JP7224986B2 - Rotating electric machine - Google Patents

Description

An embodiment of the present invention relates to a rotating electric machine.

In recent years, remarkable research and development of permanent magnets has led to the development of permanent magnets with a high magnetic energy product, and permanent magnet-type rotating electric machines using such permanent magnets are being applied as electric motors or generators for electric trains and automobiles. A permanent magnet type rotary electric machine usually includes a cylindrical stator and a cylindrical rotor rotatably supported inside the stator. The rotor has a rotor core and a plurality of permanent magnets embedded within the rotor core.
Under such circumstances, rotating electric machines with various structures for improving energy efficiency are being studied.

JP-A-2004-260920

This embodiment provides a rotating electrical machine with high energy efficiency. Alternatively, the present invention provides a rotating electrical machine capable of achieving high output.

A rotating electric machine according to one embodiment includes:
A stator having a stator core and coils, a rotor core having a plurality of embedded holes, a plurality of permanent magnets, and a plurality of first spacers and a plurality of second spacers made of a non-magnetic material. and a rotor provided rotatably with respect to the stator about a central axis, each of the embedding holes having a loading area loaded with the permanent magnet, and a loading area loaded with the permanent magnet; an outer gap region extending from the loading region to the outer peripheral side of the rotor core in a direction orthogonal to the magnetization direction of the rotor core and having a first concave surface recessed in the magnetization direction; and the loading region in a direction orthogonal to the magnetization direction an inner peripheral side gap region having a second concave surface extending in the inner peripheral side of the rotor core from the rotor core and recessed in the magnetization direction, and the rotor core protrudes into each of the outer peripheral side gap regions. Each of the permanent magnets has a first engaging projection forming the first concave surface and a second engaging convex portion protruding into each of the inner peripheral side gap regions and forming the second concave surface. has an outer peripheral side end face that faces the first concave surface and is not in contact with the rotor core, and an inner peripheral side end face that faces the second concave surface and is not in contact with the rotor core, The first spacer is loaded between the outer peripheral side end face and the first concave surface, and holds the outer peripheral side end face and the first concave face in a separated state, and the second spacer is the inner peripheral side end face. and the second concave surface, holds the inner peripheral side end surface and the second concave surface in a separated state, and protrudes into the respective embedding holes. The two locking protrusions lock the first spacer, the permanent magnet, and the second spacer positioned between them, and each of the permanent magnets engages the first magnetic pole surface and the second magnetic pole surface. The outer gap area further comprises a first inner surface including the first concave surface and continuous from an inner inner surface facing the first magnetic pole surface in the loading area, and the and a second inner surface continuous from the outer inner surface facing the second magnetic pole surface, and the first spacer is in contact with both the first inner surface and the second inner surface.

FIG. 1 is a cross-sectional view showing a rotating electric machine according to one embodiment. FIG. 2 is a cross-sectional view of the stator and rotor of FIG. 1 along line II-II. FIG. 3 is a cross-sectional view showing an enlarged part of the rotor of the comparative example of the rotating electric machine. FIG. 4 is a further enlarged cross-sectional view showing a part of the rotor shown in FIG. 3, together with magnetic flux lines. FIG. 5 is a cross-sectional view showing an enlarged part of the rotor of Example 1 of the rotating electric machine. FIG. 6 is a cross-sectional view showing an enlarged part of the rotor of Example 2 of the rotating electric machine.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the disclosure is merely an example, and those skilled in the art will naturally include within the scope of the present invention any appropriate modifications that can be easily conceived while maintaining the gist of the invention. In addition, in order to make the description clearer, the drawings may schematically show the width, thickness, shape, etc. of each part compared to the actual embodiment, but this is only an example, and the interpretation of the present invention is not intended. It is not limited. In addition, in this specification and each figure, the same reference numerals may be given to the same elements as those described above with respect to the existing figures, and detailed description thereof may be omitted as appropriate.

In this embodiment, the rotary electric machine 1 will be described. The rotary electric machine 1 is an embedded magnet synchronous motor. The rotating electrical machine 1 is suitably applied to a drive motor or generator in, for example, a hybrid vehicle (HEV) or an electric vehicle (EV).
FIG. 1 is a cross-sectional view showing a rotating electric machine 1 according to this embodiment. FIG. 2 is a cross-sectional view of stator 12 and rotor 14 of FIG. 1 taken along line II--II.

As shown in FIGS. 1 and 2, a rotating electrical machine 1 of the present embodiment is configured as a permanent magnet type rotating electrical machine. The rotating electrical machine 1 includes a stator 12 , a rotor 14 , a housing 6 that houses a portion of the rotor 14 and the stator 12 , and a cover 7 fixed to the housing 6 . The rotor 14 is positioned inside the stator 12 and is rotatably supported around the central axis C and coaxially supported with the stator 12 .

