a DC circuit of a battery mounted on the vehicle, and a signal connector 218 used for transferring various signals between the rotating electric machine 200 and the vehicle-side control device are provided on the periphery of the inverter case 211. Is provided. The inverter case 211 is covered with a top cover 219. DC power from the vehicle-mounted battery is input via the power connector 217, converted into AC by switching of the power module 212, and sent to the stator winding 202 of each phase.

  A bearing unit 221 for rotatably holding the rotating shaft of the rotor 204 and an annular rear case 222 for accommodating the bearing unit 221 are provided on the opposite sides of the stator core 201 in the axial direction opposite to the inverter case 211. Is provided. The bearing unit 221 has, for example, a pair of bearings, and is arranged so as to be deviated to one side in the axial direction with respect to the axial center of the rotor 204. However, a configuration in which a plurality of bearings of the bearing unit 221 are provided separately on both sides in the axial direction of the stator core 201 and the rotating shaft is supported at both ends by the respective bearings may be adopted. The rotating electrical machine 200 is mounted on the vehicle side by fixing the rear case 222 to the mounting portion such as a gear case or a transmission of the vehicle by bolting.

  In the inverter case 211, a cooling channel 211a for flowing a refrigerant is formed. The cooling channel 211 a is formed by closing a space recessed annularly from the lower surface of the inverter case 211 with the upper surface of the stator core 201. The cooling passage 211a is formed so as to surround the coil end of the stator winding 202. The module case 212a of the power module 212 is inserted into the cooling channel 211a. A cooling channel 222 a is also formed in the rear case 222 so as to surround the coil end of the stator winding 202. The cooling channel 222 a is formed by closing a space recessed annularly from the upper surface of the rear case 222 with the lower surface of the stator core 201.

(Modification 12)
The configuration embodied in the rotating field type rotary electric machine has been described above, but it is also possible to change the configuration and embodied in a rotary armature type rotary electric machine. FIG. 43 shows a configuration of a rotary armature type rotary electric machine 230.

  43, a bearing 232 is fixed to each of the housings 231a and 231b, and the rotating shaft 233 is rotatably supported by the bearing 232. The bearing 232 is, for example, an oil-impregnated bearing made of a porous metal containing oil. A rotor 234 as an armature is fixed to the rotation shaft 233. The rotor 234 has a rotor core 235 and a multi-phase rotor winding 236 fixed to an outer peripheral portion thereof. In the rotor 234, the rotor core 235 has a slotless structure, and the rotor winding 236 has a flat conductor structure. That is, the rotor winding 236 has a flat structure in which the region for each phase is longer in the circumferential direction than in the radial direction.

  A stator 237 as a field element is provided radially outside the rotor 234. The stator 237 has a stator core 238 fixed to the housing 231a, and a magnet unit 239 fixed to the inner peripheral side of the stator core 238. The magnet unit 239 includes a plurality of magnetic poles having polarities alternated in the circumferential direction. Like the magnet unit 42 described above, the magnet unit 239 has a magnetic pole boundary q on the d-axis side that is the center of the magnetic pole. The orientation is made such that the direction of the easy axis of magnetization is parallel to the d-axis as compared to the axis side. The magnet unit 239 has an oriented sintered neodymium magnet, and its intrinsic coercive force is 400 [kA / m] or more and the residual magnetic flux density is 1.0 [T] or more.

  The rotating electric machine 230 of this example is a brushless coreless motor having two poles and three coils, the rotor winding 236 is divided into three, and the magnet unit 239 has two poles. The number of poles and the number of coils of the brushed motor varies depending on the application, such as 2: 3, 4:10, and 4:21.

  A commutator 241 is fixed to the rotating shaft 233, and a plurality of brushes 242 are arranged radially outside. The commutator 241 is electrically connected to the rotor winding 236 via a conductor 243 embedded in the rotating shaft 233. The direct current flows into and out of the rotor winding 236 through the commutator 241, the brush 242, and the conducting wire 243. The commutator 241 is appropriately divided in the circumferential direction according to the number of phases of the rotor winding 236. The brush 242 may be directly connected to a DC power supply such as a storage battery via electrical wiring, or may be connected to a DC power supply via a terminal block or the like.

  The rotating shaft 233 is provided with a resin washer 244 as a sealing material between the bearing 232 and the commutator 241. The resin washer 244 suppresses oil that has oozed from the bearing 232 that is an oil-impregnated bearing from flowing out to the commutator 241 side.

