WO2024225275A1 - Rotor, rotating electrical machine, and drive device - Google Patents

Abstract

A rotor of one embodiment of the present invention is able to rotate about a central axis, and comprises: a rotor core; and an end plate that has a first plate surface facing the rotor core in the axial direction, and a second plate surface facing the inverse side from the first plate surface. The first plate surface comprises a contact surface that makes contact with the rotor core in the axial direction in a state where at least part of the end plate is elastically deformed in the axial direction. The contact surface comprises a first surface. In a state where the end plate is not elastically deformed, the first surface is, toward the radially outward side, located increasingly close to a first side of the axial direction where the rotor core is arranged with respect to the end plate, In the state where the end plate is not elastically deformed, a radially outward end of the first surface is the portion of the contact surface that is located closest to the first side. The end plate comprises a first recess provided to an outer surface of the end plate. At least part of the first recess overlaps the first surface in the axial direction.

Description

ROTOR, ROTATING ELECTRIC MACHINE, AND DRIVE DEVICE

The present invention relates to a rotor, a rotating electric machine, and a drive device.
This application claims priority based on Japanese Patent Application No. 2023-074685, filed on April 28, 2023, the contents of which are incorporated herein by reference.

　Conventionally, a rotor for a rotating electric machine is known that has an end plate that faces the rotor core in the axial direction (for example, Patent Document 1).

International Publication No. 2021/250921

In the case of end plates such as those described above, for example, in order to hold down the multiple plate members that make up the rotor core in the axial direction, the surface of the end plate facing the rotor core may be made into an inclined surface, and the end plate may be elastically deformed to deform the inclined surface into a surface perpendicular to the axial direction and brought into contact with the rotor core, thereby applying an axial force to the rotor core through the restoring force of the end plate. In this case, depending on the rigidity of the end plate, the end plate may not elastically deform appropriately, and part of the inclined surface may not contact the rotor core. As a result, there are cases in which the axial force applied from the end plate to the rotor core cannot be made sufficiently large.

In view of the above circumstances, one of the objects of the present invention is to provide a rotor, a rotating electric machine, and a drive unit that can improve the axial force applied to the rotor core from the end plates.

One aspect of the rotor of the present invention is a rotor that can rotate around a central axis, and includes a rotor core and end plates having a first plate surface that faces the rotor core in the axial direction and a second plate surface that faces the opposite side to the first plate surface. The first plate surface has a contact surface that contacts the rotor core in the axial direction when at least a portion of the end plate is elastically deformed in the axial direction. The contact surface has a first surface. When the end plate is not elastically deformed, the first surface is located on a first side in the axial direction where the rotor core is disposed relative to the end plate as it moves radially outward. When the end plate is not elastically deformed, the radially outer end of the first surface is the portion of the contact surface that is located furthest to the first side. The end plate has a first recess provided on the outer surface of the end plate. At least a portion of the first recess overlaps with the first surface in the axial direction.

One embodiment of the rotating electric machine of the present invention comprises the rotor described above and a stator that faces the rotor via a gap.

One embodiment of the drive device of the present invention includes the above-mentioned rotating electric machine and a gear mechanism connected to the rotating electric machine.

According to one aspect of the present invention, the axial force applied from the end plate to the rotor core can be improved in a rotor, a rotating electric machine, and a drive unit.

FIG. 1 is a diagram illustrating a drive device according to a first embodiment. FIG. 2 is a perspective view showing the rotor in the first embodiment. FIG. 3 is a cross-sectional view showing the rotor in the first embodiment. FIG. 4 is a cross-sectional view showing a part of the rotor in the first embodiment, illustrating the flow of oil inside the rotor. FIG. 5 is a view of a portion of the end plate in the first embodiment as viewed from the other axial side. FIG. 6 is a cross-sectional view showing a part of the rotor core and a part of the end plate in the first embodiment. FIG. 7 is an exploded perspective view showing a part of the rotor in the first embodiment. FIG. 8 is a perspective view showing an end plate in the first embodiment. FIG. 9 is a cross-sectional view showing a portion of the rotor in the first embodiment. FIG. 10 is a cross-sectional view showing a part of the rotor core and a part of the end plate before being fixed to the rotor core in the first embodiment. FIG. 11 is a perspective view showing a portion of the end plate. FIG. 12 is a cross-sectional view showing a portion of an end plate in the second embodiment. FIG. 13 is a view of a part of an end plate in the third embodiment as viewed from the other axial side. FIG. 14 is a cross-sectional view showing a part of a rotor according to the fourth embodiment.