The stator 12 includes a cylindrical stator core 16 , coils (stator coils) 18 attached to the stator core 16 , and insulating paper 25 . The stator core 16 is configured as a laminate in which a large number of circular magnetic steel plates 16a made of a magnetic material, such as silicon steel, are concentrically laminated. The stator core 16 has a central axis C. As shown in FIG. In addition, in the direction parallel to the central axis C, the stator core 16 has a first end face 16b positioned at one end and a second end face 16c positioned at the other end opposite to the first end face 16b. ing. A plurality of slots 20 are formed in the inner peripheral surface 16 d of the stator core 16 . The plurality of slots 20 are arranged at regular intervals in the circumferential direction of the stator core 16 . Each slot 20 opens in the inner peripheral surface 16d of the stator core 16 and extends radially (radially of the stator core 16) from the inner peripheral surface. In addition, each slot 20 extends over the entire length of the stator core 16 in the direction parallel to the central axis C and opens to the first end surface 16b and the second end surface 16c.

An insulating paper 25 is wound around the coil 18 , and the coil 18 is embedded in the slot 20 together with the insulating paper 25 . The insulating paper 25 electrically insulates the coil 18 from the outside and physically protects the coil 18 . By forming the plurality of slots 20 , the inner peripheral portion of the stator core 16 constitutes a large number of teeth 21 facing the rotor 14 . In addition, each tooth 21 extends in a direction parallel to the center axis C. As shown in FIG.

The coil 18 has coil ends 18a and 18b. The coil ends 18 a and 18 b protrude from both sides of the stator core 16 in a direction parallel to the central axis C and are exposed outside the stator core 16 . Here, the coil end 18a faces the first end face 16b, and the coil end 18b faces the second end face 16c. The ends of the coil ends 18 a and 18 b on the stator core 16 side are covered with insulating paper 25 .
The housing 6 has a substantially cylindrical inner peripheral surface 6a. A stator 12 is fixed to the housing 6 .

The rotor 14 is positioned closer to the center axis C than the stator 12 . The rotor 14 is arranged with a slight gap (air gap) between itself and the stator 12 , and is rotatably supported inside the stator 12 coaxially with the stator 12 . The rotor 14 includes a rotating shaft 22, a cylindrical rotor core 24, a plurality of permanent magnets 26 embedded in the rotor core 24, a cylindrical first end plate 2, and a cylindrical second end plate. A plate 5, a washer 3 and a nut 4 are provided.

The rotating shaft 22 extends in a direction parallel to the central axis C and is provided coaxially with the rotor core 24 . Bearings 8 and 9 are attached to the rotating shaft 22 . Bearings 8 and 9 are fixed by housing 6 and cover 7 . The rotating shaft 22 is rotatably supported by the housing 6 and the cover 7 via bearings 8 and 9 . The illustrated example simply shows an example of a bearing structure that supports the rotating shaft 22, and a detailed description of the structure is omitted.

A rotor core 24 , a first end plate 2 and a second end plate 5 are fixed to the rotating shaft 22 . In this embodiment, the rotary shaft 22 has a protruding portion 22a and a male thread 22b. The protruding portion 22a and the male thread 22b are positioned on the outer peripheral surface side of the rotating shaft 22 and are positioned in a direction parallel to the central axis C with an interval therebetween. The projecting portion 22a is a collar portion and has an annular shape.

The first end plate 2 , rotor core 24 and second end plate 5 are inserted into the rotating shaft 22 . In the direction parallel to the central axis C, the first end plate 2, the rotor core 24, and the second end plate 5 are positioned between the protrusion 22a and the male screw 22b. The rotor core 24 is sandwiched between the first end plate 2 and the second end plate 5 in a direction parallel to the center axis C. As shown in FIG. The nut 4 has a female thread 4a corresponding to the male thread 22b. The female thread 4a is screwed onto the male thread 22b, and the nut 4 presses the first end plate 2, the rotor core 24, and the second end plate 5 against the projecting portion 22a via the washer 3. The nut 4 functions as a set screw. Therefore, the relative positions of the first end plate 2, the rotor core 24, and the second end plate 5 with respect to the rotating shaft 22 are fixed.

In this embodiment, the rotating shaft 22 has a cylindrical shape and is hollow inside. By using the cylindrical rotating shaft 22, the weight of the rotor 14 can be reduced. However, unlike this embodiment, the rotating shaft 22 may be a solid shaft.
The rotor core 24 has a magnetic material, for example, a large number of annular electromagnetic steel plates 24a. The rotor core 24 is configured as a laminate in which a plurality of concentric electromagnetic steel plates 24a are laminated in a direction parallel to the central axis line C. As shown in FIG. The rotor core 24 has a plurality of embedded holes 34 and a plurality of air holes (cavities) 30 . For example, the embedded hole 34 and the gap hole 30 are formed by laminating a plurality of pressed electromagnetic steel sheets 24a.