(Modification 13)
In the stator winding 51 of the rotating electric machine 10, each of the conductors 82 may be configured to have a plurality of insulating coatings inside and outside. For example, a plurality of conductive wires (element wires) with an insulating coating may be bundled into one and covered with an outer coating to form the conductive wire 82. In this case, the insulating coating of the element wire forms the inner insulating coating, and the outer coating forms the outer insulating coating. In particular, it is preferable that the insulating ability of the outer insulating coat among the plurality of insulating coats in the conductive wire 82 be higher than the insulating ability of the inner insulating coat. Specifically, the thickness of the outer insulating coating is made larger than the thickness of the inner insulating coating. For example, the thickness of the outer insulating coating is 100 μm, and the thickness of the inner insulating coating is 40 μm. Alternatively, a material having a lower dielectric constant than the inner insulating film may be used as the outer insulating film. At least one of these may be applied. Note that the strands may be configured as an aggregate of a plurality of conductive materials.

  By strengthening the insulation of the outermost layer of the conductor 82 as described above, it becomes suitable for use in a high-voltage vehicle system. In addition, it is possible to appropriately drive the rotating electric machine 10 even at a high altitude where the atmospheric pressure is low.

(Modification 14)
In the conductive wire 82 having a plurality of inner and outer insulating coatings, the outer insulating coating and the inner insulating coating may have a configuration in which at least one of the coefficient of linear expansion (linear expansion coefficient) and the adhesive strength is different. FIG. 44 shows the configuration of the conductor 82 in this modification.

  In FIG. 44, a conductor 82 includes a plurality of (four in the figure) strands 181, a resin outer layer coating 182 (outer insulating coating) surrounding the plurality of strands 181, and each element in the outer layer coating 182. And an intermediate layer 183 (intermediate insulating film) filled around the line 181. The strand 181 has a conductive portion 181a made of a copper material and a conductor film 181b (an inner insulating film) made of an insulating material. When viewed as a stator winding, the outer layers 182 insulate the phases. Note that the strand 181 may be configured as an aggregate of a plurality of conductive materials.

  The intermediate layer 183 has a higher linear expansion coefficient than the conductor coating 181b of the strand 181 and has a lower linear expansion coefficient than the outer coating 182. That is, in the conductor 82, the coefficient of linear expansion is higher toward the outside. Generally, the outer layer coating 182 has a higher linear expansion coefficient than the conductor coating 181b, but by providing an intermediate layer 183 having an intermediate linear expansion coefficient between them, the intermediate layer 183 functions as a cushion material. In addition, simultaneous cracking on the outer layer side and the inner layer side can be prevented.

  In the conductive wire 82, the conductive portion 181a and the conductive film 181b are bonded to the wire 181 and the conductive film 181b and the intermediate layer 183, and the intermediate layer 183 and the outer layer film 182 are bonded to each other. In the figure, the bonding strength is weaker toward the outside of the conducting wire 82. That is, the adhesive strength between the conductive portion 181a and the conductive coating 181b is lower than the adhesive strength between the conductive coating 181b and the intermediate layer 183, and the adhesive strength between the intermediate layer 183 and the outer coating 182. Further, comparing the adhesive strength between the conductor coating 181b and the intermediate layer 183 and the adhesive strength between the intermediate layer 183 and the outer coating 182, the latter (outer side) is preferably weaker or equivalent. It should be noted that the magnitude of the adhesive strength between the coatings can be grasped, for example, from the tensile strength and the like required when the two coatings are peeled off. By setting the bonding strength of the conductive wire 82 as described above, it is possible to suppress the occurrence of cracks (co-cracking) on both the inner layer side and the outer layer side even if an internal / external temperature difference occurs due to heat generation or cooling. .

  Here, heat generation and temperature change of the rotating electric machine mainly occur as copper loss generated from the conductive portion 181a of the wire 181 and iron loss generated from within the iron core. The conductive layer 181a is transmitted from the outside of the conductive portion 181a or the conductive wire 82, and the intermediate layer 183 does not necessarily have a heat source. In this case, since the intermediate layer 183 has an adhesive force that can serve as a cushion for both, simultaneous cracking can be prevented. Therefore, suitable use is possible even when used in a field having a high withstand voltage or a large temperature change such as a vehicle application.

  The following is supplemented. The strand 181 may be, for example, an enameled wire, and in such a case, has a resin coating layer (conductor coating 181b) of PA, PI, PAI or the like. Further, it is desirable that the outer layer coating 182 outside the wire 181 be made of the same PA, PI, PAI or the like, and be thick. Thereby, the destruction of the coating film due to the difference in linear expansion coefficient is suppressed. The outer layer coating 182 has a dielectric constant such as PPS, PEEK, fluorine, polycarbonate, silicon, epoxy, polyethylene naphthalate, or LCP, which is different from the corresponding material such as PA, PI, PAI by thickening the corresponding material. It is also desirable to use a material smaller than PI and PAI in order to increase the conductor density of the rotating machine. With these resins, even if they are thinner than the PI and PAI coatings equivalent to the conductor coating 181b or have the same thickness as the conductor coating 181b, their insulating ability can be increased, thereby increasing the occupancy of the conductive portion. Can be increased. Generally, the resin has better insulation than the insulating coating of the enameled wire. Naturally, there is an example in which the dielectric constant is deteriorated depending on the molding state or the mixture. Above all, PPS and PEEK generally have a higher coefficient of linear expansion than the enamel coating, but are smaller than other resins, and thus are suitable as the outer coating of the second layer.

