JP7548056B2 - Rotor and IPM motor - Google Patents

Description

The present invention relates to a rotor and an IPM motor.

A rotor is known in which multiple steel plates stacked in the thickness direction are crimped in the stacking direction around the magnet insertion hole, so that the inner surface of the magnet insertion hole is pressed against the magnet inserted in the magnet insertion hole. For example, Patent Document 1 discloses such a rotor in which a through hole formed in a rotor core and housing a magnet has a recess formed on the inner surface that is recessed toward the side opposite the magnet, and the open end of the recess that opens toward the magnet side is pressed against the magnet.

In Patent Document 1, the recess has a shape recessed inward from the radial inner surface of the through hole. In other words, the radial outer end of the recess is configured as an open tip that opens toward the magnet in the radial direction, and the opposite radial inner end is configured as a closed end. The recess is also formed in a substantially rectangular shape with a pair of circumferential side walls that continue at a substantially right angle from the radial inner surface of the through hole.

The open ends of the recesses are plastically deformed radially outward by staking applied to the core sheets at both axial ends, and are pressed radially outward against the magnets. In other words, the magnets are fixed at both axial ends by the open ends of the recesses.

The staking is a so-called crimping process, and is performed at the radial center of the recess using a staking jig from both axial ends of the rotor core. This leaves a staking mark at the radial center of the recess.

JP 2013-34363 A

In the configuration described above, in which multiple steel plates stacked in the thickness direction are crimped in the stacking direction around the magnet insertion hole using a jig, when the steel plate located on the outermost surface in the stacking direction is pressed in the stacking direction by the jig, a part of the steel plate located between the crimped recess formed by the crimping and the magnet insertion hole is deformed axially outward.

In response to this, it is possible to reduce the force with which the jig presses the steel plate in the stacking direction so that the steel plate located between the crimping recess and the magnet insertion hole does not deform as described above. However, if the pressing force of the jig on the steel plate is reduced in this way, there is a possibility that a sufficient force cannot be obtained to crimp the multiple steel plates in the stacking direction.

The object of the present invention is to realize a rotor in which multiple steel plates stacked in the thickness direction are crimped in the stacking direction around the magnet insertion hole, in which the crimping recesses are formed in such a way that the portion of the steel plate located on the outermost surface in the stacking direction, located between the crimping recesses and the magnet insertion hole, is prevented from deforming axially outward of the stator core, while a force is obtained to crimp the multiple steel plates in the stacking direction.

A rotor according to one embodiment of the present invention is a rotor comprising a rotor magnet, a plurality of steel plates stacked in the thickness direction, and a rotor core having a magnet insertion hole penetrating the plurality of steel plates in the stacking direction and into which the rotor magnet is inserted. The rotor core has a crimping recess at an end in the stacking direction, which is located around the magnet insertion hole and is deeper than the thickness of one of the steel plates. The steel plate located on the outermost surface in the stacking direction among the plurality of stacked steel plates has an inner surface coating portion that covers at least a portion of the inner surface of the crimping recess.

An IPM motor according to one embodiment of the present invention includes a rotor having the above-described configuration and a stator having a stator coil and a stator core.

According to a rotor according to one embodiment of the present invention, in a rotor in which multiple steel plates stacked in the thickness direction are crimped in the stacking direction around the magnet insertion hole, a configuration can be realized in which the crimping recesses are formed in such a way that a force is obtained to crimp the multiple steel plates in the stacking direction while suppressing deformation of the portion of the steel plate located on the outermost surface in the stacking direction, which is located between the crimping recesses and the magnet insertion hole, in the axial outward direction of the stator core.

FIG. 1 is a schematic cross-sectional view including a central axis showing a general configuration of a motor according to an embodiment. FIG. 2 is a perspective view showing a schematic configuration of the stator core. FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a schematic diagram for explaining a method for forming the crimping recesses. FIG. 5 is a schematic diagram for explaining a method for forming the crimping recesses. FIG. 6 is a schematic diagram for explaining a method of forming crimping recesses in a rotor according to another embodiment. FIG. 7 is a diagram showing the configuration of a crimping recess of a rotor according to another embodiment.

Below, exemplary embodiments of the present invention will be described in detail with reference to the drawings. Note that the same or corresponding parts in the drawings will be given the same reference numerals and their description will not be repeated. Also, the dimensions of the components in each drawing do not faithfully represent the actual dimensions of the components or the dimensional ratios of each component.