In the drawings, the XYZ coordinate system is appropriately shown as a three-dimensional Cartesian coordinate system. In the XYZ coordinate system, the Z axis direction is the up-down direction. The side toward which the Z axis arrow points (+Z side) is the upper side, and the opposite side to the side toward which the Z axis arrow points (-Z side) is the lower side. The X axis direction is a direction perpendicular to the Z axis direction, and is the front-rear direction of the vehicle on which the drive device in the following embodiment is mounted. In the following embodiment, the side toward which the X axis arrow points (+X side) is the front side of the vehicle, and the opposite side to the side toward which the X axis arrow points (-X side) is the rear side of the vehicle. The Y axis direction is a direction perpendicular to both the X axis direction and the Z axis direction, and is the left-right direction of the vehicle, i.e., the vehicle width direction. In the following embodiment, the side toward which the Y axis arrow points (+Y side) is the left side of the vehicle, and the opposite side to the side toward which the Y axis arrow points (-Y side) is the right side of the vehicle.

Note that the positional relationship in the front-rear direction is not limited to that in the following embodiment, and the +X side may be the rear side of the vehicle, and the -X side may be the front side of the vehicle. In this case, the +Y side is the right side of the vehicle, and the -Y side is the left side of the vehicle. In this specification, "parallel direction" also includes substantially parallel directions, and "perpendicular direction" also includes substantially perpendicular directions.

The central axis J, as shown in the appropriate figures, is a virtual axis that extends in a direction that intersects with the up-down direction. More specifically, the central axis J extends in the Y-axis direction, which is perpendicular to the up-down direction, that is, in the left-right direction of the vehicle. In the following explanation, unless otherwise specified, the direction parallel to the central axis J will be simply referred to as the "axial direction", the radial direction centered on the central axis J will be simply referred to as the "radial direction", and the circumferential direction centered on the central axis J, that is, around the axis of the central axis J, will be simply referred to as the "circumferential direction". In the following explanation, the left side (+Y side) of the axial direction will be referred to as the "one axial side", and the right side (-Y side) of the axial direction will be referred to as the "other axial side". The up-down direction is, for example, the vertical direction, and the front-rear direction and left-right direction (axial direction) are, for example, horizontal directions perpendicular to the vertical direction.

The arrow θ shown in the appropriate figures indicates the circumferential direction. In the following explanation, the side of the circumferential direction that moves counterclockwise around the central axis J as viewed from one axial side (+Y side), i.e. the side to which the arrow θ points (+θ side), is referred to as the "one circumferential side," and the side of the circumferential direction that moves clockwise around the central axis J as viewed from one axial side, i.e. the opposite side to the side to which the arrow θ points (-θ side), is referred to as the "other circumferential side."

First Embodiment
A drive device 100 according to the present embodiment shown in Fig. 1 is a drive device mounted on a vehicle and rotates an axle 73 of the vehicle. The vehicle on which the drive device 100 is mounted is a vehicle that uses a motor as a power source, such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV). As shown in Fig. 1, the drive device 100 includes a rotating electric machine 60, a gear mechanism 70 connected to the rotating electric machine 60, and a housing 63 that houses the rotating electric machine 60 and the gear mechanism 70 therein. In this embodiment, the rotating electric machine 60 is a motor.

The housing 63 houses the rotating electric machine 60 and the gear mechanism 70. The housing 63 has a motor housing 63a that houses the rotating electric machine 60 therein, and a gear housing 63b that houses the gear mechanism 70 therein. The motor housing 63a is connected to the other axial side (-Y side) of the gear housing 63b. The motor housing 63a has a peripheral wall portion 63c, a partition wall portion 63d, and a lid portion 63e. The peripheral wall portion 63c and the partition wall portion 63d are, for example, part of the same single member. The lid portion 63e is, for example, separate from the peripheral wall portion 63c and the partition wall portion 63d.

The peripheral wall portion 63c is cylindrical and surrounds the central axis J, opening to the other axial side (-Y side). The partition portion 63d is connected to the end of the peripheral wall portion 63c on one axial side (+Y side). The partition portion 63d axially separates the interior of the motor housing 63a from the interior of the gear housing 63b. The partition portion 63d has a partition opening 63f that connects the interior of the motor housing 63a to the interior of the gear housing 63b. The partition portion 63d holds a bearing 64a. The lid portion 63e is fixed to the end of the peripheral wall portion 63c on the other axial side. The lid portion 63e closes the opening on the other axial side of the peripheral wall portion 63c. The lid portion 63e holds a bearing 64b.

The gear housing 63b contains oil O inside. The oil O is stored in a lower area inside the gear housing 63b. The oil O circulates inside a flow path 90, which will be described later. The oil O is used as a refrigerant that cools the rotating electric machine 60. The oil O is also used as a lubricant for the gear mechanism 70. As the oil O, it is preferable to use, for example, an oil equivalent to an automatic transmission lubricant (ATF: Automatic Transmission Fluid), which has a relatively low viscosity, in order to perform the functions of a refrigerant and a lubricant.

The gear mechanism 70 is connected to the rotating electric machine 60 and transmits the rotation of the rotor 10, which will be described later, to the axle 73 of the vehicle. In this embodiment, the gear mechanism 70 has a reduction gear 71 connected to the rotating electric machine 60, and a differential gear 72 connected to the reduction gear 71. The differential gear 72 has a ring gear 72a. The torque output from the rotating electric machine 60 is transmitted to the ring gear 72a via the reduction gear 71. The lower end of the ring gear 72a is immersed in oil O stored in the gear housing 63b. As the ring gear 72a rotates, the oil O is scooped up. The scooped up oil O is supplied, for example, to the reduction gear 71 and the differential gear 72 as lubricating oil.