Each embedding hole 34 extends in a direction parallel to the center axis C and penetrates the rotor core 24 . Each permanent magnet 26 extends in a direction parallel to the central axis C and is inserted into a corresponding embedded hole 34 . The plurality of permanent magnets 26 (the plurality of embedding holes 34) are arranged in the circumferential direction around the central axis C. As shown in FIG. For example, the rotor 14 shown in FIG. 2 has 8 poles and uses 16 permanent magnets 26 . These 16 permanent magnets 26 have the same shape and size.

The rotor core 24 has a d-axis AX1 extending in a direction orthogonal to the central axis C or in a radial direction of the rotor core 24, and a q-axis AX2 electrically orthogonal to the d-axis AX1. The d-axis AX1 and the q-axis AX2 are provided alternately in the circumferential direction of the rotor core 24 and at predetermined phases. One magnetic pole of the rotor core 24 refers to the area between the q-axis AX2 (circumferential angle area of 1/8 circumference). Therefore, the rotor core 24 is configured to have eight poles (magnetic poles). The center of one magnetic pole in the circumferential direction is the d-axis AX1.

The air gap hole 30 extends in a direction parallel to the center axis C and penetrates the rotor core 24 . Each air gap hole 30 is located on the q-axis AX2 and substantially in the center in the radial direction of the rotor core 24, and is provided between two embedding holes 34 of adjacent magnetic poles. The air gap hole 30 has a polygonal, for example, triangular cross-sectional shape. The cross section of the air gap hole 30 has one side orthogonal to the q-axis AX2 and two sides facing the embedding hole 34 with a gap therebetween. The gap hole 30 functions as a flux barrier that makes it difficult for magnetic flux to pass through, and regulates the flow of interlinkage magnetic flux of the stator 12 and the flow of magnetic flux of the permanent magnet 26 . Further, by forming the air gap holes 30, the weight of the rotor core 24 can be reduced.

The rotor core 24 has a first end face 24s1 and a second end face 24s2 opposite to the first end face 24s1 in the direction parallel to the center axis C. As shown in FIG. Each permanent magnet 26 is embedded over substantially the entire length of the rotor core 24 . The first end plate 2 faces the first end face 24s1 and the plurality of permanent magnets 26 and covers the first end face 24s1 and the plurality of permanent magnets 26 .

The first end plate 2 is in contact with the first end surface 24s1. The first end plate 2 may further contact end faces of the plurality of permanent magnets 26 that are exposed on the first end face 24s1 side. The second end plate 5 faces the second end face 24 s 2 and the plurality of permanent magnets 26 and covers the second end face 24 s 2 and the plurality of permanent magnets 26 . The second end plate 5 is in contact with the second end face 24s2. The second end plate 5 may further contact end faces of the plurality of permanent magnets 26 that are exposed on the second end face 24s2 side.
In the rotating electric machine 1 , when a current is passed through the coil 18 , magnetic flux is generated around the coil 18 . The rotor 14 (rotating shaft 22) rotates about the central axis C by the magnetic flux acting on the permanent magnets 26 of the rotor 14. As shown in FIG.

Next, the rotor 14 of Example 1, the rotor 14 of Example 2, and the rotor 14 of Comparative Example of the rotary electric machine 1 according to the present embodiment will be described.

(Comparative example)
First, the rotor 14 of the comparative example will be described. FIG. 3 is a cross-sectional view showing an enlarged part of the rotor 14 of the comparative example of the rotary electric machine 1. As shown in FIG.

As shown in FIG. 3, two permanent magnets 26 are embedded in the rotor core 24 for each magnetic pole. Embedding holes (magnet embedding holes) 34 having shapes corresponding to the shapes of the permanent magnets 26 are formed on both sides of each d-axis AX1 in the circumferential direction of the rotor core 24 . Two permanent magnets 26 are loaded and positioned within the embedding holes 34, respectively. The permanent magnets 26 may be fixed to the rotor core 24 by, for example, an adhesive or the like.

The embedding hole 34 has a substantially rectangular cross-sectional shape and is inclined with respect to the d-axis AX1. When viewed in a cross section perpendicular to the central axis C of the rotor core 24, the two embedding holes 34 are arranged side by side in a substantially V shape, for example. That is, the inner peripheral side ends of the two embedding holes 34 are adjacent to the d-axis AX1 and face each other with a slight gap therebetween. A narrow bridge portion (narrow magnetic path portion) 36 is formed between the inner peripheral side ends of the two embedding holes 34 in the rotor core 24 . The outer peripheral side ends of the two embedding holes 34 are separated from the d-axis AX1 along the circumferential direction of the rotor core 24 and are located near the outer peripheral surface of the rotor core 24 and near the q-axis AX2. As a result, the outer peripheral end of the embedding hole 34 faces the outer peripheral end of the embedding hole 34 of the adjacent magnetic pole across the q-axis AX2. In the rotor core 24 , a narrow bridge portion (narrow magnetic path portion) 38 is formed between the outer peripheral side end of each embedding hole 34 and the outer peripheral surface of the rotor core 24 . In this way, the two embedding holes 34 are arranged such that the distance from the d-axis AX1 gradually widens from the inner peripheral end to the outer peripheral end.

