WO2020084871A1 - Electrical machine - Google Patents

Abstract

An electrical machine (200) is provided with an armature (3) and a magnetic field (2), the magnetic field (2) being disposed so as to face the armature (3) across a gap (1) and to be movable in relation to the armature (3), and including a permanent magnet (50), formed so that magnetic poles (51), (52) with different poles on the armature (3) side are adjacent in the direction of movement, and a field core (15) in which the permanent magnet (50) is embedded. In an armature-side field core section (22) that is located closer to the armature (3) than the permanent magnet (50), a hole section (11) is formed by being recessed toward the permanent magnet (50) from a virtual surface (90) that is separated from the armature (3) in the direction toward the field core (15) by a distance equal to the minimum length of the gap (1), the hole section being formed at a location on an adjacency plane (24) that includes the plane where the magnetic poles (51), (52) are adjacent.

Description

Electric machine

The present invention relates to an electric machine having a field magnet in which a permanent magnet is embedded.

A conventional electric machine has a stator, which is an armature, a permanent magnet having a plurality of magnetic poles, and a field iron core, and faces the stator through a gap and moves relative to the stator. It has a mover that is a field. With this configuration, there is known a technique that achieves both a reduction in the number of permanent magnets and a reduction in manufacturing cost due to a reduction in the number of manufacturing steps of permanent magnets, and an improvement in torque (see, for example, Patent Document 1).

JP, 2006-288183, A

In Patent Document 1, a permanent magnet is embedded in a field iron core of a rotor that is a mover of a rotating electric machine. The permanent magnets are inserted into magnet insertion holes formed in the field core. This rotating electric machine is called an embedded permanent magnet rotating electric machine. Even when the permanent magnet is damaged, it is possible to prevent the fragments of the permanent magnet from staying in the magnet insertion hole of the field core and moving to the gap between the rotor and the stator.
Moreover, two magnetic poles having different poles on the stator side are adjacent to each other in the moving direction in one permanent magnet. A flux barrier is provided at a position along the adjacent surface of adjacent magnetic poles in the field core on the stator side of the permanent magnet, and the outer peripheral portion of the field core on the stator side of the permanent magnet is connected. ing. With this configuration, the magnetic flux that short-circuits the magnetic poles becomes difficult to pass, and the torque generated by the rotating electric machine increases.

However, the outer circumference of the field core located closer to the stator than the permanent magnet may not be magnetically saturated, depending on the magnitude of the current supplied to the stator. When the outer circumference of the field iron core is not magnetically saturated, the magnetic flux between adjacent magnetic poles is short-circuited through the outer circumference of the field iron core, which causes a problem that torque ripple, which is a pulsation of torque, increases.

The present invention has been made to solve the above-mentioned problems, and in the case where two magnetic poles having different poles on the armature side are adjacent to each other in the moving direction in the permanent magnet embedded in the field core. Another object of the present invention is to obtain an electric machine that reduces torque ripple more than when the outer circumference of a field iron core on the armature side of the permanent magnet is connected.

The electric machine according to the present invention is
With an armature,
A magnetic field facing the armature via a gap so as to be movable relative to the armature, and magnetic poles having different poles on the armature side are formed adjacent to each other in the moving direction. A magnet and a field having a field iron core in which a permanent magnet is embedded,
When the surface away from the armature at a distance equal to the minimum length of the air gap toward the field core is a virtual surface,
In the armature-side field iron core portion, which is the field iron core located closer to the armature than the permanent magnet, the hole that is recessed from the virtual surface toward the permanent magnet is the position of the adjacent surface including the surface where the magnetic poles are adjacent to each other. It is formed in.

In the electric machine configured as described above, in the permanent magnet embedded in the field iron core, when two magnetic poles having different poles on the armature side are adjacent to each other in the moving direction, the armature side is closer to the permanent magnet than the permanent magnet. The torque ripple can be reduced as compared with the case where the outer circumference of the field iron core in FIG.

It is a diagram of a drive system in the first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 of the electric machine in the first embodiment of the present invention. FIG. 3 is a partial cross-sectional view of the electric machine according to the first embodiment of the present invention. It is a figure which shows the waveform of the magnetic flux density of the air gap of the electric machine in Embodiment 1 of this invention. FIG. 6 is a partial cross-sectional view of a first comparative example of the electric machine according to the first embodiment of the present invention. It is a figure which shows the waveform of the magnetic flux density of the air gap in the 1st comparative example of the electric machine in Embodiment 1 of this invention. FIG. 6 is a diagram showing a 6f component of torque ripple in the electric machine according to the first embodiment of the present invention and the electric machine according to the first comparative example. FIG. 7 is a partial cross-sectional view of a first modified example of the electric machine according to the first embodiment of the present invention. FIG. 13 is a cross-sectional view taken along the line AA of FIG. 1 in a rotor of a second modified example of the electric machine according to Embodiment 2 of the present invention. It is a fragmentary sectional view of the 2nd modification of the electric machine in Embodiment 2 of this invention. It is a partial cross section figure of the 3rd modification of the electric machine in Embodiment 3 of this invention. It is a fragmentary sectional view of the 4th modification of the electric machine in Embodiment 3 of this invention. It is a fragmentary sectional view of the 5th modification of the electric machine in Embodiment 3 of this invention. It is a fragmentary sectional view of the 6th modification of the electric machine in Embodiment 3 of this invention. It is a fragmentary sectional view of the 7th modification of the electric machine in Embodiment 4 of this invention. It is a fragmentary sectional view of the 8th modification of the electric machine in Embodiment 5 of this invention. It is a perspective view of the rotor of the 9th modification of the electric machine in Embodiment 6 of this invention. FIG. 20 is a sectional view taken along line GG of FIG. 17 showing a ninth modification of the electric machine according to the sixth embodiment of the present invention. It is a perspective view of the rotor of the 10th modification of the electric machine in Embodiment 6 of this invention. It is a partial cross section figure of the 11th modification of the electric machine in Embodiment 7 of this invention. It is a partial cross section figure of the 12th modification of the electric machine in Embodiment 7 of this invention.

Preferred embodiments for carrying out the present invention will be described below with reference to the drawings.
Embodiment 1.
FIG. 1 is a diagram of a drive system according to a first embodiment for carrying out the present invention. In FIG. 1, a drive system 500 includes a rotating electric machine 200 that is an electric machine and an inverter 100. The rotary electric machine 200 and the inverter 100 are electrically connected to each other, and a three-phase alternating current is supplied from the inverter 100 to the rotary electric machine 200. The diagram of the rotary electric machine 200 in FIG. 1 is shown in a side sectional view which is a cross-sectional view in a plane including the rotation axis of the rotary electric machine 200. Hereinafter, the rotation axis will be referred to as the axis.

In FIG. 1, a rotating electric machine 200 according to the present embodiment includes a stator 3 that is an armature and a rotor 2 that is a field. The rotor 2 is fixed to the outer peripheral surface of the support shaft 4. Two bearings 5 are fitted to the outer peripheral surfaces of both ends of the support shaft 4 in the axial direction and both ends of the rotor 2 in the axial direction. Outer peripheral surfaces of the two bearings 5 are fitted to the inner peripheral surface of the housing 9 and are held by the housing 9. The outer peripheral surface of the stator 3 is fitted and fixed to the inner peripheral surface of the housing 9. With these configurations, the rotor 2 rotates about the axis of the support shaft 4. That is, the rotor 2 is arranged so as to face the stator 3 through the gap 1 and to be movable relative to the stator 3, that is, to be rotatable.

FIG. 2 is a sectional view of the electric machine taken along the line AA in FIG. 1 according to the present embodiment. The cross-sectional view is a cross-sectional view in a plane orthogonal to the rotation axis of the rotating electric machine 200 that is an electric machine. In FIG. 2, the stator 3 includes a stator core 16 which is an armature core, twelve windings 6, and twelve insulators 8. The stator core 16 has an annular core back portion 17 and twelve teeth portions 18 protruding from the core back portion 17 to the rotor 2 side and arranged at equal intervals in a rotation direction which is a moving direction, that is, a circumferential direction. . The stator core 16 is formed by stacking a plurality of sheet-shaped stator core sheets 16-1 punched in the same shape from an electromagnetic steel sheet in a predetermined length in the axial direction for the purpose of reducing eddy currents. There is. The teeth portion 18 of the stator core 16 is arranged so as to face the rotor 2 with the gap 1 interposed therebetween. Twelve slots 21 are formed between the teeth portions 18 that are adjacent to each other in the circumferential direction. The twelve windings 6 are wound around the teeth portion 18 via the insulator 8 and are respectively housed in the twelve slots 21. The winding 6 is composed of four windings 6 per phase and a total of 12 windings 6 for three phases. Four windings 6 per phase are connected in series to form a phase winding group, and the phase winding groups for three phases are Y-connected. When a three-phase alternating current is applied to each phase winding group having the winding 6 from the inverter 100, which is a power converter, with a phase difference of 120 ° between the phases, a rotating magnetic field rotating in the circumferential direction is generated. 3 is generated in the air gap 1 and torque is generated in the rotor 2. The method of connecting the three-phase phase winding group is not limited to Y connection and may be Δ connection.

The rotor 2 has four permanent magnets 50 and a rotor core 15 which is a field core in which the four permanent magnets 50 are embedded. The rotor core 15 is configured by laminating a plurality of sheet-shaped rotor core sheets 15-1 punched in the same shape from electromagnetic steel sheets in a predetermined length in the axial direction. The rotor core 15 is provided with four magnet insertion holes 19 into which the permanent magnets 50 are inserted, the same number as the permanent magnets 50, at equal intervals in the circumferential direction. One permanent magnet 50 is inserted into each of the four magnet insertion holes 19.

At both ends of the magnet insertion hole 19 in the circumferential direction, flux barriers 7 which are holes penetrating in the axial direction and suppressing a short circuit of magnetic flux between the permanent magnets 50 inserted in the magnet insertion holes 19 adjacent to each other in the circumferential direction are provided. It is provided. A non-magnetic material such as resin may be inserted in the flux barrier 7.

On the permanent magnet 50, magnetic poles 51 and 52 having different poles on the side of the stator 3 which is an armature are formed adjacent to each other in the rotational direction which is the moving direction, that is, the circumferential direction. That is, in FIG. 1, the magnetic pole 51 is magnetized so that it has an N-pole on the surface on the side of the stator 3 and the magnetic pole 52 has an S-pole on the surface on the side of the stator 3. The N pole of the magnetic pole 51 is formed on the surface on the side of the stator 3 on one side in the circumferential direction from the center of the permanent magnet 50, that is, the surface on the outer side in the radial direction. The S pole of the magnetic pole 52 is formed on the surface on the side of the stator 3 on the other side in the circumferential direction from the center of the permanent magnet 50, that is, the surface on the outer side in the radial direction. The surface where the magnetic poles 51 and 52 are adjacent to each other in the circumferential direction is the magnetic pole boundary 10.
In FIG. 2, since the total number of the magnetic poles 51 and 52 appearing in the air gap 1 is eight, the rotary electric machine 200 is a rotary electric machine having eight magnetic poles 51 and 52 and twelve slots 21. There is.