The rotating electric machine 60 includes a rotor 10 that can rotate about a central axis J, and a stator 61 that faces the rotor 10 with a gap therebetween. In this embodiment, the stator 61 is located radially outside the rotor 10 and faces the rotor 10 in the radial direction. The stator 61 includes a stator core 61a and a coil assembly 61b attached to the stator core 61a. The coil assembly 61b includes a plurality of coils 61c attached to the stator core 61a. Although not shown, the coil assembly 61b may include a bundling member that bundles the coils 61c, or may include a jumper wire that connects the coils 61c together. The coil assembly 61b includes coil ends 61d, 61e that protrude axially beyond the stator core 61a.

The rotor 10 comprises a shaft 20 extending in the axial direction around a central axis J, and a rotor core 30 fixed to the outer peripheral surface of the shaft 20. As shown in FIG. 2, the rotor 10 comprises a plurality of magnets 40 held by the rotor core 30, end plates 80 arranged at both axial ends of the rotor core 30, and a plate 38.

The shaft 20 can rotate around the central axis J. As shown in FIG. 1, the shaft 20 is rotatably supported by bearings 64a and 64b. In this embodiment, the shaft 20 is a hollow shaft. The shaft 20 is cylindrical, and oil O can flow through it as a refrigerant. A reduction gear 71 is connected to the end of the shaft 20 on one axial side (+Y side). As shown in FIG. 2, the shaft 20 has a first fitting portion 21 that is recessed in the radial direction on the outer circumferential surface of the shaft 20. That is, the shaft 20 has the first fitting portion 21. The first fitting portion 21 is recessed radially inward from the outer circumferential surface of the shaft 20. The first fitting portion 21 extends in the axial direction. As shown in FIG. 3, in this embodiment, a pair of first fitting portions 21 are provided on either side of the central axis J in the radial direction. The inside of the first fitting portion 21 is substantially rectangular when viewed in the axial direction.

As shown in FIG. 1, the shaft 20 has a first shaft hole portion 22a extending in the axial direction. The interior of the first shaft hole portion 22a is formed by the interior of the shaft 20, which is a hollow shaft. In this embodiment, the first shaft hole portion 22a is a hole that penetrates the shaft 20 in the axial direction and is open on both axial sides. As shown in FIG. 3, in this embodiment, the first shaft hole portion 22a is a circular hole centered on the central axis J.

As shown in FIG. 4, the shaft 20 has a second shaft hole portion 22b that is connected to the first shaft hole portion 22a. The second shaft hole portion 22b is a hole that penetrates the wall portion of the shaft 20 in the radial direction from the inner peripheral surface of the shaft 20 to the outer peripheral surface of the shaft 20. The second shaft hole portion 22b opens to the inner peripheral surface and the outer peripheral surface of the shaft 20. In this embodiment, the second shaft hole portion 22b is a circular hole. In this embodiment, multiple second shaft holes 22b are provided at intervals from each other in the circumferential direction. The multiple second shaft holes 22b are arranged at equal intervals around one circumference in the circumferential direction.

As shown in FIG. 1, the shaft 20 has a shaft body 20a extending in the axial direction, and a flange 20b protruding radially outward from the outer circumferential surface of the shaft body 20a. The shaft body 20a is a cylindrical portion in which a first shaft hole 22a and a second shaft hole 22b are provided. The flange 20b is annular about the central axis J. The flange 20b is located on one axial side (+Y side) of an end plate 80b described later.

As shown in FIG. 3, the rotor core 30 is fixed to the outer peripheral surface of the shaft 20. The rotor core 30 is generally cylindrical and centered on the central axis J. The rotor core 30 has a hole 30h that penetrates the rotor core 30 in the axial direction. The central axis J passes through the inside of the hole 30h. In this embodiment, the hole 30h is a generally circular hole centered on the central axis J. The shaft 20 passes through the hole 30h in the axial direction. The inner peripheral surface of the hole 30h is fixed to the outer peripheral surface of the shaft 20. For example, the shaft 20 is press-fitted into the hole 30h.

The inner edge of the hole 30h is provided with a second fitting portion 32 that protrudes radially inward. In other words, the rotor core 30 has a second fitting portion 32. Although not shown, the second fitting portion 32 extends in the axial direction. A pair of second fitting portions 32 is provided for each core piece part 37 described below, with the central axis J sandwiched therebetween in the radial direction. The pair of second fitting portions 32 are respectively fitted into the pair of first fitting portions 21. This allows the shaft 20 and the rotor core 30 to hook onto each other in the circumferential direction, preventing the shaft 20 and the rotor core 30 from rotating relative to each other in the circumferential direction. The second fitting portion 32 is substantially rectangular when viewed in the axial direction.