  The adhesive strength between the two types of coatings (intermediate insulating coating and outer insulating coating) on the outside of the wire 181 and the enamel coating on the wire 181 is determined by the adhesive strength between the copper wire and the enamel coating on the wire 181. It is desirable that it be weaker. This suppresses a phenomenon in which the enamel coating and the two types of coatings are destroyed at a time.

  When a water-cooled structure, a liquid-cooled structure, or an air-cooled structure is added to the stator, it is basically considered that a thermal stress or an impact stress is applied first to the outer layer coating 182. However, even when the insulating layer of the strand 181 and the two types of coatings are made of different resins, the thermal stress and the impact stress can be reduced by providing a portion where the coatings are not bonded. That is, the insulating structure is formed by providing a gap between the element wire (enameled wire) and the void, and arranging fluorine, polycarbonate, silicon, epoxy, polyethylene naphthalate, and LCP. In this case, it is desirable to bond the outer layer coating and the inner layer coating using an adhesive made of epoxy or the like having a low dielectric constant and a low linear expansion coefficient. By doing so, it is possible to suppress not only the mechanical strength but also the destruction of the coating due to friction caused by the vibration of the conductive portion due to vibration or the destruction of the outer coating due to the difference in linear expansion coefficient.

  The outermost layer fixed as a final step around the stator winding, which is responsible for mechanical strength, fixing, and the like, for the conductor 82 having the above-described configuration, is formed of epoxy, PPS, PEEK, LCP, or the like. It is preferable to use a resin having properties such as a dielectric constant and a linear expansion coefficient close to those of an enamel coating.

  Generally, resin potting using urethane or silicon is generally performed. However, the resin has a coefficient of linear expansion that is nearly twice as large as that of other resins, and generates thermal stress capable of shearing the resin. Therefore, it is not suitable for use at 60 V or higher where strict insulation regulations are used internationally. In this regard, according to the final insulation process that is easily made by injection molding or the like using epoxy, PPS, PEEK, LCP, or the like, the above-described requirements can be achieved.

  Modifications other than the above are listed below.

  The radial distance DM between the armature side surface of the magnet unit 42 in the radial direction and the axis of the rotor may be 50 mm or more. Specifically, for example, in the radial direction between the radially inner surface of the magnet unit 42 (specifically, the first and second magnets 91 and 92) shown in FIG. The distance DM may be set to 50 mm or more.

  As a rotary electric machine having a slotless structure, a small-sized electric machine whose output is used for a model whose output is several tens W to several hundreds W is known. In addition, the present inventor has not grasped a case where a slotless structure is employed in a large-scale rotating electric machine for industrial use generally exceeding 10 kW. The inventors of the present application have examined the reason.

  In recent years, the mainstream rotating electric machines are roughly classified into the following four types. The rotating electric machines are a brush motor, a cage induction motor, a permanent magnet synchronous motor, and a reluctance motor.

  An excitation current is supplied to the motor with a brush via a brush. For this reason, in the case of a motor with a brush of a large machine, the brush becomes large or the maintenance becomes complicated. As a result, with the remarkable development of semiconductor technology, there has been a history of replacement with brushless motors such as induction motors. On the other hand, in the world of small motors, coreless motors are also supplied to many people due to the advantages of low inertia and economy.

  In a cage-type induction motor, a magnetic field generated by a stator winding on a primary side is received by an iron core of a rotor on a secondary side, and an induced current is intensively applied to a cage-type conductor to form a reaction magnetic field. This is the principle of generating torque. For this reason, from the viewpoint of miniaturization and high efficiency of the device, it is not always advisable to eliminate the iron core on both the stator side and the rotor side.

  The reluctance motor is a motor that utilizes the reluctance change of the iron core, and it is not desirable to eliminate the iron core in principle.

  In recent years, IPMs (i.e., embedded magnet type rotors) have become mainstream in permanent magnet type synchronous motors, and especially in large machines, IPMs are often used unless there are special circumstances.

  The IPM has a characteristic having both a magnet torque and a reluctance torque, and is operated while the ratio of those torques is appropriately adjusted by inverter control. Therefore, the IPM is a small-sized motor having excellent controllability.