In the following description of the motor 1, the direction parallel to the central axis P of the rotor 2 is referred to as the "axial direction," the direction perpendicular to the central axis P is referred to as the "radial direction," and the direction along the arc centered on the central axis P is referred to as the "circumferential direction." However, these definitions of directions are not intended to limit the orientation of the motor 1 when in use.

In addition, in the following description, the expressions "fixed," "connected," "joined," "attached," etc. (hereinafter, "fixed, etc.") include not only cases where members are directly fixed, etc. to each other, but also cases where members are fixed, etc. via other members. In other words, in the following description, the expression "fixed, etc." includes the meaning of direct and indirect fixation, etc. between members.

(Motor configuration)
1 shows a schematic configuration of a motor 1 including a rotor 2 according to an exemplary embodiment of the present invention. The motor 1 includes the rotor 2, a stator 3, and a housing 4. The rotor 2 rotates about a central axis P relative to the stator 3. In this embodiment, the motor 1 is a so-called inner rotor type motor in which the rotor 2 is positioned inside the cylindrical stator 3 so as to be rotatable about the central axis P.

The rotor 2 comprises a shaft 20, a rotor core 21, and a rotor magnet 22. The rotor 2 is located radially inward of the stator 3 and is rotatable relative to the stator 3.

The stator 3 is housed in the housing 4. In this embodiment, the stator 3 is cylindrical. The rotor 2 is located radially inward of the stator 3. In other words, the stator 3 is located radially opposite the rotor 2. The rotor 2 is located radially inward of the stator 3 and rotatable about the central axis P.

The stator 3 includes a stator core 31 and a stator coil 32. The stator coil 32 is wound around the stator core 31. A detailed description of the configuration of the stator 3 is omitted.

(Rotor Configuration)
2 is a perspective view showing a schematic configuration of rotor core 21. In this embodiment, rotor core 21 is cylindrical and extends along central axis P. Rotor core 21 has a through hole 21a extending along central axis P. Shaft 20 is fixed to rotor core 21 with shaft 20 passing through through hole 21a in the axial direction. This causes rotor core 21 to rotate together with shaft 20.

In this embodiment, the rotor core 21 has a plurality of magnet insertion holes 21b positioned at a predetermined interval in the circumferential direction. The plurality of magnet insertion holes 21b penetrate the rotor core 21 in the axial direction. Rotor magnets 22 are inserted into these magnet insertion holes 21b.

The rotor core 21 has multiple disk-shaped rotor core plates 23 formed into a predetermined shape and stacked in the thickness direction. The multiple rotor core plates 23 are electromagnetic steel plates. Each of the multiple rotor core plates 23 has an opening 23a that forms part of the magnet insertion hole 21b.

The rotor core plate 23 corresponds to the steel plate of the present invention.

The rotor core plates 23 stacked in the thickness direction are crimped in the stacking direction around the magnet insertion holes 21b. That is, the rotor core 21 has multiple crimp recesses 24 that are recessed in the axial direction around the magnet insertion holes 21b. In this embodiment, the crimp recesses 24 are located radially inward from the magnet insertion holes 21b in the rotor core 21. In the example shown in FIG. 2, two crimp recesses 24 are located radially inward from the magnet insertion holes 21b. However, there may be one crimp recess 24 located radially inward from the magnet insertion holes 21b, or three or more crimp recesses 24.

Figure 3 is a cross-sectional view taken along line III-III in Figure 2. Figure 3 shows the configuration of the crimping recess 24.

As shown in FIG. 3, the crimping recesses 24 are located at both ends of the rotor core 21 in the axial direction. As will be described in detail later, each crimping recess 24 is formed by pressing a jig M against the rotor core plate 23 located on the outermost surface in the stacking direction among the multiple rotor core plates 23 stacked in the thickness direction. The depth of the crimping recess 24 is deeper than the thickness of at least one rotor core plate 23. The crimping recess 24 may be formed only at one end in the axial direction of the rotor core 21. The rotor core plate 23 located on the outermost surface means the rotor core plate 23 located on the outermost axial direction of the rotor core 21 among the multiple rotor core plates 23 stacked in the thickness direction.

As shown in Figures 4 and 5, which will be described later, the jig M is a columnar member. The jig M has a tapered portion at its tip, the diameter of which decreases toward the tip. The tip of the jig M may be hemispherical.