The inner edge of the hole 30h is provided with a pair of first recesses 33a, 33b and a second recess 34 that are recessed radially outward. The pair of first recesses 33a, 33b are provided in two pairs, sandwiching the central axis J in the radial direction. Each pair of first recesses 33a, 33b is provided adjacent to both circumferential sides of each second fitting portion 32, sandwiching each second fitting portion 32 in the circumferential direction. A pair of second recesses 34 are provided, sandwiching the central axis J in the radial direction. When viewed in the axial direction, the pair of second recesses 34 are arranged on either side of the central axis J in a radial direction perpendicular to the radial direction in which the pair of second fitting portions 32 sandwich the central axis J. The pair of second recesses 34 extend in the circumferential direction. By providing the first recessed portions 33a, 33b and the second recessed portion 34, a part of the stress generated in the shaft 20 when the shaft 20 is press-fitted into the hole 30h can be released in the portion of the shaft 20 that faces the first recessed portions 33a, 33b and the second recessed portion 34 in the radial direction. Therefore, the shaft 20 can be easily press-fitted into the hole 30h.

The second fitting portion 32 provided on the inner edge of the hole 30h may be recessed radially outward, and the first fitting portion 21 provided on the outer circumferential surface of the shaft 20 may protrude radially outward. In this case, the first fitting portion 21 is fitted into the second fitting portion 32. Even in this case, it is possible to prevent the shaft 20 and the rotor core 30 from rotating relative to each other in the circumferential direction.

As shown in FIG. 2, the rotor core 30 has multiple core piece parts 37 arranged in the axial direction. The core piece parts 37 are magnetic. The core piece parts 37 are annular and surround the shaft 20. In this embodiment, the core piece parts 37 are annular and centered on the central axis J. The inner peripheral surface of the core piece parts 37 is fixed to the outer peripheral surface of the shaft 20 by press-fitting or the like. The core piece parts 37 and the shaft 20 are fixed so as to be immovable relative to each other in the axial, radial, and circumferential directions.

In this embodiment, the multiple core piece parts 37 include two first core piece parts 37A, two second core piece parts 37B, and two third core piece parts 37C. The two first core piece parts 37A sandwich the plate 38 in the axial direction. The two second core piece parts 37B sandwich the two first core piece parts 37A and the plate 38 in the axial direction. The two third core piece parts 37C sandwich the two second core piece parts 37B, the two first core piece parts 37A, and the plate 38 in the axial direction.

The first core piece part 37A, the second core piece part 37B, and the third core piece part 37C are arranged with a circumferential offset from each other. The second core piece part 37B is arranged with a circumferential offset from the axially adjacent first core piece part 37A toward the other circumferential side (-θ side). The third core piece part 37C is arranged with a circumferential offset from the axially adjacent second core piece part 37B. The twist direction of the skew in the first core piece part 37A, the second core piece part 37B, and the third core piece part 37C arranged side by side on one axial side (+Y side) of the plate 38 is opposite to the twist direction of the skew in the first core piece part 37A, the second core piece part 37B, and the third core piece part 37C arranged side by side on the axially other side (-Y side) of the plate 38. This reduces the cogging torque and torque ripple. The two first core piece parts 37A are located at the same position relative to each other in the circumferential direction. The two second core piece parts 37B are located at the same position relative to each other in the circumferential direction. The two third core piece parts 37C are located at the same position relative to each other in the circumferential direction. Each of the first core piece parts 37A, each of the second core piece parts 37B, and each of the third core piece parts 37C has a pair of the second fitting parts 32 described above.

In this specification, "the core piece parts 37 are arranged with a circumferential offset from each other" means that the circumferential positions of the magnetic pole parts 10P described below are offset between one core piece part 37 and the other core piece part 37. Also, in this specification, "the core piece parts 37 are located at the same positions in the circumferential direction" means that the circumferential positions of the magnetic pole parts 10P in one core piece part 37 and the circumferential positions of the magnetic pole parts 10P in the other core piece part 37 are the same.

As shown in FIG. 3, the rotor core 30 has a plurality of magnet holding portions 31 arranged in a line in the circumferential direction. The plurality of magnet holding portions 31 are provided on the radially outer portion of the rotor core 30. The plurality of magnet holding portions 31 are provided for each core piece portion 37. In each core piece portion 37, the plurality of magnet holding portions 31 are arranged at equal intervals around one circumferential circumference. In this embodiment, eight magnet holding portions 31 are provided for each core piece portion 37. The number of magnet holding portions 31 is not particularly limited.