  According to the analysis of the inventor of the present application, the torque of the rotor surface that generates the magnet torque and the reluctance torque is determined by calculating the distance DM in the radial direction between the armature side surface of the magnet unit in the radial direction and the axis of the rotor, that is, FIG. 45 shows the radius of the stator core of a general inner rotor taken on the horizontal axis.

  As shown in the following equation (eq1), the potential of the magnet torque is determined by the strength of the magnetic field generated by the permanent magnet, whereas the reluctance torque is expressed by inductance, particularly q, as shown in the following equation (eq2). The magnitude of the shaft inductance determines its potential.

Magnet torque = k · Ψ · Iq (eq1)
Reluctance torque = k · (Lq−Ld) · Iq · Id (eq2)
Here, the magnetic field strength of the permanent magnet and the magnitude of the inductance of the winding were compared by DM. The magnetic field intensity generated by the permanent magnet, that is, the amount of magnetic flux Ψ is proportional to the total area of the permanent magnet on the surface facing the stator. In the case of a cylindrical rotor, it is the surface area of the cylinder. Strictly speaking, since there are an N pole and an S pole, it is proportional to the area occupied by half of the cylindrical surface. The surface area of a cylinder is proportional to the radius of the cylinder and the length of the cylinder. That is, if the length of the cylinder is constant, it is proportional to the radius of the cylinder.

  On the other hand, although the inductance Lq of the winding depends on the shape of the iron core, the sensitivity is low. Rather, the inductance Lq is proportional to the square of the number of turns of the stator winding. When μ is the magnetic permeability of the magnetic circuit, N is the number of turns, S is the cross-sectional area of the magnetic circuit, and δ is the effective length of the magnetic circuit, the inductance L = μ · N ＾ 2 × S / δ. Since the number of windings depends on the size of the winding space, in the case of a cylindrical motor, it depends on the winding space of the stator, that is, the slot area. As shown in FIG. 46, the slot area is proportional to the product a × b of the circumferential length a and the radial length b since the shape of the slot is substantially rectangular.

  The length of the slot in the circumferential direction increases as the diameter of the cylinder increases, and is proportional to the diameter of the cylinder. The radial length dimension of the slot is directly proportional to the diameter of the cylinder. That is, the slot area is proportional to the square of the diameter of the cylinder. Also, as can be seen from the above equation (eq2), since the reluctance torque is proportional to the square of the stator current, the performance of the rotating electric machine is determined by how large a current can flow, and the performance depends on the slot area of the stator. Dependent. From the above, if the length of the cylinder is constant, the reluctance torque is proportional to the square of the diameter of the cylinder. Based on this, FIG. 45 is a diagram plotting the relationship between DM and magnet torque and reluctance torque.

  As shown in FIG. 45, the magnet torque increases linearly with DM, and the reluctance torque increases quadratically with DM. When the DM is relatively small, the magnet torque is dominant, and the reluctance torque is dominant as the stator core radius increases. The inventor of the present application has concluded that the intersection of the magnet torque and the reluctance torque in FIG. 45 is approximately in the vicinity of the stator core radius = 50 mm under the predetermined condition. In other words, in a 10 kW class motor in which the stator core radius is well over 50 mm, it is difficult to eliminate the core because the current mainstream is to utilize the reluctance torque. This is presumed to be one of the reasons that the slotless structure is not adopted.

  In the case of a rotating electric machine using an iron core for the stator, magnetic saturation of the iron core is always an issue. In particular, in the radial gap type rotating electric machine, the longitudinal section of the rotating shaft is fan-shaped per magnetic pole, and the magnetic path width becomes narrower toward the inner peripheral side of the device, and the inner peripheral side dimensions of the teeth forming the slots are the performance of the rotating electric machine. Set limits. No matter how high-performance a permanent magnet is used, if magnetic saturation occurs in this part, the performance of the permanent magnet cannot be fully exploited. In order to prevent magnetic saturation from occurring in this portion, the inner diameter must be designed to be large, resulting in an increase in the size of the device.

  For example, in the case of a distributed winding rotary electric machine, in the case of a three-phase winding, three to six teeth per magnetic pole share the magnetic flux, but the magnetic flux tends to concentrate on the teeth in the circumferential front. The magnetic flux does not flow evenly in three to six teeth. In this case, magnetic flux intensively flows through some (for example, one or two) teeth, and the teeth that are magnetically saturated with the rotation of the rotor also move in the circumferential direction. This is also a factor that causes slot ripple.

  From the above, in the rotating electric machine of the slotless structure in which the DM is 50 mm or more, it is desired to eliminate the teeth in order to eliminate the magnetic saturation. However, when the teeth are abolished, the magnetic resistance of the magnetic circuit in the rotor and the stator increases, and the torque of the rotating electric machine decreases. As a reason for the increase in magnetic resistance, for example, an air gap between the rotor and the stator may be large. For this reason, there is room for improvement in increasing the torque in the above-mentioned slotless rotating electric machine in which the DM is 50 mm or more. Therefore, there is a great merit in applying the above-described configuration capable of increasing the torque to the rotating electric machine having the slotless structure in which the DM is 50 mm or more.