The permanent magnet 50 has a flat plate shape. That is, the permanent magnet 50 has two flat surfaces facing each other, and the surface of the permanent magnet 50 on the side of the stator 3 where the magnetic poles 51 and 52 are formed is one flat surface. In FIG. 2, the cross-sectional shape of the permanent magnet 50 in the cross section including the radial direction, which is the direction from the permanent magnet 50 toward the stator 3, and the circumferential direction is a rectangle. The cross section including the radial direction and the circumferential direction is a cross section orthogonal to the axial direction. The permanent magnets 50 extend in the axial direction with a sectional shape orthogonal to the same axial direction. In FIG. 2, the axial length of the permanent magnet 50 is equal to the axial length of the rotor core 15. The axial length of the permanent magnet 50 may be different from the axial length of the rotor core 15.
Since the permanent magnet 50 has a flat plate shape, it is possible to reduce the number of man-hours required to shape the permanent magnet 50, as compared with the case where the permanent magnet has a curved surface shape.

The magnetic poles 51 and 52 may be configured as separate segment magnets, that is, magnetic bodies that are separate permanent magnet pieces. That is, the permanent magnet 50 may be composed of a plurality of magnetic bodies divided into magnetic poles 51 and 52. In the case of FIG. 2, the permanent magnet 50 may be composed of two magnetic bodies divided into magnetic poles 51 and 52. With this configuration, it is possible to magnetize each magnetic body of the permanent magnet pieces and form a magnetic pole for each magnetic body. Therefore, it is possible to improve the magnetization ratio, which is the ratio of the magnetic flux generated by the magnetized permanent magnet piece to the magnetic flux generated by the permanent magnet piece in the completely magnetized state.

Further, by magnetizing a magnetic body that is one permanent magnet piece that is an integral segment magnet, magnetic poles 51 and 52 having different poles on the side of the stator 3 of the permanent magnet 50 are circumferentially arranged. It may be formed adjacently. That is, the permanent magnet 50 may be composed of one magnetic body having a plurality of magnetic poles 51 and 52. With this configuration, it is possible to reduce costs related to the number of control points of the permanent magnet 50, the number of processing steps, and the number of magnetizing steps.

In FIG. 2, when the permanent magnet 50 is composed of two magnetic bodies in which the magnetic poles 51 and 52 are formed, the magnetic pole boundary 10 has two magnetic bodies adjacent to each other in the circumferential direction. It becomes a face. When the permanent magnet 50 is composed of one magnetic body, the magnetic pole boundary 10 is located at a circumferential position where the pole is switched from the N pole to the S pole or from the S pole to the N pole, that is, the circumference without the pole. It becomes the surface of the direction position. Further, in the case where the permanent magnet 50 is composed of one magnetic body, a region having no pole exists in the circumferential direction at the circumferential ends of the magnetic poles 51, 52 on the side where the magnetic poles 51, 52 are circumferentially adjacent to each other. In this case, the magnetic pole boundary 10 is a surface located at the center position of the circumferential range of the region having no pole.

Alternatively, the permanent magnet 50 may be magnetized with an arbitrary number of magnetic poles 51 and 52 having two or more poles. That is, the number of magnetic poles 51 and 52 in the permanent magnet 50 may be three or more.

FIG. 3 is a partial cross-sectional view of the electric machine according to this embodiment. In FIG. 3, the rotor core 15 positioned closer to the stator 3 than the permanent magnet 50 is referred to as an armature side field core portion 22. A surface that is separated from the stator 3 in the direction toward the rotor core 15 with a distance equal to the minimum length g of the gap 1 is defined as a virtual surface 90. A surface including the magnetic pole boundary 10 which is a surface where the magnetic poles 51 and 52 are adjacent to each other is referred to as an adjacent surface 24. In the armature side field iron core portion 22, a hole portion 11 recessed from the virtual surface 90 toward the permanent magnet 50 is formed at the position of the adjacent surface 24. Here, the minimum length g of the gap 1 represents the minimum radial distance between the teeth portion 18 of the stator core 16 and the rotor core 15. The boundary of the armature side field core portion 22 is a portion of the rotor core 15 that is the minimum width tb in the direction from the circumferential end of the permanent magnet 50 toward the stator 3. In FIG. 3, the virtual surface 90 is a cylindrical surface that is separated from the stator 3 in the direction toward the rotor core 15 with the minimum length g of the gap 1.

The hole 11 is formed in the armature side field iron core portion 22 so as to straddle the adjacent surface 24 in the circumferential direction. The cross-sectional shape of the hole 11 in the cross section perpendicular to the axial direction is a wedge shape in which the width in the moving direction becomes narrower in the direction from the virtual surface 90 toward the permanent magnet 50 side and becomes convex.

In FIG. 3, in the circumferential range occupied by the hole 11, the permanent magnet 50 in the armature side field iron core portion 22 facing the one magnetic pole 51 in the radial direction from the permanent magnet 50 to the stator 3. From the permanent magnet 50 in the armature side field core portion 22 facing the other magnetic pole 52 adjacent to the one magnetic pole 51, and the maximum radial distance from the permanent magnet 50. The opening width, which is the length of the straight line connecting to and, is Wh1, and is the width in the moving direction that is the direction perpendicular to the magnetizing direction corresponding to one pole of the magnetic pole 51 or the magnetic pole 52 of the permanent magnet 50, that is, the width in the circumferential direction. The magnetic pole width is Wmag. At this time, the opening width Wh1 is preferably set to be smaller than the magnetic pole width Wmag and larger than the minimum length g of the gap 1. That is, it is desirable that g <Wh1 <Wmag.

This is because, in FIG. 3, when the size of the hole 11 is not enough to suppress the magnetic flux 20 from flowing through the path B of the magnetic flux 20 that short-circuits the magnetic pole 51 and the magnetic pole 52, that is, the magnetic pole boundary. When the magnetic resistance of the path B of the magnetic flux 20 extending over the extension of 10 is low, the magnetic flux 20 from the magnetic pole 51 passes through the path B of the magnetic flux 20 and is short-circuited to the adjacent magnetic pole 52, which may reduce the torque. Because there is. When g <Wh1, the magnetic flux 20 flowing through the magnetic poles 51 and 52 passes through the gap 1 more easily than the opening width Wh1. When Wh1 <Wmag, the range in which the opening width Wh1 overlaps the magnetic poles 51 and 52 in the circumferential direction becomes smaller than the magnetic pole width Wmag, and the magnetic flux 20 of the magnetic poles 51 and 52 passes in the circumferential range of the hole 11. It is possible to suppress the length of the void 1 from expanding beyond the minimum length g. Due to this dimensional relationship, the magnetic flux density in the gap 1 between the rotor 2 and the stator 3 can be efficiently increased, and the torque can be further increased.

Further, in FIG. 3, the radial width of the armature-side field core portion 22 in the direction of the adjacent surface 24 from the permanent magnet 50 to the stator 3 is th1, and the armature-side field core portion 22 has a width of th1. The minimum width in the direction from the circumferential end of the permanent magnet 50 toward the stator 3 is tb. In addition, the portion of the rotor core 15 in the same range as the circumferential range of the hole 11 including the portion having the width th1 in the armature side field core portion 22 is the first bridge portion, that is, the thin portion 13, and th1 is It is the width of the thin portion 13. Further, the stator 3 side than the flux barrier 7 from the portion having the minimum width tb at the boundary of the armature side field iron core portion 22 to the minimum width tb at the boundary of the armature side field iron core portions 22 adjacent in the circumferential direction. The portion of the rotor core 15 located at is the second bridge portion 26. The 2nd bridge part 26 straddles the position of the central surface 25 which is a surface located in the center of the circumferential direction between the permanent magnets 50 adjacent to each other in the circumferential direction.

In order to cause magnetic saturation in the thin portion 13, it is desirable to set the width th1 of the thin portion 13 as small as possible. That is, the width th1 of the thin portion 13 is preferably tb ≦ th1 <Wh1 / 2 with respect to the minimum width tb and the opening width Wh1. This is because the lower limit value of the width th1 of the thin portion 13 is set to the minimum width tb that has the strength to hold the centrifugal force generated in the permanent magnet 50 due to the rotation of the rotor, or the minimum width tb of the size that allows the electromagnetic steel plate to be punched. This is because it is necessary. When th1 <Wh1 / 2, the amount of magnetic flux that passes through the width th1 of the thin portion 13 among the magnetic flux 20 that flows through the magnetic poles 51 and 52 is greater than the amount of magnetic flux that flows from the opening width Wh1 into the air gap 1. Is also smaller. Due to this dimensional relationship, magnetic saturation easily occurs in the thin portion 13 due to the magnetic flux 20 generated by the permanent magnet 50 or the magnetic flux generated by the stator 3. When the thin portion 13 is magnetically saturated, the relative permeability of the thin portion 13 is close to that of air. Therefore, the torque generated by the rotary electric machine 200 can be further increased.

Note that g <Wh1 <Wmag and tb ≦ th1 <Wh1 / 2 are dimensions that can be set individually, and the effect of increasing torque is also achieved. Further, if g <Wh1 <Wmag and tb ≦ th1 <Wh1 / 2, the torque is increased as compared with the case of setting by any dimensional relationship.

In general, when the electromagnetic steel sheet used for the rotor core 15 is manufactured by punching, the magnetic resistance is reduced due to the deterioration of processing due to the punching in the range of the thickness of the electromagnetic steel sheet from the contour of the punched shape. Increase, and magnetic saturation easily occurs in this range. Therefore, it is desirable that the width th1 of the thin portion 13 is equal to or less than that of two electromagnetic steel plates, preferably equal to or less than that of one electromagnetic steel plate.

Next, the effect of torque ripple in rotary electric machine 200 of the present embodiment will be described.
FIG. 4 is a diagram showing a waveform of the magnetic flux density in the air gap of the electric machine according to the present embodiment. 4, the horizontal axis represents the position of the rotor of the rotary electric machine 200 in the circumferential direction, that is, the rotation angle of the rotor is represented by an electrical angle [deg], and the vertical axis represents the magnetic flux density in the void 1 in the void 1 in FIG. It is expressed as a value standardized by the maximum value of the magnetic flux density in. In FIG. 4, the waveform of the magnetic flux density in the air gap 1 of the rotary electric machine 200 that is the electric machine according to the present embodiment has a sinusoidal shape. Further, in FIG. 4, the position where the magnetic flux density is 0 is the circumferential position between the magnetic poles having different poles, that is, the position of the electrical angle 180 [deg] which is the circumferential position of the adjacent surface 24, and the field iron core 15. It is the position in the circumferential direction between the flux barriers 7 that are adjacent to each other, that is, the position of the electrical angle 0 [deg] or 360 [deg] that is the position of the center plane 25.

FIG. 5 is a partial cross-sectional view of a first comparative example of the electric machine according to the present embodiment.
In FIG. 5, a rotating electric machine 300, which is a first comparative example of the electric machine according to the present embodiment, has a stator 303 that is the same as the stator 3 shown in FIG. 2 and an embedded permanent magnet 350 embedded in a rotor core 315. And a rotor 302 of the embedded magnet type. The rotor 302 of the rotary electric machine 300 of FIG. 5 differs from the rotary electric machine 200 of FIG. 3 in that a recess 312 is formed instead of the hole 11. Other configurations of the rotary electric machine 300 are similar to those of the rotary electric machine 200 of FIG.