The magnet holding parts 31 each have a pair of first magnet holes 51a, 51b adjacent to each other in the circumferential direction, and a pair of second magnet holes 52a, 52b located radially outside the pair of first magnet holes 51a, 51b and adjacent to each other in the circumferential direction. That is, the rotor core 30 has a pair of first magnet holes 51a, 51b and a pair of second magnet holes 52a, 52b. Thus, in this embodiment, each magnet holding part 31 is provided with a total of four magnet holes, a pair of first magnet holes 51a, 51b and a pair of second magnet holes 52a, 52b. In this embodiment, the pair of first magnet holes 51a, 51b and the pair of second magnet holes 52a, 52b penetrate each core piece part 37 in the axial direction. Note that the pair of first magnet holes 51a, 51b and the pair of second magnet holes 52a, 52b may be holes having bottoms at the axial ends.

A magnet 40 is disposed in each of the four magnet holes 50 in each magnet holding portion 31. The type of magnet 40 is not particularly limited. The magnet 40 may be, for example, a neodymium magnet or a ferrite magnet. The magnet 40 is, for example, a rectangular parallelepiped that is long in the axial direction. The magnet 40 extends, for example, from one axial end of each core piece portion 37 to the other axial end.

The magnets 40 include a pair of first magnets 41a, 41b arranged in a pair of first magnet holes 51a, 51b, respectively, and a pair of second magnets 42a, 42b arranged in a pair of second magnet holes 52a, 52b, respectively. Each magnet 40 is fixed in each magnet hole 50. The method of fixing each magnet 40 in each magnet hole 50 is not particularly limited. For example, each magnet 40 may be fixed in each magnet hole 50 by crimping a part of the rotor core 30, or may be fixed in each magnet hole 50 by resin filled in the part of each magnet hole 50 other than the part where the magnet 40 is arranged, or may be fixed in each magnet hole 50 by a foam sheet arranged in the part of each magnet hole 50 other than the part where the magnet 40 is arranged.

The rotor 10 has a number of magnetic pole portions 10P arranged in a line in the circumferential direction. In this embodiment, eight magnetic pole portions 10P are provided for each core piece part 37. That is, each first core piece part 37A, each second core piece part 37B, and each third core piece part 37C each has a number of magnetic pole portions 10P arranged in a line in the circumferential direction. The number of magnetic pole portions 10P is not particularly limited. In each core piece part 37, the multiple magnetic pole portions 10P are arranged at equal intervals around one circumferential circumference. In this embodiment, each magnetic pole portion 10P is composed of one magnet holding part 31 and a number of magnets 40 arranged in a number of magnet holes 50 provided in one magnet holding part 31. The magnetic pole portion 10P has a pair of first magnet holes 51a, 51b, a pair of second magnet holes 52a, 52b, a pair of first magnets 41a, 41b located in the pair of first magnet holes 51a, 51b, respectively, and a pair of second magnets 42a, 42b located in the pair of second magnet holes 52a, 52b.

In each core piece part 37, the multiple magnetic pole parts 10P include multiple magnetic pole parts 10N with north poles on the outer peripheral surface of the rotor core 30, and multiple magnetic pole parts 10S with south poles on the outer peripheral surface of the rotor core 30. In each core piece part 37 of this embodiment, four magnetic pole parts 10N and four magnetic pole parts 10S are provided. The four magnetic pole parts 10N and the four magnetic pole parts 10S are arranged alternately in the circumferential direction. The magnetic pole parts 10N and the magnetic pole parts 10S have the same configuration, except that the magnetic poles on the outer peripheral surface of the rotor core 30 are different and that they are located at different circumferential positions.

In the magnetic pole portion 10P, the first magnet hole 51a and the first magnet hole 51b are arranged on either side of the first virtual line Ld in the circumferential direction. The first virtual line Ld is a virtual line that passes through the circumferential center between the pair of first magnet holes 51a, 51b and extends in the radial direction. The first virtual line Ld is a magnetic pole center line that passes through the circumferential center of the magnetic pole portion 10P. The circumferential center of the magnetic pole portion 10P is the circumferential center of the magnet holding portion 31. The first virtual line Ld passes through the central axis J when viewed in the axial direction. The first virtual line Ld is provided for each magnetic pole portion 10P. When viewed in the axial direction, the first virtual line Ld passes on the d-axis of the rotor 10. The direction in which the first virtual line Ld extends is the d-axis direction of the rotor 10. When viewed in the axial direction, the first magnet hole 51a and the first magnet hole 51b are arranged in line symmetry with the first virtual line Ld as the axis of symmetry.

The pair of first magnet holes 51a, 51b extend in a direction that separates them from each other in the circumferential direction as they move from the radially inner side to the radially outer side when viewed in the axial direction. In other words, the circumferential distance between the first magnet holes 51a and 51b increases as they move from the radially inner side to the radially outer side. The pair of first magnet holes 51a, 51b are arranged along a V-shape that widens in the circumferential direction as they move radially outward when viewed in the axial direction.