  Not only for the rotating electric machine having the outer rotor structure but also for the rotating electric machine having the inner rotor structure, the radial distance DM between the surface of the magnet unit on the armature side in the radial direction and the axis of the rotor is 50 mm or more. May be.

  In the stator winding 51 of the rotary electric machine 10, the straight line portion 83 of the conducting wire 82 may be provided in a single layer in the radial direction. When the linear portion 83 is arranged in a plurality of layers inside and outside in the radial direction, the number of the layers may be arbitrary, and three, four, five, six, or the like may be provided.

  For example, in the configuration of FIG. 2, the rotating shaft 11 is provided so as to protrude at both the one end side and the other end side of the rotary electric machine 10 in the axial direction. Is also good. In this case, the rotating shaft 11 may be provided so as to extend outward in the axial direction with a portion supported by the bearing unit 20 in a cantilevered manner as an end. In this configuration, since the rotation shaft 11 does not protrude into the inverter unit 60, the internal space of the inverter unit 60, more specifically, the internal space of the tubular portion 71 can be used more widely.

  In the rotating electric machine 10 having the above-described configuration, the bearings 21 and 22 are configured to use the non-conductive grease. However, the configuration may be changed and the bearings 21 and 22 may be configured to use the conductive grease. For example, a configuration is used in which conductive grease containing metal particles, carbon particles, or the like is included.

  -As a structure which supports the rotating shaft 11 rotatably, it is good also as a structure which provides a bearing in two places of the axial direction one end side and the other end side of the rotor 40. In this case, in the configuration of FIG. 1, it is preferable that bearings are provided at two locations, one end side and the other end side, with the inverter unit 60 interposed therebetween.

  In the rotating electric machine 10 having the above configuration, the intermediate portion 45 of the magnet holder 41 in the rotor 40 has the inner shoulder portion 49a and the outer shoulder portion 49b of emotion. It may be configured to have various surfaces.

  In the rotating electric machine 10 having the above-described configuration, the conductor 82 a in the conductor 82 of the stator winding 51 is configured as an aggregate of a plurality of wires 86, but this is changed, and a rectangular conductor having a rectangular cross section is used as the conductor 82. It may be configured. Further, a configuration may be used in which a round conductor having a circular cross section or an elliptical cross section is used as the conductor 82.

  In the rotating electric machine 10 having the above-described configuration, the inverter unit 60 is provided inside the stator 50 in the radial direction. Alternatively, the inverter unit 60 may not be provided inside the stator 50 in the radial direction. . In this case, it is possible to leave an internal region radially inside the stator 50 as a space. Further, it is possible to arrange components different from the inverter unit 60 in the internal area.

  -It is good also as a structure which does not have the housing 30 in the rotary electric machine 10 of the said structure. In this case, for example, the rotor 40, the stator 50, and the like may be held in a part of a wheel or another vehicle part.

  In the above configuration, the periphery of the magnets 91, 92, 131, 132, 2001 may be covered with a resin coating. By doing so, it is possible to prevent an eddy current from flowing between adjacent magnets, and to reduce eddy current loss. Further, eddy current is prevented from flowing between the cylindrical portion 43 and the magnet, and eddy current loss can be reduced. That is, heat generation of the magnet unit 42 can be suppressed. In the case where a resin coating is provided, it is desirable that the peripheral surface and the circumferential end surface of the magnet opposite to the stator are covered with the resin coating so that the magnet unit 42 is exposed on the stator side. By exposing the stator-side outer surface of the magnet, a decrease in magnetic flux density due to the resin coating can be suppressed, and an air gap between the magnet unit 42 and the stator 50 can be reduced. The axial end surface of the magnet unit 42 may or may not be covered with the resin film.

  -In the said structure, you may mold the whole or part of the magnet unit 42 with resin. When molding the magnet unit 42 with a resin, the gap between the magnets in the circumferential direction may be filled with a resin wall having a predetermined width in the circumferential direction. Thereby, it becomes possible to stop or stop the rotation of the magnet in the circumferential direction by the resin wall disposed in the gap. Further, when the magnet unit 42 is molded with resin, the magnet unit 42 is formed such that a resin wall having a predetermined thickness dimension is arranged in the radial direction between the inner peripheral surface of the cylindrical portion 43 and the magnet unit 42. It may be molded. In this case, the resin wall between the cylindrical portion 43 and the magnet unit 42 functions as a cushioning member during rotation, so that the cylindrical portion 43 and the magnet unit 42 can be prevented from contacting each other.