In FIG. 5, similarly to the rotating electric machine 200 of the present embodiment of FIG. 3, one permanent magnet 350 in the rotating electric machine 300 has magnetic poles 351 and 352 having different poles on the stator 303 side in the moving direction. It is formed by being magnetized adjacent to a certain circumferential direction. In the armature side field iron core portion 322, which is the rotor iron core 315 located closer to the stator 300 than the permanent magnet 350 in the rotor 302, the concave portion 312 that is recessed from the magnet insertion hole 319 toward the stator 300 side, The magnetic poles 351 and 352 are formed at the position of the adjacent surface 324 including the magnetic pole boundary 310 which is a surface where the magnetic poles 351 and 352 are adjacent to each other. That is, in the rotary electric machine 300, the outer peripheral portion of the rotor core 315 located closer to the stator 300 than the permanent magnet 350 is connected by the thin portion 313.

FIG. 6 is a diagram showing a waveform of the magnetic flux density of the air gap in the first comparative example of the electric machine according to the present embodiment. 6, the horizontal axis represents the position of the rotor of the rotary electric machine 300 in the circumferential direction, that is, the rotation angle of the rotor in electrical degrees [deg], and the vertical axis represents the air gap 301 of the rotary electric machine 300 of the first comparative example. The magnetic flux density at is represented by a value normalized by the maximum value of the magnetic flux density in the void 301 in FIG. 6, the waveform of the magnetic flux density in the air gap 301 of the rotary electric machine 300 of the first comparative example of the electric machine according to the present embodiment is larger in the air gap 1 than in the air gap 1 of the rotary electric machine 200 in FIG. It has a trapezoidal waveform that contains many harmonic components in the circumferential space. Here, the harmonic component in the space in the circumferential direction is a harmonic component when the waveform of two poles of the magnetic pole 51 and the magnetic pole 52, that is, one electrical angle period is subjected to frequency analysis.

In the rotating electric machine 300 of FIG. 5, the outer peripheral portion of the armature side field iron core portion 322, which is the rotor iron core 315 on the stator 300 side of the permanent magnet 350, is connected by the thin portion 313. Therefore, in the rotary electric machine 300 of FIG. 5, the magnetic flux 320 of the permanent magnet 350 flows through the thin portion 313 connected at the outer peripheral portion of the armature side field iron core portion 322.

On the other hand, in the rotary electric machine 200 of the present embodiment of FIG. 3, the hole portion 11 recessed from the virtual surface 90 toward the permanent magnet 50 is formed at the position of the adjacent surface 24. Therefore, the magnetic flux 20 of the permanent magnet 50 is connected to the armature side field iron core portion 22 at a portion closer to the permanent magnet 50 side than the outer peripheral portion of the armature side field iron core portion 22. Flowing through.
Therefore, the magnetic flux density of the air gap 1 in the adjacent surface 24 located between the magnetic poles 51 and 52 of the rotating electric machine 200 is the air gap 301 at the magnetic pole boundary 310 located between the magnetic poles 351 and 352 of the rotating electric machine 300 of the first comparative example. Lower than the magnetic flux density of. Therefore, as shown in FIG. 6, the harmonic component of the magnetic flux density in the air gap 1 of the rotary electric machine 200 is smaller than the harmonic component of the magnetic flux density in the air gap 301 of the rotary electric machine 300.

As a result, the torque ripple of the rotary electric machine 200 of the present embodiment in FIG. 3 is reduced as compared with the torque ripple of the rotary electric machine 300 of the first comparative example. That is, when two magnetic poles 51 and 52 having different poles on the side of the stator 3 in one permanent magnet 50 embedded in the rotor core 15 are adjacent to each other in the moving direction, the rotating electric machine of the present embodiment In the case of 200, the torque ripple can be reduced as compared with the case where the outer peripheral portion of the armature side field iron core portion 322 on the stator 300 side of the permanent magnet 350 is connected.

FIG. 7 is a diagram showing a 6f component of torque ripple in the electric machine according to the present embodiment and the electric machine according to the first comparative example. 7, the horizontal axis represents the rotating electrical machine 300 of the first comparative example of FIG. 5 and the rotating electrical machine 200 of FIG. 3, and the vertical axis represents the 6f component of the torque ripple of the first comparative example as 100. It represents the 6f component of the torque ripple. Here, the 6f component of the torque ripple is the amplitude value of the torque ripple of 6 peaks per one electrical angle cycle when a predetermined current is applied to the stator, and is the main component of the torque ripple. As a result of the electromagnetic field analysis, the 6f component of the torque ripple of the rotary electric machine 200 in FIG. 3 is 12% lower than the 6f component of the torque ripple of the rotary electric machine 300 of the first comparative example. This is because the hole portion 11 of the rotary electric machine 200 in FIG. 3 can reduce the harmonic component of the magnetic flux density in the air gap 1 of the rotary electric machine 200 to a higher level than the harmonic component of the magnetic flux density in the air gap 301 of the rotary electric machine 300. . Therefore, the torque ripple of rotary electric machine 200 of the present embodiment in FIG. 3 can be reduced as compared to the torque ripple of rotary electric machine 300 of the first comparative example.

The cross-sectional shape of the hole portion 11 is not limited to the shape symmetrical in the circumferential direction with respect to the adjacent surface 24, and if the shape is recessed from the virtual surface 90 toward the permanent magnet 50, the hole 11 has a circumferential shape with respect to the adjacent surface 24. The shape may be asymmetric in the direction. Even if the cross-sectional shape of the hole 11 is asymmetrical in the circumferential direction with respect to the adjacent surface 24, the harmonic component of the magnetic flux density in the air gap 1 of the rotary electric machine 200 is the harmonic component of the magnetic flux density in the air gap 301 of the rotary electric machine 300. The torque ripple of the rotary electric machine 200 can be reduced more than that of the rotary electric machine 300 of the first comparative example.

Next, the effect of the torque of rotary electric machine 200 of the present embodiment will be described.
The rotary electric machine 200 of the present embodiment is different from the rotary electric machine of the second comparative example in which the hole 11 of the rotary electric machine 200 of the present embodiment is not provided in the rotor iron core, in the armature side field core. The magnetic resistance of the armature side field core portion 22 is increased by the hole portion 11 provided in the portion 22.

Specifically, in FIG. 3, in the hole portion 11, at the position of the adjacent surface 24 of the armature side field iron core portion 22, the magnetic flux 20 passes through the path B of the magnetic flux 20 that short-circuits between the magnetic pole 51 and the magnetic pole 52. It is provided to prevent flow. Due to this hole portion 11, the cross-sectional area of the thin portion 13 of the armature side field iron core portion 22 due to the cross section of the adjacent surface 24 becomes smaller than that of the rotating electric machine of the second comparative example. Therefore, the magnetic resistance in the path B of the magnetic flux 20 that short-circuits the magnetic pole 51 and the magnetic pole 52 in the rotary electric machine 200 according to the present embodiment is the same as that in the second comparative example in which the hole 11 is not provided in the rotor core. It is larger than that of the rotating electric machine.

Therefore, the magnetic flux 20 that short-circuits the adjacent magnetic poles 51 and 52 is suppressed more than in the case of the rotating electrical machine of the second comparative example. As a result, the torque generated by the rotary electric machine 200 of FIG. 3 can be made larger than the torque generated by the rotary electric machine of the second comparative example.

Next, the effect of manufacturability on the permanent magnet 50 in the rotary electric machine 200 of the present embodiment will be described.
If the total number of magnetic poles of the rotating electric machine of the third comparative example is eight, which is the same as the total number of magnetic poles 51 and 52 of FIG. 2 in the present embodiment, in the rotating electric machine of the third comparative example, the magnet insertion formed in the rotor is inserted. The number of holes and the number of permanent magnets are eight, which is the same as the total number of magnetic poles. In this case, the number of magnet insertion holes or permanent magnets of the rotating electrical machine of the third comparative example is eight, which is twice the number of four in the present embodiment. In the rotating electrical machine of the third comparative example, one magnetic pole having an N-pole or an S-pole is formed on the stator-side surface of one permanent magnet embedded in the rotor. Has been done.
Therefore, in the rotating electrical machine of the third comparative example, the man-hours for shaping the permanent magnets, the man-hours for magnetizing the permanent magnets, and the man-hours for inserting the permanent magnets into the magnet insertion holes depend on the total number of magnetic poles. There is a problem in that the manufacturing cost is increased.

On the other hand, in the rotary electric machine 200 of the present embodiment, two magnetic poles 51 and 52 are magnetized and formed in one flat permanent magnet 50. Further, the number of magnet insertion holes 19 or permanent magnets 50 is four, which is half that of the rotating electrical machine of the third comparative example. Therefore, the number of man-hours for shaping the permanent magnet 50 of the rotary electric machine 200 of the present embodiment is half that of the rotary electric machine of the third comparative example.
Further, when the permanent magnets 50 are magnetized before inserting the permanent magnets 50 into the magnet insertion holes 19, since one permanent magnet 50 is magnetized once, the rotation of the present embodiment is performed. The number of magnetizing steps in the electric machine 200 is half that of the rotating electric machine of the third comparative example.
Further, the number of steps for inserting the permanent magnet 50 of the rotary electric machine 200 of the present embodiment into the magnet insertion hole 19 is also half that of the rotary electric machine of the third comparative example.

Therefore, in the rotary electric machine 200, it is possible to reduce man-hours for shaping the permanent magnet 50, man-hours for magnetizing the permanent magnet 50 for generating the magnetic poles 51 and 52, and man-hours for inserting the permanent magnet 50 into the magnet insertion hole 19. . Therefore, the manufacturing cost of the rotary electric machine 200 of the present embodiment can be reduced as compared with the rotary electric machine of the third comparative example.

Next, a first modification 200a of the rotary electric machine according to the present embodiment will be described.
FIG. 8 is a partial cross-sectional view of a first modification 200a of the electric machine according to the present embodiment. 8, in addition to the hole portion 11 formed at the position of the adjacent surface 24 in the rotary electric machine 200 shown in FIG. 3, the cutout portion 23 is provided between the adjacent permanent magnets 50 on the outer peripheral portion of the rotor core 15a. Is provided. That is, the notch 23 recessed from the virtual surface 90 in the direction from the stator 3 to the rotor core 15a is located at the center of the rotor core 15a in the circumferential direction between the permanent magnets 50 adjacent to each other in the circumferential direction. It is formed at the position of the central surface 25 which is the surface to be formed.

When the permanent magnets 50-1 and 50-2 adjacent to each other in the circumferential direction with the cutout portion 23 interposed therebetween are the first permanent magnet 50-1 and the second permanent magnet 50-2, the first permanent magnet The armature side field core at the position of the adjacent surface 24-1 which is the surface including the magnetic pole boundary 10-1 which is one end surface in the circumferential direction of the first magnetic pole 51-1 closest to the cutout portion 23 in 50-1. A first hole 11-1 is formed in the portion 22. In the rotor iron core 15a, the first magnetic pole 51-1 having the first magnetic pole 51-1 formed between the first hole portion 11-1 and the cutout portion 23 protrudes from the permanent magnet 50-1 toward the stator 3. One protruding portion 30a-1 is formed. In the second permanent magnet 50-2, the armature side field at the position of the adjacent surface 24-2 including the magnetic pole boundary 10-2 which is one circumferential end surface of the second magnetic pole 52-2 closest to the cutout portion 23. A second hole portion 11-2 is formed in the magnetic core portion 22-2. Then, in the rotor core 15a, between the second hole portion 11-2 and the notch portion 23, the second protruding portion 30a− protruding from the second permanent magnet 50-2 toward the stator 3 is formed. 2 is formed.