As shown in FIG. 5, the first magnet hole 51a has a magnet accommodating hole portion 51c, an inner hole portion 51d, and an outer hole portion 51e. The magnet accommodating hole portion 51c is a rectangular hole that is long in the direction in which the first magnet hole 51a extends when viewed in the axial direction. The inner hole portion 51d is connected to the radially inner end of the end of the magnet accommodating hole portion 51c in the direction in which the magnet accommodating hole portion 51c extends when viewed in the axial direction. The outer hole portion 51e is connected to the radially outer end of the end of the magnet accommodating hole portion 51c in the direction in which the magnet accommodating hole portion 51c extends when viewed in the axial direction.

The first magnet hole 51b has a magnet accommodating hole portion 51f, an inner hole portion 51g, and an outer hole portion 51h. The magnet accommodating hole portion 51f is a rectangular hole that is long in the direction in which the first magnet hole 51b extends when viewed in the axial direction. The inner hole portion 51g is connected to the radially inner end of the end of the magnet accommodating hole portion 51f in the direction in which the magnet accommodating hole portion 51f extends when viewed in the axial direction. The outer hole portion 51h is connected to the radially outer end of the end of the magnet accommodating hole portion 51f in the direction in which the magnet accommodating hole portion 51f extends when viewed in the axial direction.

The inner hole portion 51d and the inner hole portion 51g are arranged circumferentially spaced apart from each other across the first virtual line Ld. When viewed in the axial direction, the inner hole portion 51d and the inner hole portion 51g are each substantially arc-shaped with the edge portion closer to the other inner hole portion being concave toward the other inner hole portion.

The pair of first magnets 41a, 41b arranged in the pair of first magnet holes 51a, 51b are arranged along a V-shape that expands in the circumferential direction as it moves radially outward when viewed in the axial direction. The first magnet 41a is arranged in the magnet accommodating hole portion 51c of the first magnet hole 51a. The first magnet 41b is arranged in the magnet accommodating hole portion 51f of the first magnet hole 51b. The inner holes 51d, 51g and the outer holes 51e, 51h are, for example, hollow portions, and each constitutes a flux barrier portion. The inner holes 51d, 51g and the outer holes 51e, 51h may be filled with a non-magnetic material such as resin, and the flux barrier portion may be constituted by each hole and the non-magnetic material such as resin filled in each hole. In this specification, the "flux barrier portion" is a portion that can suppress the flow of magnetic flux. In other words, magnetic flux does not easily pass through each flux barrier portion.

The pair of second magnet holes 52a, 52b are located radially outside the pair of first magnet holes 51a, 51b, respectively. The second magnet hole 52a is located radially outside the first magnet hole 51a. The second magnet hole 52b is located radially outside the first magnet hole 51b. The pair of second magnet holes 52a, 52b are arranged circumferentially between the pair of first magnet holes 51a, 51b. More specifically, the pair of second magnet holes 52a, 52b are arranged circumferentially between the outer hole portions 51e, 51h of the pair of first magnet holes 51a, 51b.

In the magnetic pole portion 10P, the second magnet hole 52a and the second magnet hole 52b are arranged on either side of the first virtual line Ld in the circumferential direction. That is, the first virtual line Ld passes between the pair of second magnet holes 52a, 52b when viewed in the axial direction. In this embodiment, the first virtual line Ld passes through the circumferential center between the pair of second magnet holes 52a, 52b when viewed in the axial direction. The second magnet hole 52a and the second magnet hole 52b are arranged in line symmetry with the first virtual line Ld as the axis of symmetry when viewed in the axial direction.

The pair of second magnet holes 52a, 52b extend in a direction that separates them from each other in the circumferential direction as they move from the radially inner side to the radially outer side when viewed in the axial direction. In other words, the circumferential distance between the second magnet holes 52a and the second magnet holes 52b increases from the radially inner side to the radially outer side when viewed in the axial direction. The pair of second magnet holes 52a, 52b are arranged along a V shape that widens in the circumferential direction as they move radially outward when viewed in the axial direction. When viewed in the axial direction, the inclination of the direction in which the pair of second magnet holes 52a, 52b extend relative to the radial direction is greater than the inclination of the direction in which the pair of first magnet holes 51a, 51b extend relative to the radial direction. The opening angle of the V shape formed by the pair of second magnet holes 52a, 52b is greater than the opening angle of the V shape formed by the pair of first magnet holes 51a, 51b.

The second magnet hole 52a has a magnet accommodating hole portion 52c, an inner hole portion 52d, and an outer hole portion 52e. The magnet accommodating hole portion 52c is a rectangular hole that is long in the direction in which the second magnet hole 52a extends when viewed in the axial direction. The inner hole portion 52d is connected to the radially inner end of the end of the magnet accommodating hole portion 52c in the direction in which the magnet accommodating hole portion 52c extends when viewed in the axial direction. The outer hole portion 52e is connected to the radially outer end of the end of the magnet accommodating hole portion 52c in the direction in which the magnet accommodating hole portion 52c extends when viewed in the axial direction.