The cross-sectional shape of the permanent magnet 26 perpendicular to the central axis C is, for example, a rectangular elongated flat plate shape. The permanent magnet 26 may be configured by combining a plurality of magnets divided in a direction parallel to the central axis C. In this case, the total length of the plurality of magnets is approximately the length of the rotor core 24 in the axial direction. formed to be equal. Each permanent magnet 26 is embedded over substantially the entire length of the rotor core 24 . The magnetization direction of the permanent magnet 26 is perpendicular to the first magnetic pole surface 26 a and the second magnetic pole surface 26 b of the permanent magnet 26 . One of the first magnetic pole face 26a and the second magnetic pole face 26b is the N pole face, and the other of the first magnetic pole face 26a and the second magnetic pole face 26b is the S pole face.

Each embedding hole 34 has a rectangular loading area 34a corresponding to the cross-sectional shape of the permanent magnet 26, and two gaps extending from both ends of the loading area 34a in the longitudinal direction. void region 34c).

The loading area 34a is defined between a flat rectangular inner peripheral side surface 35a and a flat rectangular outer peripheral side inner side surface 35b facing parallel to the inner peripheral side inner side surface 35a.

The outer peripheral side gap region 34c has a first inner side surface 46a, a second inner side surface 46b, and a third inner side surface 46c. The first inner side surface 46 a extends from one end of the inner peripheral side inner side surface 35 a of the loading area 34 a toward the outer peripheral edge 24 b of the rotor core 24 . The first inner surface 46 a has a first concave surface Sc<b>1 recessed in the magnetization direction of the permanent magnet 26 . The first concave surface Sc1 is formed by a locking convex portion 34d that protrudes into the outer peripheral side gap region 34c.

The second inner side surface 46 b extends from one end of the outer peripheral side inner side surface 35 b of the loading area 34 a (the end on the rotor core outer peripheral side) toward the outer peripheral edge 24 b of the rotor core 24 . The third inner side surface 46 c straddles the extended end of the first inner side surface 46 a and the extended end of the second inner side surface 46 b and extends along the outer peripheral edge 24 b of the rotor core 24 . Both ends of the third inner side surface 46c are connected to the first inner side surface 46a and the second inner side surface 46b via arcuate surfaces. A bridge portion 38 is defined between the third inner surface 46 c and the outer peripheral edge 24 b of the rotor core 24 .

The inner peripheral side gap region 34b has a fourth inner side surface 44a, a fifth inner side surface 44b, and a sixth inner side surface 44c. The fourth inner side surface 44a extends substantially parallel to the d-axis AX1 from the other end of the inner peripheral side inner side surface 35a of the loading area 34a toward the center axis C of the rotor core 24 (the inner peripheral edge 24c of the rotor core 24). out. The fourth inner surface 44 a has a second concave surface Sc<b>2 recessed in the magnetization direction of the permanent magnet 26 . The second concave surface Sc2 is formed by a locking convex portion 34d that protrudes into the inner peripheral side gap region 34b.

The fifth inner side surface 44b is continuous from the outer peripheral side inner side surface 35b. The fifth inner surface 44b does not protrude toward the outer peripheral edge 24b. The sixth inner side surface 44c straddles the extended end of the fourth inner side surface 44a and the extended end of the fifth inner side surface 44b, and extends substantially parallel to the d-axis AX1. Both ends of the sixth inner side surface 44c are connected to the fourth inner side surface 44a and the fifth inner side surface 44b via arcuate surfaces. In the inner peripheral side gap regions 34b of the two embedding holes 34, the sixth inner side surfaces 44c are arranged to face each other with the d-axis AX1 and the bridge portion 36 interposed therebetween.

The permanent magnet 26 is loaded in the loading area 34a of the embedding hole 34, the first magnetic pole surface 26a is in contact with the inner peripheral side surface 35a, and the second magnetic pole surface 26b is in contact with the outer peripheral side inner side surface 35b. One corner of the permanent magnet 26 is in contact with the first concave surface Sc1 (locking projection 34d), and the other corner of the permanent magnet 26 is in contact with the second concave surface Sc2 (locking projection 34d). Thereby, the permanent magnet 26 is positioned within the loading area 34a.

The two permanent magnets 26 located on both sides of each d-axis AX1, that is, the two permanent magnets 26 forming one magnetic pole, are arranged so that their magnetization directions are the same. The two permanent magnets 26 located on both sides of each q-axis AX2 are arranged so that their magnetization directions are opposite to each other. By arranging the plurality of permanent magnets 26 as described above, in the outer peripheral portion of the rotor core 24, the regions on each d-axis AX1 are formed around one magnetic pole, and the regions on each q-axis AX2 are formed between the magnetic poles. centered on the part. In this comparative example, the rotary electric machine 1 has 8 poles (4 pole pairs), 48 slots, in which the north and south poles of the permanent magnets 26 are alternately arranged for each adjacent magnetic pole, and is single-layer distributed winding. It constitutes a rotating electrical machine with a wound permanent magnet embedded.