By combining the cutout portion 23 and the flux barrier 7 between the first protruding portion 30a-1 and the second protruding portion 30a-2, the short circuit of the magnetic flux 20 between the adjacent permanent magnets 50 is suppressed. can do. Therefore, the torque of the rotary electric machine 200a in FIG. 8 is larger than the torque of the rotary electric machine 200 in FIG. Even if the flux barrier 7 is not provided, the cutout 23 alone can suppress the short circuit of the magnetic flux 20 between the adjacent permanent magnets 50, compared to the case where the cutout 23 is not provided.

Further, the gap 1 between the magnetic pole 51-1 and the magnetic pole 52-2, which is between the adjacent permanent magnets 50-1 and 50-2, is formed by the first protrusion 30a-1 and the second protrusion 30a-2. The magnetic flux density can be reduced. Therefore, it is possible to ensure the symmetry of the magnetic flux density of the air gap 1 with reference to the center plane 25 between the magnetic poles 51-1 and 52-2 of the rotor core 15a. That is, the waveform of the magnetic flux density of the air gap 1 approaches antisymmetry with respect to the center plane 25 between the magnetic pole 51-1 and the magnetic pole 52-2. Therefore, the first modification 200a of the rotary electric machine can reduce the torque ripple more than the rotary electric machine 200 of FIG.

In the present embodiment, the number of magnetic poles 51, 52 appearing in the gap 1 by the permanent magnet 50 is eight, that is, eight magnetic poles and the number of slots 21 is twelve, but the rotating electric machines 200, 200a are used. The number of slots and the number of slots 21 may be any combination that satisfies the desired characteristics of the rotary electric machine.

In the present embodiment, the rotors 2 and 2a are housed in the inner diameter side of the stator 3 and face the inner diameter side of the stator 3, but the inner rotor type rotary electric machines 200 and 200a have the structure. The same effect can be obtained as the structure of the outer rotor type rotating electric machine in which the rotors 2 and 2a are arranged to face the outer diameter side of the rotor 3.

In the case of the inner rotor type, it is possible to make the cross-sectional area perpendicular to the axial direction of the slots 21 in the stator core 16 larger than the cross-sectional area of the outer rotor type slots. Therefore, the copper loss of the stator 3 can be reduced.
Further, in the case of the outer rotor type, centrifugal force does not act on the thin portion of the rotor core, so the thickness of the thin portion of the rotor core should be smaller than the thickness of the thin portion 13 of the inner rotor type rotor core 15. You can

Embodiment 2.
FIG. 9 is a sectional view taken along line AA of FIG. 1 showing a rotor of a second modified example of the electric machine according to the second exemplary embodiment of the present invention. FIG. 10 is a partial cross-sectional view of a second modified example of the electric machine according to the present embodiment. 9 and 10, the second modification 200b of the rotary electric machine that is an electric machine is different from the first modification 200a of the rotary electric machine according to the first embodiment in the following points.

In FIG. 9, the first protrusion 30b-1 has a circular arc-shaped cross section perpendicular to the axial direction, and the second protrusion 30b-2 has a circular cross-sectional shape perpendicular to the axial direction. It has an arc shape. The radius of curvature of the first protrusion 30b-1 is r1, the radius of curvature of the second protrusion 30b-2 is r2, and the radius of curvature of the cross section of the virtual surface 90 shown in FIG. To do. At this time, the radius of curvature r1 of the first protrusion 30b-1 and the radius of curvature r2 of the second protrusion 30b-2 are smaller than the radius R of curvature of the virtual surface 90, respectively. That is, r1 <R and r2 <R. 9 and 10, the radius of curvature r1 of the first protrusion 30b-1 and the radius of curvature r2 of the second protrusion 30b-2 are equal. That is, r1 = r2. Further, in the cross section perpendicular to the axial direction, the first protrusion 30b-1 and the second protrusion 30b-2 are inscribed in the virtual surface 90, respectively. Note that r1 ≠ r2 may be satisfied.

The magnetic flux in the air gap 1 between the rotor 2b and the stator 3 is provided by providing the first projecting portion 30b-1 and the second projecting portion 30b-2 whose cross section perpendicular to the axial direction has an arc shape. The density waveform can be approximated to a sine wave. Therefore, the torque ripple generated by the second modification 200b of the rotating electric machine can be reduced more than that by the first modification 200a of the rotating electric machine.

10, in the circumferential range occupied by the hole 11a, the radial distance from the permanent magnet 50 in the armature-side field core portion 22a-1 facing one of the magnetic poles 51-1 becomes the maximum. , The length of a straight line connecting the one magnetic pole 51-1 and the other magnetic pole 52-1 facing the other magnetic pole 52-1 and the point at which the radial distance from the permanent magnet 50 in the armature side field iron core portion 22a-1 is maximum. The width of the opening is Wh2. The definition of Wmag is the same as in FIG.

At this time, the opening width Wh2 is preferably set smaller than the magnetic pole width Wmag and larger than the minimum length g of the gap 1. That is, it is desirable to set the radius of curvature r1 of the first protrusion 30b-1 and the radius of curvature r2 of the second protrusion 30b-2 so that g <Wh2 <Wmag. This is because, in FIG. 10, when the hole 11a has a size that is not sufficient to prevent the magnetic flux 20 from flowing through the path C of the magnetic flux 20 that short-circuits the magnetic pole 51-1 and the magnetic pole 52-1, that is, the magnetic pole When the magnetic resistance of the path C of the magnetic flux 20 that crosses the extension of the boundary 10-1 is low, the magnetic flux 20 from the magnetic pole 51-1 passes through the path C of the magnetic flux 20 and is short-circuited to the adjacent magnetic pole 52-1. This is because the torque generated by the second modification 200b of the rotating electric machine may be reduced. When g <Wh2, the magnetic flux 20 flowing through the magnetic poles 51-1 and 52-1 is more likely to pass through the gap 1 than the opening width Wh2. When Wh2 <Wmag, the range in which the opening width Wh2 and the magnetic poles 51-1 and 52-1 overlap in the circumferential direction is smaller than the magnetic pole width Wmag. Therefore, it is possible to prevent the length of the air gap 1 through which the magnetic flux 20 of the magnetic poles 51-1 and 52-1 passes in the circumferential range of the hole 11a from expanding beyond the minimum length g. Therefore, it is possible to prevent the magnetic resistance in the air gap 1 from increasing and the magnetic flux 20 from becoming difficult to flow into the stator 3. Due to this dimensional relationship, the magnetic flux density in the gap 1 between the rotor 2b and the stator 3 can be efficiently increased, and the torque generated by the second modification 200b of the rotating electric machine can be further increased. Becomes

Further, in FIG. 10, the width in the radial direction that is the direction from the permanent magnet 50-1 to the stator 3 at the position of the adjacent surface 24 in the armature side field iron core portion 22a-1 is th2, and the armature side field magnet is In the iron core portion 22a-1, the minimum width in the direction from the circumferential end of the permanent magnet 50-1 toward the stator 3 is tb. Further, the portion of the rotor core 15b in the same range as the circumferential range of the hole 11a, including the portion having the width th2 in the armature side field core portion 22a-1, is the first bridge portion, that is, the thin portion 13a, Let th2 be the width of the thin portion 13a. Further, from the flux barrier 7 from the portion having the minimum width tb at the boundary of the armature side field iron core 22a-1 to the minimum width tb at the boundary of the armature side field iron core 22a-2 adjacent in the circumferential direction. Also, the portion of the rotor core 15b located on the stator 3 side is referred to as the second bridge portion 26a.

In order to cause magnetic saturation in the thin portion 13a, it is desirable to set the width th2 of the thin portion 13a as small as possible. That is, the width th2 of the thin portion 13a is preferably tb ≦ th2 <Wh2 / 2 with respect to the minimum width tb and the opening width Wh2. This is because the lower limit value of the width th2 of the thin portion 13a is set to the minimum width tb having the strength required to hold the centrifugal force generated in the permanent magnet 50-1 by the rotation of the rotor 2b, or the size that allows the electromagnetic steel plate to be punched. This is because it is necessary to set the minimum width tb. When th2 <Wh2 / 2, of the magnetic flux 20 flowing through the magnetic poles 51-1 and 52-1, the amount of magnetic flux passing through the width th2 of the thin portion 13a flows from the opening width Wh2 into the gap 1. This is because it is smaller than the amount of magnetic flux. Due to this dimensional relationship, magnetic saturation easily occurs in the thin portion 13a due to the magnetic flux 20 generated by the permanent magnet 50-1 or the magnetic flux generated by the stator 3. When magnetic saturation occurs in the thin portion 13a, the relative permeability of the thin portion 13a is close to that of air. Therefore, the torque generated by the second modification 200b of the rotary electric machine can be further increased.

Note that g <Wh2 <Wmag and tb ≦ th2 <Wh2 / 2 are dimensions that can be set individually, and the effect of increasing torque is also achieved. Further, if g <Wh2 <Wmag and tb ≦ th2 <Wh2 / 2, the torque generated by the second modification 200b of the rotating electric machine is increased as compared with the case of setting in any dimensional relationship.

In FIG. 9, the notch 23a formed at the position of the central surface 25, which is the surface located at the center in the circumferential direction between the permanent magnets 50-1 and 50-2 adjacent to each other in the circumferential direction, The virtual surface 90 may be filled with the rotor core 15b. When the hole 11a recessed from the virtual surface 90 toward the permanent magnets 50-1 and 50-2 is formed in the armature side magnetic field core 22a-1, the armature side field in which the hole 11a is formed is formed. The shape of the cross section perpendicular to the axial direction of the magnetic core portion 22a-1 is a shape in which two arcs are continuous in the circumferential direction. Therefore, the harmonic component of the magnetic flux density waveform of the air gap 1 in the circumferential range of the hole 11a between the rotor 2b and the stator 3 can be reduced, and the magnetic flux density waveform of the air gap 1 can be approximated to a sine wave. . Therefore, the second modification 200b of the rotating electric machine can reduce the torque ripple more than the rotating electric machine 200 of FIG.

Embodiment 3.
As an example in which the shape of the hole 11 of FIG. 3 is different, four modified examples of the rotary electric machine according to Embodiment 3 of the present invention will be described.