  In the second embodiment, when molding the magnet unit 42 with resin, the groove 2004 may be filled with resin to restrict the movement of the magnet 2001 in the radial direction. By filling the groove 2004 with resin, even if the thickness of the resin layer between the magnet unit 42 and the stator 50 is reduced (or the resin layer is eliminated), the resin arranged in the groove 2004 It is possible to appropriately prevent falling off. This can prevent the magnet 2001 from moving in the radial direction and falling off during rotation.

  In the magnet unit 42 of the first embodiment, the magnets 91 and 92 are divided for each q axis, but the magnets 91 and 92 may be divided for the d axis. Further, the magnets 91 and 92 may be divided on the q axis and the d axis. In the magnet unit 42 of the second embodiment, the magnet 2001 may be divided on the q axis. That is, the magnet of the magnet unit 42 may be divided at an arbitrary position in the circumferential direction.

  In the second embodiment, the groove 2004 may not be provided.

  In the above-described configuration, the magnet unit 42 is directly fixed to the inner peripheral surface of the cylindrical portion 43. However, a magnet holding portion that holds the magnet unit 42 is provided separately from the magnet holder 41, and the magnet unit 42 is connected via the magnet holding portion. Thus, the magnet unit 42 may be fixed to the cylindrical portion 43 (that is, the magnet holder 41).

  For example, the rotating electric machine illustrated in FIGS. 47 to 49 includes the magnet holding unit 3001 that holds the magnet unit 42 having the plurality of magnets 2001 described in the second embodiment. The magnet holding portion 3001 is formed in a cylindrical shape, the outer peripheral surface is formed along the inner peripheral surface of the cylindrical portion 43, and the inner peripheral surface is formed along the outer peripheral surface of the magnet unit 42. Is formed. The magnet unit 42 is fixed and held on the inner peripheral surface of the magnet holder 3001, and the magnet holder 3001 is fixed on the inner peripheral surface of the cylindrical portion 43.

  As shown in FIGS. 48 and 49, similarly to the second embodiment, the magnet unit 42 has a concave portion 2002 that opens on the side opposite to the stator (that is, the magnet holding portion side). On the other hand, on the inner peripheral surface of the magnet holding portion 3001, a convex portion 3002 that engages with the concave portion 2002 of the magnet unit 42 in the circumferential direction is provided. More specifically, as shown in FIGS. 48 and 49, a convex portion 3002 is provided on the inner peripheral surface of the magnet holding portion 3001 so as to project toward the magnet unit (ie, the stator side) along the radial direction. These convex portions 3002 are formed so that the width in the circumferential direction becomes shorter as approaching the stator side in the radial direction so that the cross section becomes triangular according to the shape of the concave portion 2002. That is, a slope is provided from the magnet holding portion 3001 to the vertex of the convex portion 3002, and the slope is formed at an angle corresponding to the angle of the slope of the concave portion 2002 (ie, an angle of 45 degrees with respect to the radial direction). Have been. In addition, the dimension (height dimension) of the projection 3002 in the radial direction is the same as the dimension (depth dimension) of the recess 2002. This makes it possible to suitably engage the convex portion 3002 and the concave portion 2002.

  An engagement concave portion 3003 as an engaged portion that opens to the stator side is provided on the inner peripheral surface of the cylindrical portion 43, and an engagement concave portion as an engaging portion is provided on the outer peripheral surface of the magnet holding portion 3001. A mating projection 3004 is provided. The engagement concave portion 3003 is provided so as to engage with the engagement convex portion 3004 in the circumferential direction. Specifically, the engagement concave portion 3003 is formed so that the cross section becomes triangular. That is, it is formed so that the width in the circumferential direction becomes gradually smaller toward the outer side in the radial direction. The engagement projection 3004 is formed so as to have a triangular cross section according to the shape of the engagement recess 3003.

  Further, the position of the engaging protrusion 3004 (and the engaging recess 3003) in the circumferential direction is provided at a position different from the position of the protrusion 2003. Specifically, the engagement projection 3004 is provided on the q axis. Accordingly, it is possible to disperse the force applied from the cylindrical portion 43 to the magnet holding portion 3001 and the force applied from the magnet unit 42 to the magnet holding portion 3001 in the circumferential direction. Accordingly, the magnet holding unit 3001 can prevent a force from being applied from the inside and outside in the radial direction at the same position in the circumferential direction, and can suppress the deformation and the like of the magnet holding unit 3001.