The bottom 24a of the crimping recess 24 formed by pressing the tip of the jig M having the above-mentioned configuration against the rotor core plate 23 located on the outermost surface in the stacking direction among the multiple rotor core plates 23 stacked in the thickness direction has a shape that conforms to the tip of the jig M. That is, in this embodiment, the bottom 24a of the crimping recess 24 is circular when viewed in the axial direction of the rotor core 21.

By pressing the tip of the jig M against the rotor core plate 23 to form the crimping recess 24 in the rotor core 21, the intermediate portion 23c located between the crimping recess 24 and the magnet insertion hole 21b among the multiple rotor core plates 23 that make up the axial end of the rotor core 21 can be moved toward the inside of the magnet insertion hole 21b. In other words, with the crimping recess 24 as described above formed in the rotor core 21, a part of the inner surface of the magnet insertion hole 21b has moved toward the inside of the magnet insertion hole 21b.

As a result, part of the inner surface of the magnet insertion hole 21b is pressed against the rotor magnet 22 inserted into the magnet insertion hole 21b. Therefore, the rotor magnet 22 is held by its inner surface within the magnet insertion hole 21b.

A part of the rotor core plate 23 located on the outermost surface in the stacking direction among the multiple rotor core plates 23 stacked in the thickness direction is positioned on the side of the crimping recess 24. That is, the rotor core plate 23 located on the outermost surface in the stacking direction among the multiple stacked rotor core plates 23 has an inner surface covering portion 23b that covers at least a part of the inner surface of the crimping recess 24. The rotor core plate 23 located on the outermost surface is the rotor core plate 23 located at the axial end of the rotor core 21 among the multiple stacked rotor core plates 23.

As described above, in this embodiment, the rotor 2 includes a rotor magnet 22, a plurality of rotor core plates 23 stacked in the thickness direction, and a rotor core 21 having magnet insertion holes 21b that penetrate the plurality of rotor core plates 23 in the stacking direction and into which the rotor magnet 22 is inserted. The rotor core 21 has crimping recesses 24 at the ends in the stacking direction that are located around the magnet insertion holes 21b and are deeper than the thickness of one of the rotor core plates 23. The rotor core plate 23 located on the outermost surface in the stacking direction among the plurality of stacked rotor core plates 23 has an inner surface covering portion 23b that covers at least a portion of the inner surface of the crimping recess 24.

In this way, by forming a crimped recess 24 in the rotor core 21 using a jig M, the inner surface of which is at least partially covered by the inner covering portion 23b of the rotor core plate 23 located on the outermost surface in the stacking direction among the multiple rotor core plates 23 that make up the rotor core 21, the inner covering portion 23b of the rotor core plate 23 can be plastically deformed while the inner surface of the crimped recess 24 covered by the inner covering portion 23b of the rotor core plate 23 is moved toward the inside of the magnet insertion hole 21b.

This plastic deformation of the inner surface covering portion 23b makes it possible to hold the inner surface of the crimped recess 24 formed by the jig M. Therefore, the rotor magnet 22 inserted in the magnet insertion hole 21b can be kept pressed against the inner surface of the magnet insertion hole 21b. This makes it possible to more reliably hold the rotor magnet 22 in the magnet insertion hole 21b.

It is preferable that the inner surface covering portion 23b covers at least the portion of the inner surface of the crimping recess 24 that is close to the magnet insertion hole 21b. The portion of the inner surface of the crimping recess 24 that is close to the magnet insertion hole 21b means the portion of the inner surface of the crimping recess 24 that is the closest to the opening edge of the magnet insertion hole 21b when the crimping recess 24 is viewed in the stacking direction.

In this embodiment, the inner surface covering portion 23b covers the entire inner surface of the crimping recess 24. That is, in this embodiment, the inner surface covering portion 23b is cylindrical.

In this way, by covering the entire inner surface of the crimp recess 24 with the inner surface covering portion 23b of the rotor core plate 23 located on the outermost surface of the multiple rotor core plates 23 that make up the rotor core 21, the strength of the inner surface covering portion 23b can be improved.

Therefore, due to the plastic deformation of the inner surface covering portion 23b, the intermediate portion 23c located between the crimped recess 24 and the magnet insertion hole 21b in the rotor core 21 can be more reliably held in a state in which it has been moved inward into the magnet insertion hole 21b. Therefore, the state in which the inner surface of the magnet insertion hole 21b is pressed against the rotor magnet 22 inserted in the magnet insertion hole 21b can be more reliably held. Therefore, the rotor magnet 22 can be more reliably held in the magnet insertion hole 21b.