FIG. 4 is a further enlarged cross-sectional view showing a part of the rotor 14 shown in FIG.
As shown in FIG. 4, in the comparative example, the diamagnetic field is likely to be applied to the outer peripheral side end and the inner peripheral side end of the permanent magnet 26 through the guide (locking protrusion 34d) of the permanent magnet 26. As shown in FIG. Here, the demagnetizing field is a magnetic field generated by the coil 18 in the direction opposite to the direction of the magnetic field of the permanent magnet 26 . If the apparent thickness of the outer and inner ends of the permanent magnet 26 looks thinner than the actual thickness, the magnetization will easily break. Therefore, demagnetization (reduction in magnetic force) is likely to occur at the outer peripheral side end portion and the inner peripheral side end portion of the permanent magnet 26 . For example, when a demagnetizing field is applied for the purpose of suppressing back electromotive force during high-speed rotation, the demagnetizing field concentrates on the locking protrusion 34d, and irreversible demagnetization tends to occur near the locking protrusion 34d.

Therefore, it is desirable that the apparent thickness of the outer and inner ends of the permanent magnet 26 be the same as the actual thickness. In other words, it is desirable to make it difficult for the demagnetizing field to enter the outer peripheral side end and the inner peripheral side end of the permanent magnet 26 . In other words, it is desirable to make it difficult for the magnetic field generated by the coil 18 to pass through the outer and inner ends of the permanent magnet 26 . As a result, demagnetization at the outer peripheral end and the inner peripheral end of the permanent magnet 26 can be suppressed. By suppressing the demagnetization of the permanent magnets 26, the rotating electric machine 1 with high energy efficiency can be obtained. Alternatively, it is possible to obtain the rotary electric machine 1 capable of increasing the output.

Since the centrifugal force of the permanent magnet 26 is applied to the locking protrusion 34d on the outer peripheral side, the size of the locking protrusion 34d on the outer peripheral side tends to be larger than the size of the locking protrusion 34d on the inner peripheral side. Therefore, it is desirable to be able to further suppress the demagnetization at the outer peripheral edge of the permanent magnet 26 . Therefore, in the first and second embodiments, techniques for suppressing demagnetization at the outer peripheral end and the inner peripheral end of the permanent magnet 26 are disclosed.

(Example 1)
Next, the rotor 14 of Example 1 will be described. FIG. 5 is a cross-sectional view showing an enlarged part of the rotor 14 of the first embodiment of the rotary electric machine 1. As shown in FIG.
As shown in FIG. 5, the embedding hole 34 has a loading area 34a, an inner peripheral gap area 34b, and an outer peripheral gap area 34c. A loading region 34a of the embedding hole 34 is configured in the same manner as in the comparative example (FIG. 3).

The outer gap region 34 c extends from the loading region 34 a toward the outer circumference of the rotor core 24 in a direction orthogonal to the magnetization direction of the permanent magnets 26 . The outer peripheral side gap region 34c has a first inner side surface 46a, a second inner side surface 46b, and a third inner side surface 46c.

The first inner side surface 46a is continuous from the inner peripheral inner side surface 35a of the loading area 34a facing the first magnetic pole surface 26a. The first inner surface 46 a has a first concave surface Sc<b>1 recessed in the magnetization direction of the permanent magnet 26 . The first concave surface Sc1 is formed by a locking convex portion 34d that protrudes into the outer peripheral side gap region 34c.

The second inner side surface 46b is continuous from the outer peripheral side inner side surface 35b facing the second magnetic pole surface 26b in the loading area 34a. The third inner surface 46c is located between the first inner surface 46a and the second inner surface 46b and extends along the outer peripheral edge 24b. The third inner side surface 46c is connected to the first inner side surface 46a and the second inner side surface 46b via arc surfaces 46d and 46e. The arc surface 46d is located between the first inner surface 46a and the third inner surface 46c. The arc surface 46e is located between the second inner surface 46b and the third inner surface 46c.

The inner peripheral air gap region 34 b extends from the loading region 34 a to the inner peripheral side of the rotor core 24 in a direction orthogonal to the magnetization direction of the permanent magnets 26 . The inner peripheral side gap region 34b does not protrude toward the outer peripheral edge 24b. The inner peripheral side gap region 34b has a fourth inner side surface 44a, a fifth inner side surface 44b, and a sixth inner side surface 44c.

The fourth inner side surface 44a continues from the inner peripheral side inner side surface 35a. The fourth inner surface 44 a has a second concave surface Sc<b>2 recessed in the magnetization direction of the permanent magnet 26 . The second concave surface Sc2 is formed by a locking convex portion 34d that protrudes into the inner peripheral side gap region 34b.