The second magnet hole 52b has a magnet accommodating hole portion 52f, an inner hole portion 52g, and an outer hole portion 52h. The magnet accommodating hole portion 52f is a rectangular hole that is long in the direction in which the second magnet hole 52b extends when viewed in the axial direction. The inner hole portion 52g is connected to the radially inner end of the end portion of the magnet accommodating hole portion 52f in the direction in which the magnet accommodating hole portion 52f extends when viewed in the axial direction. The outer hole portion 52h is connected to the radially outer end of the end portion of the magnet accommodating hole portion 52f in the direction in which the magnet accommodating hole portion 52f extends when viewed in the axial direction.

The inner hole portion 52d and the inner hole portion 52g are arranged with a circumferential gap therebetween, sandwiching the first imaginary line Ld in the circumferential direction. The circumferential gap between the inner hole portion 52d and the inner hole portion 52g is smaller than the circumferential gap between the inner hole portion 51d and the inner hole portion 51g. When viewed in the axial direction, the edges of the inner hole portion 52d and the inner hole portion 52g that are closer to the other inner hole portion extend linearly along the first imaginary line Ld. The radial inner ends of the inner hole portions 52d and 52g are located radially outward of the radial inner ends of the magnet accommodating holes 52c and 52f.

The pair of second magnets 42a, 42b arranged in the pair of second magnet holes 52a, 52b are arranged along a V-shape that expands in the circumferential direction as it moves radially outward when viewed in the axial direction. That is, in each magnetic pole portion 10P of this embodiment, two pairs of magnets 40 arranged along a V-shape when viewed in the axial direction are arranged side by side in the radial direction. The second magnet 42a is arranged in the magnet accommodating hole portion 52c of the second magnet hole 52a. The second magnet 42b is arranged in the magnet accommodating hole portion 52f of the second magnet hole 52b. The inner holes 52d, 52g and the outer holes 52e, 52h are, for example, hollow portions, and each constitutes a flux barrier portion. The inner holes 52d, 52g and the outer holes 52e, 52h may be filled with a non-magnetic material such as resin, and the flux barrier portion may be constituted by each hole and a non-magnetic material such as resin filled in each hole.

In this specification, the "direction in which the magnet hole extends when viewed in the axial direction" refers to the direction in which the long side of the rectangular magnet accommodating hole portion extends when viewed in the axial direction, for example, when the magnet accommodating hole portion in which the magnet is accommodated is rectangular when viewed in the axial direction, such as the first magnet holes 51a and 51b in this embodiment. In other words, for example, in this embodiment, the "direction in which the first magnet hole 51a extends when viewed in the axial direction" refers to the direction in which the long side of the rectangular magnet accommodating hole portion 51c extends when viewed in the axial direction.

The rotor core 30 has a core flow passage portion 35. In this embodiment, the core flow passage portion 35 is located in a portion surrounded by a pair of first magnet holes 51a, 51b and a pair of second magnet holes 52a, 52b when viewed in the axial direction. The core flow passage portion 35 is located between the pair of first magnet holes 51a, 51b in the circumferential direction. Oil O flows as a refrigerant in the core flow passage portion 35 through a flow passage 90 described later. One core flow passage portion 35 is provided in each of the multiple magnet holding portions 31 provided in each core piece portion 37. That is, each of the first core piece portions 37A, each of the second core piece portions 37B, and each of the third core piece portions 37C has multiple core flow passage portions 35. As shown in FIG. 4, the core flow passage portion 35 extends in the axial direction. In this embodiment, the core flow passage portion 35 penetrates the core piece portion 37 in the axial direction. The core flow passage portion 35 may be a hole having a bottom in the axial direction.

As shown in FIG. 3, the core flow passage portion 35 is provided at a position overlapping with the first virtual line Ld when viewed in the axial direction. In each magnet holding portion 31, the first virtual line Ld is provided at a position dividing the core flow passage portion 35 in the circumferential direction. In this embodiment, the core flow passage portion 35 has an asymmetric shape with the first virtual line Ld in between when viewed in the axial direction. When viewed in the axial direction, the core flow passage portion 35 has an approximately V-shape with both sides of the first virtual line Ld bent radially outward. The width of the core flow passage portion 35 extending in an approximately V-shape when viewed in the axial direction is the same over almost the entirety. The first portion 35a of the core flow passage portion 35 located on one circumferential side (+θ side) of the first virtual line Ld extends obliquely from the first virtual line Ld in a direction inclined radially outward with respect to one circumferential side (+θ side direction) when viewed in the axial direction. The first portion 35a is located radially outside the first magnet hole 51a and radially inside the second magnet hole 52a.

The second portion 35b of the core flow passage portion 35, which is located on the other circumferential side (-θ side) of the first imaginary line Ld, extends obliquely from the first imaginary line Ld in a direction that is inclined radially outward with respect to the other circumferential side direction (-θ side direction) when viewed in the axial direction. When viewed in the axial direction, the dimension of the second portion 35b in the direction in which the second portion 35b extends is larger than the dimension of the first portion 35a in the direction in which the first portion 35a extends. The second portion 35b is located radially outward of the first magnet hole 51b and radially inward of the second magnet hole 52b. In a cross section perpendicular to the axial direction, the cross-sectional area of the second portion 35b is larger than the cross-sectional area of the first portion 35a.