FIG. 11 is a partial cross-sectional view of a third modified example of the electric machine according to the third embodiment for carrying out the present invention. 11, a third modification 200c of the rotary electric machine that is an electric machine is different from the rotary electric machine 200 according to the first embodiment in the following points.
11, the shape of the cross section perpendicular to the axial direction of the hole 11 of FIG. 3 is a wedge shape, while the shape of the hole 11b of the third modification 200c of the rotating electric machine that is an electric machine is perpendicular to the axial direction. The shape of the cross section is a trapezoidal shape in which one apex portion of the triangular shape is cut by the virtual surface 90. The triangular vertex, which is the cross-sectional shape of the hole 11b, is in the void 1 at the position of the adjacent surface 24 of the rotor core 15c. Therefore, the outer circumference of the rotor core 15c on the adjacent surface 24 is opened toward the stator 3 by the opening width Wh3 in the circumferential direction. Here, in the circumferential range occupied by the hole 11 b, the radial distance from the permanent magnet 50 in the armature side field core portion 22 b facing the one magnetic pole 51 is the maximum, and the one magnetic pole 51. The opening width, which is the length of the straight line connecting the point in the armature side field iron core portion 22b facing the other magnetic pole 52 adjacent to, at the maximum radial distance from the permanent magnet 50, is Wh3. Further, in the armature-side field core portion 22b, a thin portion 13b which is a first bridge portion and is disposed so as to extend over the position of the adjacent surface 24 in the circumferential direction. The thin portion 13b, which is the first bridge portion, is a portion of the rotor core 15c in the same range as the circumferential range of the hole 11b, including the portion having the width th3 in the armature side field core portion 22b. Has a width of Whm3. The width th3 of the thin portion 13b in the direction from the permanent magnet 50 to the stator 3 is constant in the circumferential direction in the range of Whm3. In FIG. 11, Wh3 <Whm3.

When the opening width Wh1 and the opening width Wh3 of the hole portion 11 of FIG. 3 are the same length and the width th1 of the thin portion 13 and the width th3 of the thin portion 13b are the same length, the width th3 of the thin portion 13b. Is constant in the circumferential direction within the circumferential width Whm3 of the thin portion 13b, the length of the path D of the magnetic flux 20 is longer than the length of the path B of the magnetic flux 20 in FIG. Therefore, the magnetic resistance of the path D of the magnetic flux 20 becomes larger than the magnetic resistance of the path B of the magnetic flux 20 of FIG. For this reason, the magnetic flux density increases on the outer peripheral side of the rotor core 15c and magnetic saturation easily occurs, so that the short circuit of the magnetic flux 20 in the thin portion 13b is suppressed. Therefore, the torque of the third modification 200c of the rotary electric machine of FIG. 11 is increased as compared with the case of the rotary electric machine 200 of FIG.

FIG. 12 is a partial cross-sectional view of a fourth modified example of the electric machine according to the present embodiment. In FIG. 12, a fourth modification 200d of the rotary electric machine that is an electric machine is different from the third modification 200c of the rotary electric machine according to the present embodiment in the following points.
In FIG. 12, the opening width Wh4 of the hole portion 11c and the circumferential width Whm4 of the thin portion 13c are equal. That is, the shape of the cross section perpendicular to the axial direction of the hole 11c in the fourth modification 200d of the rotating electric machine is a rectangular shape, that is, a rectangular shape. When the circumferential width Whm4 of the thin portion 13c and the circumferential width Whm3 of the thin portion 13b of the hole 11b of FIG. 11 are equal, the opening width Wh4 is the opening width of the third modification 200c of the rotating electric machine. It becomes larger than Wh3.

Since the opening width Wh4 is larger than the opening width Wh3 of the third modification 200c of the rotating electric machine, the magnetic resistance that the magnetic flux 20 passes through the opening width Wh4 is the same as the opening width Wh3 of the third modification 200c of the rotating electric machine. It increases more than the reluctance it passes through. Therefore, in the fourth modification 200d of the rotating electric machine, the magnetic flux 20 flowing from the armature side field core portion 22c of the rotor core 15d to the stator 3 leaks to the opening width Wh4 in the third modification example of the rotating electric machine. It can be suppressed more than in the case of 200c. Therefore, the torque generated by the fourth modification 200d of the rotating electric machine is larger than that in the case of the third modification 200c of the rotating electric machine of FIG. 11.

When the circumferential width Whm4 of the thin portion 13c and the circumferential width Whm3 of the thin portion 13b of the hole 11b of FIG. 11 are equal, and when the sectional shape of the hole 11b of FIG. 10 is triangular. For the same reason, the torque generated by the fourth modification 200d of the rotating electric machine is higher than that of the rotating electric machine 200 of FIG.

Further, in the case of the hole 11c of FIG. 12, the magnetic flux density waveform generated in the gap 1 becomes a waveform closer to a sine wave shape than in the case of the hole 11b of FIG. This is because in the fourth modification 200d of the rotating electric machine, the magnetic flux 20 flowing from the armature side field iron core portion 22c to the stator 3 leaks to the opening width Wh4 more than in the case of the third modification 200c of the rotating electric machine. This is because it can be suppressed. Therefore, the harmonic component of the magnetic flux density waveform of the void 1 in the circumferential range of the hole 11c becomes smaller than that in the case of the hole 11b in FIG. Therefore, the torque ripple generated by the fourth modification 200d of the rotating electric machine is reduced as compared with the case of the third modification 200c of the rotating electric machine.

FIG. 13 is a partial cross-sectional view of a fifth modified example of the electric machine according to the present embodiment. In FIG. 13, a fifth modification 200e of the rotary electric machine that is an electric machine is different from the fourth modification 200d of the rotary electric machine according to the present embodiment in the following points.
13, in the armature-side field core portion 22d of the rotor core 15e, a recess 12 that is recessed from the magnet insertion hole 19 toward the stator 3 is formed at the position of the adjacent surface 24. The circumferential width Whm5 of the thin portion 13d, which is the first bridge portion between the recess 12 and the hole 11d, is equal to the opening width Wh5 and the circumferential opening width Wo1 of the recess 12. Further, the thin portion 13d is separated from the permanent magnet 50 with a predetermined length Do1 in the radial direction. The shape of the cross section perpendicular to the axial direction of the recess 12 in the fifth modification 200e of the rotating electric machine is a rectangular shape, that is, a rectangular shape.

Since the recess 12 is formed and the thin portion 13d is spaced apart from the permanent magnet 50 in the radial direction with a length Do1, the length of the path E of the magnetic flux 20 passing through the thin portion 13d is the fourth modification of the rotating electric machine. It becomes larger than the length of the path D of the magnetic flux 20 of 200d. Therefore, the magnetic resistance in the thin portion 13d is higher than the magnetic resistance in the thin portion 13d of the fourth modification 200d of the rotating electric machine. Therefore, in the fifth modification 200e of the rotating electric machine, the magnetic flux 20 flowing from the armature side field iron core portion 22d to the stator 3 leaks to the thin portion 13d more than in the fourth modification 200d of the rotating electric machine. Can be suppressed. Therefore, the torque generated by the fifth modification 200e of the rotating electric machine is larger than that in the case of the fourth modification 200d of the rotating electric machine.

FIG. 14 is a partial cross-sectional view of a sixth modified example of the electric machine according to the present embodiment. In FIG. 14, a sixth modification 200f of the rotary electric machine that is an electric machine is different from the fourth modification 200d of the rotary electric machine according to the present embodiment in the following points.
In FIG. 14, the hole 11 e penetrates from the void 1 to the magnet insertion hole 19. When the opening width of the hole 11e is Wh6, the hole 11e penetrates from the void 1 to the magnet insertion hole 19 with a width of the opening width Wh6. The hole 11e has a shape obtained by removing the thin portion 13c from the hole 11c of the fourth modification 200d of the rotary electric machine.

When the opening width Wh6 of the hole 11e of FIG. 14 is equal to the opening width Wh4 of the hole 11c of the fourth modification 200d of the rotating electric machine, the magnetic resistance through which the magnetic flux 20 passes through the opening width Wh6 is the fourth modification of the rotating electric machine. It is larger than the magnetic resistance in the thin portion 13c of Example 200d. Therefore, in the sixth modified example of the rotating electric machine, the magnetic flux 20 flowing from the armature-side field core portion 22e of the rotor core 15f to the stator 3 leaks to the opening width Wh6 in the fourth modified example of the rotating electric machine. This can be suppressed more than in the case of leakage to the thin portion 13c at 200d. Therefore, the torque generated by the sixth modification 200f of the rotating electric machine is higher than that in the case of the fourth modification 200d of the rotating electric machine.

Further, in the case of the hole 11e, the magnetic flux density waveform generated in the void 1 has a waveform closer to a sine wave shape than in the case of the hole 11c of FIG. This is because in the sixth modification 200f of the rotating electric machine, the magnetic flux 20 flowing from the armature side field iron core portion 22e to the stator 3 leaks to the opening width Wh6 more than in the case of the fourth modification 200d of the rotating electric machine. This is because it can be suppressed. For this reason, the harmonic component of the magnetic flux density waveform of the void 1 in the circumferential range of the hole 11e becomes smaller than that in the case of the hole 11c in FIG. Therefore, the torque ripple generated by the sixth modification 200f of the rotating electric machine is reduced as compared with the case of the fourth modification 200d of the rotating electric machine.

Fourth Embodiment
FIG. 15 is a partial cross-sectional view of a seventh modified example of the electric machine according to the fourth embodiment for carrying out the present invention. In FIG. 15, a seventh modification 200g of the rotating electric machine is different from the rotating electric machine 200 according to the first embodiment in the following points.

15, in the permanent magnet 50a-1, magnetic poles 51a and 52a having different poles on the side of the stator 3 are adjacent to each other in the circumferential direction, and four different poles are alternately arranged side by side in the circumferential direction. That is, in FIG. 15, the magnetic pole 51a is magnetized so that it has an N-pole on the surface on the side of the stator 3, and the magnetic pole 52a has an S-pole on the surface on the side of the stator 3. Therefore, in FIG. 15, on the surface of the permanent magnet 50a-1 on the side of the stator 3, the N pole of the magnetic pole 51a extends from the left end that is one end in the circumferential direction to the right end that is the other end in the circumferential direction. It is formed in parallel with the pole, the S pole of the magnetic pole 52a, the N pole of the magnetic pole 51a, and the S pole of the magnetic pole 52a. Further, also in the permanent magnet 50a-2 circumferentially adjacent to the permanent magnet 50a-1, the N pole of the magnetic pole 51a and the S pole of the magnetic pole 52a from the one end in the circumferential direction to the other end in the circumferential direction. , The N pole of the magnetic pole 51a and the S pole of the magnetic pole 52a. Further, in the surface where the magnetic poles 51a and 52a are adjacent to each other in the circumferential direction, the magnetic pole boundaries 10a-1 and 10a-2 are directed from the left end which is one end in the circumferential direction to the right end which is the other end in the circumferential direction in FIG. 10a-3. Similarly, the permanent magnets 50a-3 (not shown) are adjacent to each other in the circumferential direction of the permanent magnet 50a-2, and the permanent magnets 50a-4 are adjacent to each other in the circumferential direction of the permanent magnet 50a-3.

Note that in FIG. 15, there are four magnetic poles per one of the permanent magnets 50a-1 to 50a-4 and four permanent magnets 50a-1 to 50a-4. The total number of magnetic poles 51a and 52a appearing in the void 1 is 16. Therefore, the rotary electric machine 200g is a rotary electric machine having 16 magnetic poles and 12 slots 21.