The inner surface covering portion 23b may be annular and cover the inner surface of the crimped recess 24. In other words, the inner surface covering portion 23b may be annular and cover at least a portion of the inner surface of the crimped recess 24 that is close to the magnet insertion hole 21b and extend in the circumferential direction of the crimped recess 24 when the rotor core 21 is viewed in the stacking direction.

In this way, by making the inner surface coating portion 23b of the rotor core plate 23 located on the outermost surface of the multiple rotor core plates 23 that make up the rotor core 21 into a circular ring shape, the strength of the inner surface coating portion 23b can be improved compared to when the inner surface coating portion is not circular.

Therefore, by plastically deforming the inner surface covering portion 23b using the jig M, the intermediate portion 23c located between the crimped recess 24 and the magnet insertion hole 21b in the rotor core 21 can be held in a state in which it has been moved inward into the magnet insertion hole 21b. This makes it possible to more reliably hold the state in which the inner surface of the magnet insertion hole 21b is pressed against the rotor magnet 22 inserted in the magnet insertion hole 21b.

The inner surface covering portion 23b may not be annular, but may be in a row extending in the depth direction of the crimping recess 24. Also, the rotor core plate 23 located on the outermost surface may have multiple inner surface covering portions 23b located on the inner circumferential surface of the crimping recess 24.

In this embodiment, at least a portion of the inner surface covering portion 23b overlaps with the rotor magnet 22 when the crimping recess 24 is viewed in a direction perpendicular to the stacking direction. That is, the inner surface covering portion 23b covers a portion of the side surface of the crimping recess 24 that is close to the magnet insertion hole 21b, and at least a portion of the inner surface covering portion 23b overlaps with the rotor magnet 22 when the crimping recess 24 is viewed in a direction perpendicular to the stacking direction.

In this way, by forming the crimped recess 24 covered by the inner surface covering portion 23b that overlaps with the rotor magnet 22 in the stacking direction when viewed in a direction perpendicular to the stacking direction in the rotor core 21 using the jig M, the inner surface of the crimped recess 24 covered by the inner surface covering portion 23b can be more reliably plastically deformed by moving the inner surface of the crimped recess 24 covered by the inner surface covering portion 23b toward the magnet insertion hole 21b.

By plastically deforming the inner surface covering portion 23b using such a jig M, the intermediate portion 23c of the rotor core 21 located between the crimped recess 24 and the magnet insertion hole 21b can be moved toward the rotor magnet 22 inserted into the magnet insertion hole 21b. This allows the inner surface of the magnet insertion hole 21b to be more reliably pressed against the rotor magnet 22 inserted into the magnet insertion hole 21b. This allows the rotor magnet 22 to be more reliably held within the magnet insertion hole 21b.

In this embodiment, the crimping recess 24 is located radially inward of the magnet insertion hole 21b in the rotor core 21. This allows the rotor magnet 22 to be held in the magnet insertion hole 21b while being positioned as radially outward as possible from the rotor core 21. This allows the rotor magnet 22 to be held in the magnet insertion hole 21b while improving the magnetic properties of the motor 1.

In this embodiment, the crimping recesses 24 are located at both ends of the rotor core 21 in the stacking direction. The rotor core plates 23 located on the outermost surfaces at both ends of the rotor core 21 in the stacking direction each have an inner surface coating portion 23b.

As a result, the rotor core 21 has crimping recesses 24 at both ends in the stacking direction. Therefore, at both ends in the stacking direction of the rotor core 21, the intermediate portions 23c located between the crimping recesses 24 and the magnet insertion holes 21b can be held in a state moved inward into the magnet insertion holes 21b. Therefore, the rotor magnets 22 inserted into the magnet insertion holes 21b of the rotor core 21 can be more securely held within the magnet insertion holes 21b.

As shown in FIG. 3, when the crimp recess 24 is viewed in the stacking direction, the shortest distance D between the crimp recess 24 and the magnet insertion hole 21b is smaller than the dimension W of the rotor magnet 22 in the radial direction of the rotor 2. The shortest distance D is the shortest distance between the opening edge of the crimp recess 24 that is closest to the opening edge of the magnet insertion hole 21b and the opening edge of the magnet insertion hole 21b that is closest to the opening edge of the crimp recess 24.