The fifth inner side surface 44b is continuous from the outer peripheral side inner side surface 35b. The sixth inner side surface 44c is located between the fourth inner side surface 44a and the fifth inner side surface 44b and extends substantially parallel to the d-axis AX1. The sixth inner side surface 44c is connected to the fourth inner side surface 44a and the fifth inner side surface 44b via arcuate surfaces 44d and 44e. The arc surface 44d is positioned between the fourth inner surface 44a and the sixth inner surface 44c. The arc surface 44e is positioned between the fifth inner surface 44b and the sixth inner surface 44c.

In addition to the first magnetic pole surface 26a and the second magnetic pole surface 26b, the permanent magnet 26 further has an outer peripheral end face 26c and an inner peripheral end face 26d opposite to the outer peripheral end face 26c. The outer peripheral side end surface 26 c faces the outer peripheral side gap region 34 c , faces the first concave surface Sc<b>1 (locking convex portion 34 d ), and is not in contact with the rotor core 24 . The inner peripheral side end surface 26 d faces the inner peripheral side gap region 34 b , faces the second concave surface Sc<b>2 (locking convex portion 34 d ), and does not contact the rotor core 24 . Therefore, demagnetization at each of the outer peripheral end portion and the outer peripheral end portion of the permanent magnet 26 can be suppressed. The permanent magnets 26 may be fixed to the rotor core 24 by, for example, an adhesive or the like.

The first spacer 61 and the second spacer 62 are made of non-magnetic material. In Example 1, the first spacer 61 and the second spacer 62 are made of nonmagnetic metal such as aluminum, nonmagnetic steel, or stainless steel. Moreover, if the first spacer 61 and the second spacer 62 have sufficient rigidity and can prevent the positional displacement of the permanent magnet 26, the first spacer 61 and the second spacer 62 can be made of a material other than metal such as resin. may be formed.

The first spacer 61 is loaded between the outer peripheral end surface 26c and the first concave surface Sc1. The first spacer 61 is in contact with the outer peripheral end surface 26c and the first concave surface Sc1. The first spacer 61 holds a gap between the outer peripheral end surface 26c and the first concave surface Sc1. The first spacer 61 may be fixed to the permanent magnet 26 and the rotor core 24 by, for example, an adhesive or the like.

The second spacer 62 is loaded between the inner peripheral side end surface 26d and the second concave surface Sc2. The second spacer 62 is in contact with the inner peripheral end surface 26d and the second concave surface Sc2. The second spacer 62 holds a gap between the inner peripheral side end surface 26d and the second concave surface Sc2. The second spacer 62 may be fixed to the permanent magnet 26 and the rotor core 24 by, for example, an adhesive or the like.

In the first embodiment, the first spacer 61 is positioned only between the outer peripheral end surface 26c and the first concave surface Sc1. The second spacer 62 is positioned only between the inner peripheral side end surface 26d and the second concave surface Sc2. Since the size of the first spacer 61 and the second spacer 62 can be reduced, the manufacturing cost of the first spacer 61 and the second spacer 62 can be reduced.

The first spacer 61 and the second spacer 62 do not have to be provided over substantially the entire length of the embedding hole 34 , but it is desirable that they are provided over substantially the entire length of the embedding hole 34 . This makes it possible to reduce the recesses of the first concave surface Sc1 (the projections of the locking projections 34d) and the recesses of the second concave surface Sc2 (the projections of the locking projections 34d).

Since the first spacers 61 are installed in each of the outer peripheral gap regions 34c and the second spacers 62 are installed in each of the inner peripheral gap regions 34b, the rotor 14 includes a plurality of first spacers 61 and A plurality of second spacers 62 are provided.

In the first embodiment, the first inner side surface 46a rather than the second inner side surface 46b has the first concave surface Sc1. As a result, the centrifugal force of the permanent magnets 26 applied to the rotor core 24 can be dispersed to the outer peripheral side inner surface 35b and the first concave surface Sc1 (locking convex portion 34d), which are positioned apart from each other. Breakage of the iron core 24 can be suppressed.

Next, the relationship between the thickness and distance of the rotor 14 will be described. Let T be the thickness of the permanent magnet 26 in the magnetization direction. L1 is the shortest distance from the first corner 26e between the second magnetic pole surface 26b and the outer peripheral end surface 26c to the first concave surface Sc1. Let L2 be the shortest distance from the second corner 26f between the second magnetic pole surface 26b and the inner peripheral side end surface 26d to the second concave surface Sc2.

Then, it is desirable that each of the distance L1 and the distance L2 is 0.5 times or more the thickness T (0.5T≦L1 and 0.5T≦L2). Since the position of the permanent magnet 26 can be separated from the first concave surface Sc1 and the second concave surface Sc2, demagnetization at the outer peripheral side end and the inner peripheral side end of the permanent magnet 26 can be suppressed.