In FIG. 15, the surfaces including the magnetic pole boundaries 10a-1, 10a-2, and 10a-3, which are the surfaces where the magnetic poles 51a and 52a are adjacent to each other, are referred to as adjacent surfaces 24a-1, 24a-2, and 24a-3, respectively. In the armature side field iron core portion 22f of the rotor iron core 15g, the hole portions 11f-1, 11f-2, 11f-3 recessed from the virtual surface 90 toward the permanent magnet 50a-1 are respectively formed on the adjacent surface 24a-1. , 24a-2, 24a-3.

In FIG. 15, one of the permanent magnets 50a-1 to 50a-4 is provided with four magnetic poles 51a and 52a, which are a plurality of magnetic poles. When the total number of magnetic poles of the rotor is 16, which is the same as the total number of magnetic poles 51a and 52a in the present embodiment, the number of magnet insertion holes formed in the rotor and the number of permanent magnets are the same as those of magnetic poles 51a and 52a. It is assumed that the rotating electrical machine of the fourth comparative example is 16 which is the same as the total number. Except for the number of magnet insertion holes and the number of permanent magnets, the rotating electrical machine of the third comparative example has the same configuration.

In the seventh modification 200g of the rotating electric machine of the present embodiment, the number of magnet insertion holes 19 or permanent magnets 50a-1 to 50a-4 is 16 which is the number of permanent magnets of the rotating electric machine of the fourth comparative example. , The number of the magnetic poles 51a and 52a formed in one of the permanent magnets 50a-1 to 50a-4 is four, which is the number divided by four. Therefore, the number of man-hours required to shape the permanent magnets 50 of the rotary electric machine 200 of the present embodiment is ¼ that of the rotary electric machine of the fourth comparative example. Similarly, the man-hours for magnetizing the seventh modification 200g of the rotating electric machine and the man-hours for inserting the permanent magnets 50a-1 to 50a-4 into the magnet insertion holes 19 are also 1/4 of those of the rotating electric machine of the fourth comparative example. become. Therefore, the manufacturing cost of the seventh modification 200g of the rotating electric machine can be reduced as compared with the rotating electric machine of the fourth comparative example. Further, the manufacturing cost of the seventh modified example 200g of the rotating electric machine can be reduced as compared with the rotating electric machine 200 of FIG.

Note that, in FIG. 15, the number of magnetic poles 51a and 52a formed on one permanent magnet 50a-1 to 50a-4 is not limited to four poles, and may be an odd number of magnetic poles such as three poles and five poles. The number of magnetic poles 51a and 52a in one permanent magnet 50a-1 to 50a-4 may be three or more.

When the magnetic pole width of the magnetic poles 51a and 52a in contact with any of the adjacent surfaces 24a-1 to 24a-3 is Wmag, g <Wh1 <Wmag or tb ≦ th1 <Wh1 / as in the first embodiment. If 2 is satisfied, the torque increases even in the seventh modification 200g of the rotating electric machine of the present embodiment.

Embodiment 5.
FIG. 16 is a partial cross-sectional view of an eighth modified example of the electric machine according to the fifth embodiment for carrying out the present invention. In FIG. 16, an eighth modification 200h of the rotary electric machine differs from rotary electric machine 200 according to Embodiment 1 in the following points.

In FIG. 16, in an eighth modification 200h of the rotary electric machine according to the present embodiment, the permanent magnet 50b has two cylindrical surfaces 53-1 and 53-2 that are opposed to each other in the radial direction. The cylindrical surfaces 53-1 and 53-2 are arranged in a direction including the direction from the permanent magnet 50b toward the stator 3 and a circumferential direction, that is, in a cross section perpendicular to the axial direction, in the direction from the permanent magnet 50b toward the stator 3, respectively. It is convex. The surface of the permanent magnet 50b on which the poles of the magnetic poles 51 and 52 are formed is one cylindrical surface 53-1 on the outer diameter side, that is, the stator 3 side. The radial width of the permanent magnet 50b in FIG. 16 is constant in the circumferential direction. Therefore, the radius of curvature of the outer diameter side cylindrical surface 53-1 is larger than the radius of curvature of the inner diameter side cylindrical surface 53-2 by the radial width of the permanent magnet 50b.

Since the cylindrical surfaces 53-1 and 53-2 are convex in the direction perpendicular to the axial direction from the permanent magnet 50b toward the stator 3, the harmonic components of the magnetic flux density waveform of the air gap 1 can be reduced. , The magnetic flux density waveform of the air gap 1 can be approximated to a sine wave. Therefore, the eighth modification 200h of the rotating electric machine can reduce the torque ripple more than the rotating electric machine 200.

Since the permanent magnet 50b in the eighth modified example 200h of the rotating electric machine has two cylindrical surfaces 53-1 and 53-2 that face each other in the radial direction, there is a gap with the cylindrical surface 53-1 on the stator 3 side. The radial distance to 1 is shortened. Further, the radial width of the armature side field core portion 22g of the rotor core 15h can be reduced. Therefore, the magnetic resistance of the path F of the magnetic flux 20 is higher than the magnetic resistance of the path B of the magnetic flux 20 of the rotary electric machine 200. Therefore, the short circuit of the magnetic flux 20 flowing through the path F can be suppressed more than in the case of the rotary electric machine 200 in FIG. Therefore, the eighth modification 200h of the rotary electric machine according to the present embodiment can obtain a larger torque than that of the rotary electric machine 200.

In the rotor of the rotating electric machine of the present invention, the hole portions 11, 11b to 11e in FIGS. 3, 10 to 16, the cutout portions 23 and 23a in FIGS. 8 and 10 and the permanent magnets in FIGS. 50, 50a-1 to 50a-4, 50b may be arbitrarily combined. With these configurations as well, similar to the case of the rotary electric machine 200 according to the first embodiment, the torque ripple generated by the rotary electric machine is connected to the outer peripheral portion of the armature-side field core portion on the stator side. Is less than.

When the magnetic pole width, which is the width in the circumferential direction perpendicular to the magnetizing direction corresponding to one pole of the magnetic poles 51 and 52, is Wmag, that is, in FIG. 16, one end of the magnetic poles 51 and 52 are adjacent to each other. When the magnetic pole width, which is the distance from the surface 24 to the other ends of the magnetic poles 51 and 52, is Wmag, if g <Wh1 <Wmag or tb ≦ th1 <Wh1 / 2 is satisfied as in the first embodiment, the present embodiment is performed. The torque also increases in the eighth modification 200h of the rotating electric machine of the form.

Sixth Embodiment
FIG. 17 is a perspective view of a rotor of a ninth modification of the electric machine according to the sixth embodiment for carrying out the present invention. FIG. 18 is a GG sectional view of FIG. 17 of the ninth modification of the electric machine according to the present embodiment. Since the stator of the ninth modification 200i of the rotating electric machine that is the electric machine in the present embodiment is the same as the stator 3 of the rotating electric machine 200 according to the first embodiment, the rotation shown in FIGS. The stator of the ninth modification 200i of the electric machine is not shown for convenience. 17 and 18, a ninth modification 200i of the rotary electric machine differs from rotary electric machine 200 according to Embodiment 1 in the following points.

In FIG. 17, the rotor core 15i in the ninth modification 200i of the rotating electric machine is arranged in a direction perpendicular to the direction from the permanent magnet 50 to the stator 3 and the circumferential direction, that is, in a partial range in the axial direction. It has the 1st field 40 and the 2nd field 41 arranged in the range of the direction of an axis different from the range of the 1st field 40. The hole 11e shown in FIG. 14 of the third embodiment is arranged in the first region 40. In the second region 41, the rotor iron core 15i exists from the magnet insertion hole 19 to the virtual surface 90 at the position of the adjacent surface of the armature side field iron core portion 22h-2. That is, in the second region 41, no hole is formed in the armature side field iron core portion 22h-2, and the magnet insertion hole 19 to the virtual surface 90 are connected by the magnetic steel plate which is a magnetic body. In the rotor core 15i of FIG. 17, one second region 41 is arranged at each of both ends in the axial direction, and the first region is provided at the center of the rotor 2i between the two second regions 41 in the axial direction. 40 is connected to the second region 41 to form the rotor 2i. In the rotor core 15i of FIG. 17, the total axial length of the two second regions 41 is equal to the axial length of the first region 40.

The cross section perpendicular to the axial direction of the first region 40 is the cross section shown in FIG. The cross section perpendicular to the axial direction of the second region 41 is the cross section shown in FIG. 18. 18, in the armature side field iron core portion 22h-2 of the second region 41, an electromagnetic steel plate which is a magnetic body exists at the position of the adjacent surface 24 corresponding to the hole 11e of FIG. That is, the armature side field core portion 22h-2 corresponding to the hole 11e is filled with the electromagnetic steel plate. Therefore, in the armature side field iron core portion 22h-2, the magnetic flux 20 is short-circuited through the path H of the magnetic flux 20 between the magnetic pole 51 and the magnetic pole 52. Therefore, the magnetic resistance that short-circuits between the magnetic pole 51 and the magnetic pole 52 in the first region 40 due to the hole 11e in the first region 40 is higher than that in the second region 41.

In the ninth modification 200i of the rotating electric machine, the first region 40 having the armature side field iron core portion 22h-1 in which the hole 11e is formed and the armature side field iron core portion in which the hole 11e is not formed. Due to the structure in which the second region 41 having 22h-2 is axially connected, the rotor 2i as a whole suppresses the decrease in strength against centrifugal force due to the hole 11e in the first region 40 in the second region 41. Short-circuiting of the magnetic flux 20 between the magnetic pole 51 and the magnetic pole 52 in the second region 41 can be suppressed more than in the case where the second region 41 is used in the first region 40 in the axial direction. Can be suppressed. Further, by disposing the second regions 41 in which the strength of the rotor 2i against the centrifugal force is larger than that in the first region 40 at both ends in the axial direction, both axial ends of the first region 40 can be fixed, and the rotor can be fixed. The strength against the centrifugal force of 2i can be improved as compared with the case of only the first region 40.

Note that, in FIG. 18, the first region 40 in which the hole 11e is formed is provided at only one position in the axial direction, but the present invention is not limited to this, and the first region 40 and the second region 41 are alternately connected in the axial direction. Then, the rotor core 15i may be configured. In that case, each of the first region 40 and the second region 41 may be formed by laminating several electromagnetic steel plates. Further, the sum of the axial lengths of the two second regions 41 and the axial length of the first region 40 may be different depending on the required strength against the centrifugal force.

FIG. 19 is a perspective view of a rotor of a tenth modified example of the electric machine according to the present embodiment. In FIG. 19, a tenth modification 200j of the rotary electric machine is different from the ninth modification 200i of the rotary electric machine according to the present embodiment in the following points.
A cross section of the first region 40a perpendicular to the axial direction is the cross section shown in FIG. 5 of the first embodiment. That is, the concave portion 312 shown in FIG. 5 of the first embodiment is arranged in the first region 40a. The concave portion 312 is formed in the armature side field core portion 22i-1 of the rotor core 15j.
The cross section perpendicular to the axial direction of the second region 41a is the cross section shown in FIG. 3 of the first embodiment. That is, the hole 11 shown in FIG. 3 of the first embodiment is arranged in the second region 41a. The hole 11 is formed in the armature side field core 22i-2 of the rotor core 15j.