As a result, the crimping recess 24 is located close to the rotor magnet 22. Therefore, when forming the crimping recess 24 in the rotor core 21 using the jig M, the intermediate portion 23c of the rotor core 21 located between the crimping recess 24 and the magnet insertion hole 21b can be moved toward the rotor magnet 22 inserted in the magnet insertion hole 21b, and the inner surface of the magnet insertion hole 21b can be pressed against the rotor magnet 22 inserted in the magnet insertion hole 21b. Therefore, the rotor magnet 22 can be more securely held in the magnet insertion hole 21b.

(Method of forming crimping recess)
Next, a method for forming the crimping recess 24 having the above-mentioned configuration will be described.

Figures 4 and 5 show a schematic diagram of a jig M being pressed against multiple rotor core plates 23 stacked in the thickness direction in the stacking direction of the rotor core plates 23.

As shown in FIG. 4, each of the rotor core plates 23 stacked in the thickness direction has a crimping through hole 23d located near the opening 23a. A cavity V is formed by the crimping through holes 23d of the rotor core plates 23. That is, the rotor core before the crimping recesses 24 are formed has a cavity V in the portion where the crimping recesses 24 are to be formed. The cavity V is covered by the rotor core plates 23 located on the outermost surface of the rotor core plates 23 in the stacking direction.

When the multiple rotor core plates 23 are viewed in the stacking direction, the jig M is pressed against the rotor core plate 23 located on the outermost surface at a position overlapping the cavity portion V. As a result, as shown in FIG. 5, the tip of the jig M pushes the rotor core plate 23 located on the outermost surface into the cavity portion V. The diameter of the tip of the jig M is larger than the diameter of the cavity portion V. Therefore, the tip of the jig M pushes the rotor core plate 23 located on the outermost surface into the cavity portion V while expanding the cavity portion V in the radial direction.

As a result, as shown in FIG. 3, a crimped recess 24 is formed in the rotor core 21, the inner surface of which is covered by the inner surface covering portion 23b, which is part of the rotor core plate 23 located on the outermost surface. By forming the crimped recess 24 in the rotor core 21, the intermediate portion 23c of the rotor core 21 located between the crimped recess 24 and the magnet insertion hole 21b moves inward into the magnet insertion hole 21b. This causes the inner surface of the magnet insertion hole 21b to be pressed against the rotor magnet 22 inserted into the magnet insertion hole 21b. Thus, the rotor magnet 22 is held in the magnet insertion hole 21b.

Moreover, as described above, the inner surface of the crimped recess 24 is covered by the inner surface covering portion 23b, so that the inner surface of the crimped recess 24 can be held. As a result, the intermediate portion 23c of the rotor core 21 located between the crimped recess 24 and the magnet insertion hole 21b is held in a state of being moved inward into the magnet insertion hole 21b, so that the inner surface of the magnet insertion hole 21b can be held in a state of being pressed against the rotor magnet 22. Therefore, the rotor magnet 22 can be more reliably held within the magnet insertion hole 21b.

The formation of the crimping recesses 24 using the jig M as described above may be performed only on one axial end of the rotor core 21, or may be performed simultaneously on both axial ends of the rotor core 21, or may be performed at different times on both axial ends of the rotor core 21.

Other Embodiments
Although the embodiment of the present invention has been described above, the above-mentioned embodiment is merely an example for carrying out the present invention. Therefore, the present invention is not limited to the above-mentioned embodiment, and it is possible to carry out the above-mentioned embodiment by appropriately modifying it within the scope of the gist of the present invention.

In the above embodiment, the entire inner surface of the crimp recess 24 is covered by the inner surface covering portion 23b of the rotor core plate 23. However, only a portion of the inner surface of the crimp recess may be covered by the inner surface covering portion of the rotor core plate.

In the above embodiment, when forming the crimping recess 24 in the rotor core 21 using the jig M, the jig M is pressed into the cavity V covered by the rotor core plate 23 located on the outermost surface. However, the rotor core plate located on the outermost surface may have a through hole. Specifically, as shown in FIG. 6, the rotor core plate 23 located on the outermost surface among the multiple rotor core plates 23 stacked in the thickness direction may have a rotor core plate through hole 23e that connects to the cavity V. The tip of the jig M is pressed into the rotor core plate through hole 23e and then into the cavity V to form the crimping recess in the rotor core 21.

As a result, as shown in FIG. 7, a crimped recess 124 can be formed whose side is covered by the annular inner surface covering portion 123b of the rotor core plate 23 located on the outermost surface.

The crimping recess 124 may be formed at both axial ends of the rotor core 21, or may be formed at only one of the axial ends of the rotor core 21. Also, the side of the crimping recess 124 may be only partially covered by the inner surface coating.