Moreover, each of the distance L1 and the distance L2 is preferably 0.9 times or less the thickness T (L1≦0.9T and L2≦0.9T). By keeping the positions of the permanent magnets 26 from the first concave surface Sc1 and the second concave surface Sc2 more than necessary, reduction in the size of the permanent magnets 26 and increase in the size of the rotor core 24 can be suppressed.
From the above, it is preferable that 0.5T≦L1≦0.9T and 0.5T≦L2≦0.9T.

Next, the relationship between the first concave surface Sc1 (locking convex portion 34d), the second concave surface Sc2 (locking convex portion 34d), the first spacer 61, and the second spacer 62 will be described. In Example 1, the first concave surface Sc1 is recessed more in the magnetization direction of the permanent magnet 26 than the second concave surface Sc2. Here, in the above magnetization direction, when the extended surface S1 of the inner peripheral side surface 35a is used as a reference, the depth of the first concave surface Sc1 is D1, and the depth of the second concave surface Sc2 is D2. Let W1 be the first width of the first spacer 61 and W2 be the second width of the second spacer 62 in the direction perpendicular to the magnetization direction.

Then, in the magnetization direction, the first concave surface Sc1 is deeper than the second concave surface Sc2 (D2<D1). When D2<D1 as described above, the first width W1 is preferably equal to or greater than the second width W2 (W2≦W1). The second width W2 can be made close to 0 (zero), for example. Therefore, reduction in the size of the permanent magnets 26 and increase in the size of the rotor core 24 can be suppressed.

(Example 2)
Next, the rotor 14 of Example 2 is demonstrated. FIG. 6 is a cross-sectional view showing an enlarged part of the rotor 14 of Example 2 of the rotary electric machine 1. As shown in FIG. The second embodiment differs from the first embodiment in terms of the shapes of the first spacer 61 and the second spacer 62 .

As shown in FIG. 6, in the second embodiment, the first spacers 61 are positioned other than between the outer peripheral end surface 26c and the first concave surface Sc1. The second spacer 62 is also located between the inner peripheral side end surface 26d and the second concave surface Sc2. The first spacer 61 contacts both the first inner side surface 46a and the second inner side surface 46b. The second spacer 62 contacts both the fourth inner surface 44a and the fifth inner surface 44b.

The first spacer 61 is less likely to come off from between the outer peripheral end surface 26c and the first concave surface Sc1, and the second spacer 62 is less likely to come off from between the inner peripheral end surface 26d and the second concave surface Sc2. Therefore, positional displacement of the permanent magnets 26 can be suppressed.

Also in the second embodiment, 0.5T≦L1≦0.9T, and preferably 0.5T≦L2≦0.9T. Moreover, since D2<D1, it is preferable that W2≦W1.

According to the embodiment configured as described above, the rotating electrical machine 1 with high energy efficiency can be obtained. Alternatively, it is possible to obtain the rotary electric machine 1 capable of increasing the output. The energy efficiency of the rotary electric machine 1 can be improved and the output can be increased without adding a heavy rare earth element to the permanent magnet 26 to improve the coercive force or increasing the thickness of the permanent magnet 26.例文帳に追加Therefore, an increase in the manufacturing cost of the permanent magnets 26 can be suppressed.

While embodiments of the invention have been described, the above embodiments are provided by way of example and are not intended to limit the scope of the invention. The novel embodiments described above can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. The above-described embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

For example, the second inner surface 46b may have the first concave surface Sc1. In this case, the distance L1 is the shortest distance from the corner between the first magnetic pole surface 26a and the outer peripheral end surface 26c to the first concave surface Sc1. Similarly, the fifth inner surface 44b may have the second concave surface Sc2. In that case, the distance L2 is the shortest distance from the corner between the first magnetic pole surface 26a and the inner peripheral side end surface 26d to the second concave surface Sc2.

The number of magnetic poles, dimensions, shape, etc. of the rotor are not limited to the above-described embodiments, and can be changed in various ways according to the design. The cross-sectional shapes of the inner peripheral side gap region, the outer peripheral side gap region, and the gap holes are not limited to the shapes of the embodiments, and various shapes can be selected. In each magnetic pole, the number of permanent magnets is not limited to one pair, and may be three or more.

DESCRIPTION OF SYMBOLS 1... Rotary electrical machine, 12... Stator, 16... Stator core, 18... Coil, 14... Rotor,
24... Rotor core, 24b... Peripheral edge, 34... Embedding hole, 34a... Loading area,
35a... Inner surface on the inner peripheral side, 35b... Inner surface on the outer peripheral side, 34d... Locking projection,
34c... outer peripheral side gap area, 46a... first inner surface, 46b... second inner surface,
46c... Third inner surface, Sc1... First concave surface, 34b... Inner circumference side void area,
44a... 4th inner surface, 44b... 5th inner surface, 44c... 6th inner surface, Sc2... 2nd concave surface,
38...Bridge portion 26...Permanent magnet 26a...First magnetic pole face 26b...Second magnetic pole face
26c... outer peripheral side end face, 26d... inner peripheral side end face, 26e... first corner, 26f... second corner,
61... First spacer, 62... Second spacer, L1, L2... Distance, T... Thickness,
W1, W2...width, C...center axis.