In the tenth modified example 200j of the rotating electric machine, the first region 40a in which the concave portion 312 is arranged and the second region 41a in which the hole 11 is arranged are axially connected to each other, so that the rotor 2j as a whole is It is possible to suppress an increase in torque ripple in the first region 40a in the second region 41a while suppressing a decrease in the strength of the rotor 2j with respect to the centrifugal force due to the concave portion 312 in the first region 40a in the second region 41a. Further, by disposing the second regions 41a at both ends in the axial direction in which the strength of the rotor 2j against the centrifugal force is larger than that in the first region 40a, the radial direction due to the centrifugal force at both axial ends of the first region 40a. Can be suppressed, and the strength of the rotor 2j against the centrifugal force can be improved as compared with the case of only the first region 40a.

Note that, in FIG. 19, the first region 40a in which the hole portion 11 is formed is only one position in the axial direction, but the present invention is not limited to this, and the first region 40 and the second region 41a are alternately connected in the axial direction. Then, the rotor core 15j may be configured. In that case, each of the first region 40a and the second region 41a may be formed by laminating several electromagnetic steel plates. In addition, the sum of the axial lengths of the two second regions 41a and the axial length of the first region 40a may be different depending on the required strength against the centrifugal force.

The cross sections perpendicular to the axial direction of the first regions 40, 40a and the second regions 41, 41a are not limited to the cross sections shown in FIGS. 3, 5, 14, and 18, but the hole portion 11 in FIGS. , 11b to 11e, the cutout portions 23 and 23a in FIGS. 8 and 10 and the permanent magnets 50, 50a-1 to 50a-4 and 50b in FIGS. Good. In the combination of these cross sections, for example, if a cross section having large strength against centrifugal force as shown in FIGS. 3 and 18 is arranged at the end portion in the axial direction, the strength of the rotor against centrifugal force can be improved.

Embodiment 7.
FIG. 20 is a partial cross-sectional view of an eleventh modified example of the electric machine according to the seventh embodiment for carrying out the present invention. 20, a direct acting machine 200k that is an eleventh modified example of the electric machine according to the present embodiment is different from the rotary electric machine 200 according to the first embodiment in the following points. The cross-sectional view is a cross-sectional view on a plane including the X direction that is along the linear movement direction of the linear motor 200k and the Y direction that is along the direction from the field to the armature. In FIG. 20, the direction perpendicular to the paper surface is the Z direction.

In FIG. 20, a linear motor 200k according to the present embodiment has a structure in which the rotary electric machine 200 of FIG. 2 is linearly expanded in the X direction. Specifically, the linear motor 200k includes a mover 103 that is an armature and a stator 102 that is a field. The mover 103 is supported by a linear guide (not shown) so as to be linearly movable. The bottom surface of the stator 102, which is the surface of the stator 102 opposite to the movable element 103 side, is fixed to the upper surface of the base 109. With these configurations, the mover 103 moves linearly along the linear guide. That is, the stator 102, which is a field, faces the mover 103 via the air gap 101 and is movable in the X direction relative to the mover 103, that is, in the X direction relative to the mover 103. It is arranged so that it can move linearly.

In FIG. 20, the mover 103 includes a mover core 116, which is an armature core, and six windings 106. The mover iron core 116 includes a linear core back portion 117 and six teeth portions 118 protruding from the core back portion 117 toward the stator 102 and arranged at equal intervals in the linear movement direction, that is, the X direction. Have. For the purpose of reducing the eddy current, the mover iron core 116 has a plurality of sheet-like mover iron core sheets 116-1 punched in the same shape from an electromagnetic steel sheet in a predetermined Z direction perpendicular to the X and Y directions. It is constructed by stacking the lengths. The teeth portion 118 of the mover iron core 116 is arranged so as to face the stator 102 via the gap 101. Six slots 121 are formed between the teeth portions 118 adjacent to each other in the X direction. The six windings 106 are wound around the teeth 118 via the insulators 108, and are housed in the six slots 121, respectively. The winding 106 is composed of two windings 106 for each phase and a total of six windings 106 for three phases. Two windings 106 for each phase are connected in series to form a phase winding group, and the phase winding group for three phases is Y-connected. When a three-phase AC current is applied to each phase winding group having the winding 106 from the inverter 100, which is a power converter (not shown), with a phase difference of 120 ° between the phases, a magnetic field that linearly moves in the X direction is generated. The mover 103 generates the air gap 101, and the stator 102 generates thrust in the X direction. The method of connecting the three-phase phase winding group is not limited to Y connection and may be Δ connection.

The stator 102 has a plurality of permanent magnets 150 and a stator core 115 which is a field core in which the plurality of permanent magnets 150 are embedded. The stator core 115 is configured by stacking a plurality of sheet-shaped stator core sheets 115-1 punched from an electromagnetic steel plate in the same shape in a predetermined length in the Z direction. In the stator core 115, magnet insertion holes 119 into which the permanent magnets 150 are inserted are formed in the same number as the permanent magnets 150 at equal intervals in the X direction. One permanent magnet 150 is inserted into each of the plurality of magnet insertion holes 119. In FIG. 20, for convenience, two permanent magnets 150 and two magnet insertion holes 119 are shown, but two or more permanent magnets 150 are arranged side by side, and the length of the stator 102 in the X direction is equal. The stroke length is the length of the movable range required by the mover 103.

At both ends of the magnet insertion hole 119 in the linear movement direction, short-circuiting of magnetic flux between the permanent magnets 150 inserted in the magnet insertion holes 119 adjacent to each other in the linear movement direction is suppressed, and flux barriers are holes that penetrate in the Z direction. 107 is provided. A non-magnetic material such as resin may be inserted in the flux barrier 107.

In the permanent magnet 150, magnetic poles 151 and 152 having different poles are formed adjacent to each other in the X direction on the side of the mover 103, which is an armature. That is, in FIG. 1, the magnetic pole 151 is magnetized so as to have an N-pole on the surface on the mover 103 side and the magnetic pole 152 to have an S-pole on the surface on the mover 103 side. The N pole of the magnetic pole 151 is formed on the surface on the side of the mover 103 on the one side in the X direction from the center of the permanent magnet 150. The S pole of the magnetic pole 152 is formed on the surface on the side of the mover 103 on the other side in the X direction from the center of the permanent magnet 150. A surface where the magnetic poles 151 and 152 are adjacent to each other in the X direction is a magnetic pole boundary 110. Here, the definition of the magnetic pole boundary 110 is the same except that the circumferential direction in the first embodiment is replaced with the X direction. Further, the permanent magnet 150 has the same flat plate shape as the permanent magnet 1 of FIG. 3 of the first embodiment.
In FIG. 20, a direct drive machine 200k is a direct drive machine having two or more magnetic poles 151 and 152 and six slots 121. Further, the number of magnetic poles 151 and 152 facing the X direction range of the mover 103 of the linear motor 200k is four.

In FIG. 20, the stator core 115 located closer to the mover 103 than the permanent magnet 150 is the armature side field core 122. A surface separated from the mover 103 in the direction toward the stator core 115 with a distance equal to the minimum length g of the gap 101 is defined as a virtual surface 190. In FIG. 20, a virtual surface 190 is a surface including the magnetic pole boundary 110, which is a surface where the magnetic poles 151 and 152 are adjacent to each other, and is referred to as an adjacent surface 124. In the armature side field iron core portion 122, a hole portion 111 that is recessed from the virtual surface 190 toward the permanent magnet 150 is formed at the position of the adjacent surface 124. Here, the minimum length g of the gap 101 represents the minimum distance in the Y direction between the teeth portion 118 of the mover core 116 and the stator core 115. The boundary of the armature side field iron core portion 122 is a portion of the stator iron core 115 that is the minimum width tb in the direction from the end of the permanent magnet 150 in the X direction toward the mover 103. In FIG. 20, an imaginary plane 190 is a plane separated from the mover 103 toward the stator core 115 with a minimum length g of the gap 101. In FIG. 20, the virtual surface 190 coincides with the surface of the stator core 115 on the mover 103 side.

The hole portion 111 is formed in the armature side field iron core portion 122, straddling the adjacent surface 124 in the X direction. The cross-sectional shape of the hole 111 in the cross section perpendicular to the Z direction is a wedge shape in which the width in the X direction is narrowed in the Y direction from the virtual surface 190 toward the permanent magnet 150 side to be convex.

With these configurations, as in the case of the rotary electric machine 200 according to the first embodiment, the thrust ripple of the linear motor 200k according to the present embodiment in FIG. 20 is generated by the outer peripheral portion of the armature side field core portion on the mover side. Is less than when connected.

20, in addition to the hole portion 111, a cutout portion 123 is also provided between the adjacent permanent magnets 150 on the outer peripheral portion of the stator core 115. That is, the notch 123 recessed from the virtual surface 190 in the direction from the mover 103 to the stator core 115 is located at the center of the stator core 115 in the X direction between the permanent magnets 150 adjacent to each other in the X direction. It is formed at the position of the central surface 125 which is the surface to be formed.

Further, in FIG. 20, in the range of the X direction occupied by the hole 111, in the Y direction, which is the direction from the permanent magnet 150 to the mover 103, the permanent magnet in the armature side field iron core 122 facing the one magnetic pole 151 is permanent. The point in which the Y-direction distance from the magnet 150 is maximum, and the distance in the Y-direction from the permanent magnet 150 in the armature side field core portion 122 facing the other magnetic pole 152 adjacent to the one magnetic pole 151 is maximum. The opening width, which is the length of the straight line connecting to the point, is Wh8, and the width in the moving direction, that is, the width in the X direction, which is the direction perpendicular to the magnetization direction corresponding to one pole of the magnetic pole 151 or the magnetic pole 152 of the permanent magnet 150. The width of the magnetic pole is Wmag. At this time, the opening width Wh8 is preferably set to be smaller than the magnetic pole width Wmag and larger than the minimum length g of the gap 101. That is, it is desirable that g <Wh8 <Wmag.

Further, in FIG. 20, in the armature side field iron core portion 122, the width in the Y direction which is the direction from the permanent magnet 150 to the mover 103 at the position of the adjacent surface 124 is th6, and the armature side field iron core portion 122 The minimum width in the direction from the end of the permanent magnet 150 in the X direction toward the mover 103 is tb. Further, the portion of the stator core 115 in the same range as the X direction range of the hole 111 including the portion having the width th6 in the armature side field iron core portion 122 is the first bridge portion, that is, the thin portion 113, and th6 is The width of the thin portion 113 is set. Further, the side closer to the mover 103 than the flux barrier 107 from the portion having the minimum width tb at the boundary of the armature side field iron core 122 to the minimum width tb at the boundary of the armature side field iron core 122 adjacent in the X direction. The portion of the stator core 115 located at is the second bridge portion 126.

In order to generate magnetic saturation in the thin portion 113, it is desirable to set the width th6 of the thin portion 113 as small as possible. That is, the width th6 of the thin portion 113 is preferably tb ≦ th6 <Wh8 / 2 with respect to the minimum width tb and the opening width Wh8. This is because it is necessary to set the lower limit value of the width th6 of the thin portion 113 to the minimum width tb of a dimension that allows the electromagnetic steel sheet to be punched. When th6 <Wh8 / 2, the amount of magnetic flux passing through the width th6 of the thin portion 113 among the magnetic flux 120 flowing through the magnetic poles 151 and 152 is greater than the amount of magnetic flux flowing from the opening width Wh8 into the air gap 101. Is also smaller. Due to this dimensional relationship, magnetic saturation easily occurs in the thin portion 113 due to the magnetic flux 120 generated by the permanent magnet 150 or the magnetic flux generated by the mover 103. When the magnetic saturation occurs in the thin portion 113, the relative permeability of the thin portion 113 is close to that of air. Therefore, the thrust generated by the linear motor 200k can be further increased.