Furthermore, at one of the axial ends of the rotor core 21, a crimped recess 124 whose side is covered by an annular inner surface covering portion 123b is formed as shown in FIG. 7, and at the other end, a crimped recess 24 whose entire surface is covered by an inner surface covering portion 23b is formed as shown in FIG. 3.

In the above embodiment, the inner surface covering portion 23b covering the inner surface of the crimp recess 24 is a part of the rotor core plate 23 located on the outermost surface of the multiple rotor core plates 23 stacked in the thickness direction. However, the inner surface covering portion covering the inner surface of the crimp recess may be a part of multiple rotor cores including the rotor core located on the outermost surface.

In the above embodiment, the inner surface covering portion 23b that covers the inner surface of the crimp recess 24 overlaps at least a portion of the inner surface covering portion 23b with the rotor magnet 22 when the crimp recess 24 is viewed in a direction perpendicular to the stacking direction. However, at least a portion of the inner surface covering portion does not have to overlap with the rotor magnet when the crimp recess is viewed in a direction perpendicular to the stacking direction.

In the above embodiment, the crimping recess 24 is located radially inward from the magnet insertion hole 21b in the rotor core 21. However, the crimping recess may be located radially outward from the magnet insertion hole in the rotor core.

In the above embodiment, the jig M has a tapered portion at the tip. However, the jig may have a protrusion at the tip that protrudes in the axial direction of the jig, or may have an inclined surface that is inclined relative to the axis of the jig.

In the above embodiment, the rotor core plate 23 is an electromagnetic steel plate. However, the rotor core plate may be a plate member other than an electromagnetic steel plate.

The present invention can be used for rotors that have crimping recesses formed by crimping multiple rotor core plates stacked in the thickness direction in the stacking direction.

Reference Signs List 1 Motor 2 Rotor 3 Stator 4 Housing 20 Shaft 21 Rotor core 21a Through hole 21b Magnet insertion hole 22 Rotor magnet 23 Rotor core plate 23a Opening 23b, 123b Inner surface covering portion 23c Middle portion 23d Crimping through hole 23e Rotor core plate through hole 24, 124 Crimping recess 24a Bottom portion 31 Stator core 32 Stator coil M Jig P Central axis V Hollow portion W Dimension D of rotor magnet in radial direction of rotor Shortest distance between crimping recess and magnet insertion hole

Claims (8)

A rotor magnet;
a rotor core including a plurality of steel plates laminated in a thickness direction and a magnet insertion hole penetrating the plurality of steel plates in the lamination direction and into which the rotor magnet is inserted;
A rotor comprising:
the rotor core has a crimping recess at an end in the lamination direction, the crimping recess being located around the magnet insertion hole and being deeper than a thickness of one of the steel plates;
At least a part of the stacked steel plates has a crimping through hole penetrating in the stacking direction,
Among the plurality of stacked steel plates, a steel plate located on the outermost surface in the stacking direction has an inner surface covering portion that covers at least a part of the inner surface of the crimping recess,
The inner surface covering portion is in contact with at least a portion of an inner circumferential surface of the crimping through hole . The rotor according to claim 1, wherein the inner surface covering portion covers at least a portion of the inner surface of the crimp recess that is close to the magnet insertion hole. 3. The rotor according to claim 2,
A rotor in which the inner surface covering portion covers a portion of the side of the crimping recess that is close to the magnet insertion hole, and when the crimping recess is viewed in a direction perpendicular to the stacking direction, at least a portion of the inner surface covering portion overlaps the rotor magnet. 4. The rotor according to claim 2 or 3,
A rotor, wherein the inner surface covering portion covers at least a portion of the inner surface of the crimping recess that is close to the magnet insertion hole and has an annular shape that extends in a circumferential direction of the crimping recess when the rotor core is viewed in the stacking direction. 3. The rotor according to claim 2,
The rotor, wherein the inner surface covering portion covers the entire inner surface of the crimping recess. A rotor according to any one of claims 1 to 5,
The crimping recess is located radially inward of the magnet insertion hole in the rotor core. A rotor according to any one of claims 1 to 6,
the crimping recesses are located at both ends of the rotor core in the lamination direction,
a rotor, wherein the steel plates located on the outermost surfaces at both ends of the rotor core in the lamination direction each have the inner surface covering portion. A rotor according to any one of claims 1 to 7;
a stator having a stator coil and a stator core;
An IPM motor comprising:

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