  As described above, by providing the concave portion 2002, the convex portion 2003, the engaging concave portion 3003, and the engaging convex portion 3004, the rotation between the magnet holding portion 3001 and the magnet unit 42 is prevented, and the magnet holding portion 3001 and the cylinder are prevented. It is possible to suitably perform a rotation stop with the part 43, and it is possible to rotate them integrally. Further, by providing the cylindrical portion 43 and the magnet holding portion 3001 separately, the materials of the cylindrical portion 43 and the magnet holding portion 3001 can be made different. For example, the magnet holder 3001 can be made of a magnetic material and function as a back yoke. Note that, in the above alternative example, the engaging concave portion 3003 may be provided on the magnet holding portion 3001 and the engaging convex portion 3004 may be provided on the cylindrical portion 43.

  -In the said structure, the cylindrical part 43 and the intermediate | middle part 45 may be comprised separately. For example, as shown in FIG. 50, the cylindrical portion 43 may be fixed to the outer edge of the intermediate portion 45. In this case, as shown in FIGS. 50 and 51, a hole 4001 is provided in the cylindrical portion 43 and the (outer edge) of the intermediate portion 45 along the axial direction, and the hole 4001 is formed in a rod shape along the axial direction. What is necessary is just to insert the formed fastener, and to fix the cylindrical part 43 to the intermediate part 45 with a fastener. The fastener is, for example, a screw or a rivet. In another example shown in FIGS. 50 and 51, a rivet 4002 is illustrated as a fastener. In this case, the intermediate portion 45 functions as an end plate that fixes the cylindrical portion 43 as a magnet holding portion in the axial direction.

  Further, when the hole 4001 is provided in the cylindrical portion 43 in the second embodiment, it is desirable to provide the hole 4001 at a position overlapping the convex portion 2003 in the circumferential direction in consideration of the strength of the cylindrical portion 43. . For example, as shown in FIG. 51, it is desirable to provide the hole 4001 so that the center position of the hole 4001 and the center position (tip) of the protrusion 2003 coincide, that is, on the d-axis.

  Note that the cylindrical portion 43 and the intermediate portion 45 may be configured separately, and then the above-described magnet holding portion 3001 may be provided. In this case, as shown in FIG. 52, an engaging projection 3004 as an engaged portion is provided on the inner peripheral surface of the cylindrical portion 43, and an engaging concave portion 3003 as the engaging portion is provided on the outer peripheral surface of the magnet holding portion 3001. Is desirably provided. When the hole portion 4001 is provided in the cylindrical portion 43, the hole portion 4001 is positioned so that the center position of the hole portion 4001 and the center position (tip) of the engagement protrusion 3004 coincide with each other, that is, on the q axis. Is desirably provided.

  In the first embodiment, as shown in FIG. 53, a gap 1001 is provided between the magnets 91 and 92, and a side wall 1002 that protrudes radially from the inner peripheral surface of the cylindrical portion 43 is provided. The side wall 1002 may be circumferentially engaged with the end surface of the 92. In this case, it is desirable that the gap 1001 and the side wall 1002 are provided along the q-axis. Thus, the magnetic flux density distribution approximates a sine wave shape, and the rotation of the magnets 91 and 92 can be stopped.

  -In the said 2nd Embodiment, you may provide the magnet holding part 5001 comprised so that each magnet may be surrounded. That is, the rotor 40 may be of the IPM type. For example, as shown in FIG. 54, the magnet holding portion 5001 includes, in the radial direction, an inner wall portion 5002 arranged inside the magnet unit 42, an outer wall portion 5003 arranged outside the magnet unit 42, A side wall portion 5004 is provided along the radial direction so as to connect between the portion 5002 and the outer wall portion 5003 and to partition between the magnets 2001 adjacent in the circumferential direction. Each of the inner wall portion 5002 and the outer wall portion 5003 is formed in an annular shape along the circumferential direction. The side wall portion 5004 is provided along the d-axis, and is provided so as to partition the magnets 2001 one by one. That is, the side wall portion 5004 is provided at a position overlapping the convex portion 2003 in the circumferential direction. In this alternative example, the convex portion 2003 and the side wall portion 5004 are integrally formed, and the tip of the convex portion 2003 is formed. A side wall portion 5004 is provided so as to extend along the radial direction from. The width of the side wall 5004 is smaller than the width of the protrusion 2003 in the circumferential direction (more specifically, the width of the base end of the protrusion 2003).

  In this alternative example, the magnet holding portion 5001 is fixed to the inner peripheral surface of the cylindrical portion 43. In addition, it may be fixed to the outer edge of the intermediate portion 45 by screwing or the like. Further, the magnet holding portion 5001 may be provided by changing the configuration of the cylindrical portion 43. Further, in this alternative example, the magnets 2001 are partitioned one by one; however, a plurality (for example, two) of the magnets 2001 may be partitioned.