Note that g <Wh8 <Wmag and tb ≦ th6 <Wh8 / 2 are dimensions that can be set individually, and the effect of increasing thrust is also achieved. Further, if g <Wh8 <Wmag and tb ≦ th6 <Wh8 / 2, the thrust is increased as compared with the case of setting either of the dimensional relationships.

FIG. 21 is a partial cross-sectional view of a twelfth modified example of the electric machine according to the present embodiment. In FIG. 21, a linear motor 200m that is a twelfth modified example of the electric machine according to the present embodiment is different from the linear motor 200k according to the present embodiment in the following points.
In FIG. 21, the hole portion 111a penetrates from the void 101 to the magnet insertion hole 119. When the opening width of the hole portion 111a is Wh9, the hole portion 111 penetrates from the gap 101 to the magnet insertion hole 119 with a width of the opening width Wh9.

When the opening width Wh9 of the hole portion 111a of FIG. 21 is the same as the opening width Wh8 of the hole portion 111 of the linear motor 200k, the magnetic resistance of the magnetic flux 120 passing through the opening width Wh9 is smaller than that of the thin portion 113 of the linear motor 200k. Also increases. Therefore, in the linear motor 200m, the magnetic flux 120 flowing from the armature-side field core portion 122a of the stator core 115a to the mover 103 leaks to the opening width Wh9 more than to the thin wall portion 113 of the linear motor 200k. Can be suppressed. Therefore, as in the case of the third embodiment, the thrust generated by the linear motor 200m is increased as compared with the case of the linear motor 200k.

In this embodiment, the movable wire 103 is a linear motor having a permanent magnet 150 as a field, which is a linear motor. However, the movable wire 103 is a stator, and the stators 102 and 102a are stators. It may be a magnet-movable linear motor that is a mover that moves with respect to. Further, the winding 106 may be arranged not on the mover 103 but on the stators 102 and 102a.

The cross-sectional shape of the hole 111 in the cross section perpendicular to the Z direction is not limited to the cross-section shown in FIGS. 20 and 21, and the hole 11 and 11b to 11e in FIGS. It may be a cross section in which the notch portions 23, 23a and the permanent magnets 50, 50a-1 to 50a-4, 50b in FIGS. 3, 15 and 16 are arbitrarily combined. With these configurations as well, as in the case of the linear motor 200k of the present embodiment of FIG. 20, the thrust ripple is greater than that in the case where the outer peripheral portion of the armature-side field core portion on the mover side is connected. Will be reduced.

Further, as in the ninth modified example 200i and the tenth modified example 200j of the rotating electrical machine of the sixth embodiment, cross sections of the stator cores 122, 122a in the linear motors 200k, 200m of the present embodiment perpendicular to the Z direction. The combination of two or more cross-sections in which any of the hole portions 11 to 11g in FIGS. 3, 4, 8 to 13, 15, 16, and 18 are formed in the armature side field core portions 122 and 122a in the Z direction. It may be configured by stacking.

1, 101, 301 air gap, 2, 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 302 rotor (field), 3,303 stator (armature), 4 support shaft , 5 bearings, 6, 106, 306 windings, 7, 107, 307 flux barrier, 8, 108, 308 insulators, 9 housing, 10, 10-1, 10-2, 10a-1, 10a-2, 10a- 3, 110, 310 magnetic pole boundary, 11, 11-1, 11-2, 11a, 11b, 11c, 11d, 11e, 11f-1, 11f-2, 11f-3, 11g, 111, 111a hole, through hole Parts (holes), 12, 312 recesses, 13, 13a, 13b, 13c, 13d, 113, 313 thin parts (first bridge part), 15, 15a, 5b, 15c, 15d, 15e, 15f, 15g, 15h, 15i, 15j, 315 rotor core (field core), 15-1 rotor core sheet, 16, 316 stator core (armature core), 16- 1 stator core sheet, 17, 117 core back part, 18, 118, 318 teeth part, 19, 19a, 119, 319 magnet insertion hole, 20, 120, 320 magnetic flux, 21, 121 slot, 22, 22-1, 22-2, 22a-1, 22a-2, 22b, 22c, 22d, 22e, 22f, 22g, 22h-1, 22h-2, 22i-1, 22i-2, 122, 122a, 322 Armature side magnetic field Iron core part, 23, 23a, 123 Notch part, 24, 124, 24-1, 24-2, 24a-1, 24a-2, 24 -3, 324 adjacent surface, 25, 325 central surface, 26, 26a, 126, 326 second bridge portion, 30a-1, 30a-2, 30b-1, 30b-2 protrusion (first protrusion, first 2 protrusions), 40, 40a first area, 41, 41a second area, 50, 50-1, 50-2, 50a-1, 50a-2, 50a-3, 50a-4, 50b, 150, 350 permanent magnets, 51, 51-1, 51-2, 51a, 52, 52-1, 52-2, 52a, 151, 152, 351, 352 magnetic poles (first magnetic pole, second magnetic pole), 53- 1, 53-2 cylindrical surface, 90, 190 virtual surface, 100 inverter (electric power converter), 102, 102a stator (field), 103 mover (armature), 109 base, 115, 115a Stator core (field core), 115-1, 115a-1, Stator core sheet, 116 Mover core (armature core), 116-1 Mover core sheet, 200, 200a, 200b, 200c, 200d, 200e , 200f, 200g, 200h, 200i, 200j Rotating electric machine (electric machine), 200k, 200m Direct acting machine (electric machine), 300 rotating electric machine (electric machine) 1st comparative example, 500 drive system.

Claims (17)

1. With an armature,
   A field magnet, which is arranged so as to face the armature via a gap and is movable relative to the armature, and magnetic poles having different poles on the armature side are formed adjacent to each other in the moving direction. And a field magnet having a field iron core in which the permanent magnet is embedded,
   When a surface away from the armature at a distance equal to the minimum length of the air gap in the direction toward the field core is a virtual surface,
   In the armature-side field iron core portion, which is the field iron core located closer to the armature than the permanent magnet, a hole recessed from the virtual surface toward the permanent magnet is a surface where the magnetic poles are adjacent to each other. An electric machine formed at the position of the adjacent surface including.
2. The field has a plurality of the permanent magnets,
   In the field iron core, a notch portion recessed from the virtual surface in a direction from the armature to the field iron core is located at a center of the moving direction between the permanent magnets adjacent to each other in the moving direction. The electric machine according to claim 1, wherein the electric machine is formed at a surface position.
3. When the permanent magnets adjacent to each other in the moving direction with the cutout portion interposed therebetween are the first permanent magnets and the second permanent magnets,
   In the armature side field iron core portion at a position of the adjacent surface including one end surface in the circumferential direction of the first magnetic pole closest to the cutout portion in the first permanent magnet, the first hole portion is provided. Has been formed,
   In the field core, a first protrusion that protrudes from the first permanent magnet toward the armature is formed between the first hole and the notch,
   In the armature side field iron core portion at the position of the adjacent surface including the circumferential one end surface of the second magnetic pole closest to the cutout portion in the second permanent magnet, the second hole portion is provided. Has been formed,
   The said field iron core WHEREIN: The 2nd protrusion part which protrudes toward the said armature from the said 2nd permanent magnet is formed between the said 2nd hole part and the said notch part. The electric machine described in.
4. The electric machine according to claim 3, wherein a radius of curvature of the first protrusion and a radius of curvature of the second protrusion are smaller than a radius of curvature of the virtual surface.
5. In the armature side field iron core portion, a bridge portion is formed which is arranged across the position of the adjacent surface in the movement direction,
   The electric machine according to any one of claims 1 to 4, wherein a width of the bridge portion in a direction from the permanent magnet to the armature is constant in the moving direction.
6. In the direction from the permanent magnet to the armature in the range of the moving direction occupied by the hole, the magnetic pole width that is the width of the magnetic pole of the permanent magnet in the moving direction is Wmag, the minimum length of the air gap is g. A point at which the distance from the permanent magnet in the armature side field iron core portion facing one of the magnetic poles is maximum and the armature side field iron core portion facing the other magnetic pole adjacent to the one magnetic pole. The opening width, which is the length of a straight line connecting the point at which the distance from the permanent magnet is maximum in Wh, from the permanent magnet to the armature at the position of the adjacent surface in the armature side field core portion When the width in the direction is th and the minimum width in the direction from the end of the permanent magnet in the moving direction toward the armature in the armature side field core is tb,
   The electric machine according to any one of claims 1 to 5, wherein g <Wh <Wmag or tb ≦ th <Wh / 2.
7. A magnet insertion hole in which the permanent magnet is embedded is formed in the field core,
   In the armature side field iron core part, a recessed portion that is recessed from the magnet insertion hole toward the armature side is formed at a position of the adjacent surface. The described electric machine.
8. A magnet insertion hole in which the permanent magnet is embedded is formed in the field core,
   The electric machine according to any one of claims 1 to 4, wherein the hole penetrates from the gap to the magnet insertion hole.
9. The electric machine according to any one of claims 1 to 8, wherein the number of the magnetic poles in the permanent magnet is 3 or more.
10. The electric machine according to any one of claims 1 to 9, wherein the permanent magnet is composed of one magnetic body having a plurality of the magnetic poles.
11. The electric machine according to any one of claims 1 to 9, wherein the permanent magnet is composed of a plurality of magnetic bodies divided for each magnetic pole.
12. The permanent magnet has two flat surfaces facing each other,
    The electric machine according to any one of claims 1 to 11, wherein a surface of the permanent magnet on which the pole is formed is one of the flat surfaces.
13. The permanent magnet has two cylindrical surfaces facing each other,
    The cylindrical surface is convex in a direction from the permanent magnet to the armature in a cross section including a direction from the permanent magnet to the armature and the moving direction,
    The electric machine according to any one of claims 1 to 11, wherein a surface of the permanent magnet on which the pole is formed is one of the cylindrical surfaces.
14. The field iron core has a first region arranged in a partial range in a direction perpendicular to the moving direction from the permanent magnet to the armature and a range different from the range of the first region. And a second region arranged,
    The hole is arranged in the first region,
    The electric machine according to claim 7, wherein the recess is arranged in the second region.
15. The field iron core has a first region arranged in a partial range in a direction perpendicular to the moving direction from the permanent magnet to the armature and a range different from the range of the first region. And a second region arranged,
    The hole is arranged in the first region,
    The electric machine according to claim 8, wherein the field iron core exists in the second region from the magnet insertion hole to the virtual surface at a position of the adjacent surface in the armature side field iron core portion.
16. The electric machine according to any one of claims 1 to 15, wherein the field rotates relative to the armature in the movement direction about an axis.
17. The electric machine according to any one of claims 1 to 15, wherein the field moves linearly relative to the armature in the movement direction.

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