Claims (5)

a stator having a stator core and coils;
a rotor core in which a plurality of embedding holes are formed; a plurality of permanent magnets; and a plurality of first spacers and a plurality of second spacers made of a non-magnetic material. a rotor provided rotatably with respect to the stator,
Each of the embedding holes includes a loading area in which the permanent magnet is loaded, and a second magnet extending from the loading area to the outer peripheral side of the rotor core in a direction perpendicular to the magnetization direction of the permanent magnet and recessed in the magnetization direction. an outer gap region having one concave surface, and an inner gap region having a second concave surface extending from the loading region toward the inner circumference of the rotor core in a direction perpendicular to the magnetization direction and recessed in the magnetization direction. , has
The rotor core includes first locking projections projecting into each of the outer peripheral side gap regions and forming the first concave surface, and second locking projections projecting into each of the inner peripheral side gap regions and forming the second concave surface. 2 locking projections,
Each of the permanent magnets has an outer peripheral end face facing the first concave surface and not in contact with the rotor core, an inner peripheral end face facing the second concave surface and not in contact with the rotor core, has
The first spacer is loaded between the outer peripheral side end surface and the first concave surface, and holds the outer peripheral side end surface and the first concave surface in a separated state,
The second spacer is loaded between the inner peripheral side end surface and the second concave surface, and holds the inner peripheral side end surface and the second concave surface in a separated state,
The first locking projection and the second locking projection projecting into the respective embedding holes lock the first spacer, the permanent magnet, and the second spacer positioned therebetween. death,
each said permanent magnet further comprising a first pole face and a second pole face;
The outer gap area includes a first inner surface including the first concave surface and continuous from an inner inner surface facing the first magnetic pole surface in the loading area, and the second magnetic pole surface in the loading area. and a second inner surface continuous from the inner surface on the outer peripheral side facing the
the first spacer contacts both the first inner surface and the second inner surface;
rotating electric machine. Assuming that the thickness of the permanent magnet in the magnetization direction is T, and the shortest distance from the first corner between the second magnetic pole face and the outer peripheral end face to the first concave face is L1,
0.5T≦L1≦0.9T,
The rotary electric machine according to claim 1. The inner peripheral gap region has a fourth inner surface that includes the second concave surface and is continuous from the inner peripheral inner surface facing the first magnetic pole surface in the loading region,
Assuming that the thickness of the permanent magnet in the magnetization direction is T, and the shortest distance from the second corner between the second magnetic pole face and the inner peripheral side end face to the second concave face is L2,
0.5T≤L2≤0.9T,
The rotary electric machine according to claim 1. the first concave surface is recessed more in the magnetization direction than the second concave surface;
Assuming that the width of the first spacer is W1 and the width of the second spacer is W2 in the direction perpendicular to the magnetization direction,
W2≤W1,
The rotary electric machine according to claim 1. a stator having a stator core and coils;
a rotor core in which a plurality of embedding holes are formed; a plurality of permanent magnets; and a plurality of first spacers and a plurality of second spacers made of a non-magnetic material. a rotor provided rotatably with respect to the stator,
Each of the embedding holes includes a loading area in which the permanent magnet is loaded, and a second magnet extending from the loading area to the outer peripheral side of the rotor core in a direction perpendicular to the magnetization direction of the permanent magnet and recessed in the magnetization direction. an outer gap region having one concave surface, and an inner gap region having a second concave surface extending from the loading region toward the inner circumference of the rotor core in a direction perpendicular to the magnetization direction and recessed in the magnetization direction. , has
The rotor core includes first locking projections projecting into each of the outer peripheral side gap regions and forming the first concave surface, and second locking projections projecting into each of the inner peripheral side gap regions and forming the second concave surface. 2 locking projections,
Each of the permanent magnets has an outer peripheral end face facing the first concave surface and not in contact with the rotor core, an inner peripheral end face facing the second concave surface and not in contact with the rotor core, has
The first spacer is loaded between the outer peripheral side end surface and the first concave surface, and holds the outer peripheral side end surface and the first concave surface in a separated state,
The second spacer is loaded between the inner peripheral side end surface and the second concave surface, and holds the inner peripheral side end surface and the second concave surface in a separated state,
The first locking projection and the second locking projection projecting into the respective embedding holes lock the first spacer, the permanent magnet, and the second spacer positioned therebetween. death,
each said permanent magnet further comprising a first pole face and a second pole face;
The inner peripheral gap region includes a fourth inner surface including the second concave surface and continuous from the inner peripheral inner surface facing the first magnetic pole surface in the loading region, and the second magnetic pole in the loading region. a fifth inner surface continuous from the inner surface on the outer peripheral side facing the surface,
the second spacer contacts both the fourth inner surface and the fifth inner surface ;
rotating electric machine.

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