  According to the magnet holding portion 5001, the rotation can be stopped by the convex portion 2003. Therefore, even if the side wall portion 5004 is thinned and the strength is weakened, the rotation can be suitably stopped. In addition, by reducing the thickness of the side wall portion 5004, the gap between the magnets 2001 can be reduced to obtain a magnetic flux density distribution close to a sinusoidal shape, and the magnetic flux density on the d-axis can be improved. Further, since the inside and outside are surrounded by the inner wall portion 5002 and the outer wall portion 5003 of the magnet holding portion 5001 in the radial direction, it is possible to prevent the magnet holder 5001 from falling off in the radial direction.

  -In the said structure, you may change the shape of the convex part 2003 and the concave part 2002 arbitrarily. The cross section may be configured in a step shape. In addition, it may be configured to have a curved surface. Similarly, the shapes of the engagement protrusion 3004 and the engagement recess 3003 may be arbitrarily changed.

  The disclosure in this specification is not limited to the illustrated embodiment. The disclosure includes the illustrated embodiments and variations based thereon based on those skilled in the art. For example, the disclosure is not limited to the combination of parts and / or elements shown in the embodiments. The disclosure can be implemented in various combinations. The disclosure may have additional parts that can be added to the embodiments. The disclosure includes embodiments in which parts and / or elements are omitted. The disclosure encompasses the replacement or combination of parts and / or elements between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiments. Some of the disclosed technical ranges are indicated by the description of the claims, and should be construed to include all modifications within the scope and meaning equivalent to the description of the claims.

  DESCRIPTION OF SYMBOLS 10 ... Rotating electric machine, 40 ... Rotor (field element), 42 ... Magnet unit (magnet part), 50 ... Stator (armature), 51 ... Stator winding (armature winding), 57 ... Sealing Members (inter-conductor member), 81: conductor group (conductor portion), 82: conductor (conductor portion), 86: strand, 142: protrusion (inter-conductor member), 143: toothed portion (inter-conductor member), 2001: magnet, 2002: concave portion, 2003: convex portion.

Claims (7)

A magnet portion (42) including a plurality of magnetic poles having alternating polarities in a circumferential direction, and a cylindrical magnet holding portion (41, 3001, 5001) fixed in a state where the magnet portions are stacked in the radial direction. , And an armature (50) having a multi-phase armature winding (51), wherein one of the field element and the armature is used as a rotor. In the electric machine (10),
The magnet unit is oriented such that the direction of the easy axis of magnetization is parallel to the d-axis on the d-axis side, which is the center of the magnetic pole, compared to the q-axis side, which is the boundary of the magnetic pole, and the magnets are aligned along the easy axis of magnetization. A magnet (2001) having a magnetic path formed therein,
The magnet holding portion is disposed closer to the armature side than the magnet portion in the radial direction, and has a convex portion (2003, 3002) projecting toward the magnet portion in the radial direction.
A concave portion (2002) that opens in the anti-armature side and engages with the convex portion in the circumferential direction is provided in a portion of the magnet portion on the anti-armature side in the radial direction,
The rotating electric machine, wherein the concave portion is provided on a d-axis side rather than a q-axis side in a circumferential direction. The field element includes an end plate (45) for fixing the magnet holding unit in the axial direction,
A hole (4001) is provided in the magnet holding portion along the axial direction, and a fastener (4002) that projects from the end plate in the axial direction is inserted into the hole of the magnet holding portion. Has been
The rotating electric machine according to claim 1, wherein the hole is provided at a position overlapping the protrusion in a circumferential direction.   The rotating electric machine according to claim 2, wherein at least a part of the hole is provided at a position overlapping the protrusion in a radial direction.   4. The rotating electric machine according to claim 2, wherein a size of the protrusion in the radial direction is larger than a size of the hole. 5. The field element has a cylindrical portion (43) that is fixed in a state where the magnet holding portions are stacked on a side opposite to the armature in the radial direction of the magnet holding portion,
The magnet holding portion has an engaging portion (3004) that engages with the engaged portion (3003) provided on the cylindrical portion in a circumferential direction,
The rotating electric machine according to any one of claims 1 to 4, wherein the engagement portion is provided at a different position in a circumferential direction with respect to the protrusion. A plurality of the magnets are provided and are arranged side by side along the circumferential direction,
The magnet holding portion includes, in a radial direction, an inner wall portion (5002) arranged inside the magnet portion, an outer wall portion (5003) arranged outside the magnet portion, and the inner wall portion and the outer wall. A side wall portion (5004) provided along the radial direction so as to connect between the magnets and partition the circumferentially adjacent magnets,
The side wall portion is provided at a position overlapping the convex portion in the circumferential direction, and the width of the side wall portion in the circumferential direction is smaller than the width of the convex portion in the circumferential direction. The rotating electric machine according to any one of claims 1 to 5, wherein   The rotating electric machine according to any one of claims 1 to 6, wherein the magnet portion has a specific coercive force of 400 [kA / m] or more and a residual magnetic flux density of 1.0 [T] or more. .

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