The rotor core 30 has a hole 36 that overlaps with the second virtual line Lq when viewed in the axial direction. The second virtual line Lq is a virtual line that extends radially through the center between the magnetic pole portions 10P that are adjacent in the circumferential direction when viewed in the axial direction. The second virtual line Lq passes through the center axis J when viewed in the axial direction. The second virtual line Lq passes through the q axis of the rotor 10 when viewed in the axial direction. The second virtual line Lq extends in the q axis direction of the rotor 10. The second virtual line Lq is provided between each pair of magnet holding portions 31. The direction in which the first virtual line Ld extends and the direction in which the second virtual line Lq extends intersect with each other. The first virtual line Ld and the second virtual line Lq are provided alternately along the circumferential direction.

A plurality of holes 36 are provided at intervals in the circumferential direction for each core piece part 37. In this embodiment, eight holes 36 are provided for each core piece part 37. In this embodiment, the holes 36 are holes that penetrate the core piece part 37 in the axial direction. The holes 36 may be holes that have a bottom in the axial direction. Each hole 36 is disposed radially inward between circumferentially adjacent magnet holding parts 31. Each hole 36 is located radially inward between the first magnet hole 51a in one magnet holding part 31 and the first magnet hole 51b in the other magnet holding part 31 among the circumferentially adjacent magnet holding parts 31.

In this embodiment, the hole portion 36 has a generally triangular shape with rounded corners that protrude radially outward when viewed in the axial direction. When viewed in the axial direction, a second imaginary line Lq passes through the circumferential center of the hole portion 36. In this embodiment, when viewed in the axial direction, the hole portion 36 has a shape that is line-symmetrical with the second imaginary line Lq that passes through the hole portion 36 as the axis of symmetry. The multiple holes 36 are, for example, hollow portions, and each of them constitutes a flux barrier portion. The multiple holes 36 may be filled with a non-magnetic material such as resin, and a flux barrier portion may be formed by each hole portion 36 and the non-magnetic material such as resin filled in each hole portion 36.

As shown in FIG. 6, the rotor core 30 has a plurality of plate members 30a stacked in the axial direction. Each core piece section 37 is composed of a plurality of plate members 30a stacked in the axial direction. The plate members 30a are plate-shaped members whose plate surfaces face in the axial direction. The plate members 30a are substantially annular about the central axis J. The material of the plate members 30a is rolled steel material produced by rolling in a predetermined direction. The material of the plate members 30a is, for example, an electromagnetic steel plate.

Axially adjacent plate members 30a are fixed to each other by crimped portions 30b, which are formed by crimping a portion of the plate member 30a in the axial direction. In this embodiment, the crimped portions 30b are formed by plastically deforming a portion of the plate member 30a toward the other axial side (-Y side). The crimped portions 30b protrude toward the other axial side. By providing the crimped portions 30b, a crimped recess 30c recessed in the axial direction is provided on the axial surface of the plate member 30a facing the opposite side (+Y side) from the side where the crimped portions 30b protrude. In the axially adjacent plate members 30a, one plate member 30a is fixed to the other plate member 30a by fitting the crimped portions 30b into the crimped recesses 30c provided in the other plate member 30a.

As shown in FIG. 5, the crimping portion 30b is provided at intervals in the circumferential direction. The crimping portion 30b is provided between the magnetic pole portions 10P adjacent in the circumferential direction. The crimping portion 30b is located between the first magnet hole 51a of one magnetic pole portion 10P and the first magnet hole 51b of the other magnetic pole portion 10P adjacent in the circumferential direction. In this embodiment, the crimping portion 30b is provided at a position shifted in the circumferential direction with respect to the second virtual line Lq. In the example of FIG. 5, the crimping portion 30b is located on one circumferential side (+θ side) of the second virtual line Lq. In this embodiment, the crimping portion 30b is rectangular when viewed in the axial direction. The shape of the crimping portion 30b when viewed in the axial direction is not particularly limited, and may be a polygonal shape other than a rectangular shape, or may be a circular shape.

3, the circumferential center of the first fitting portion 21 and the circumferential center of the second fitting portion 32 are arranged circumferentially offset with respect to the first imaginary line Ld that passes through the circumferential center of the magnetic pole portion 10P and extends in the radial direction. As a result, when a plate member 30a having the same shape as a plate member 30a constituting a certain core piece part 37 is inverted in the axial direction and then the portion constituting the second fitting portion 32 provided on the plate member 30a is arranged to overlap the second fitting portion 32 of the certain core piece part 37 in the axial direction, the portion constituting the magnetic pole portion 10P provided on the plate member 30a can be arranged circumferentially offset with respect to the magnetic pole portion 10P of the certain core piece part 37. Therefore, using plate members 30a of the same shape, two types of core piece parts 37 in which the circumferential positions of the second fitting portions 32 are the same and the magnetic pole portions 10P are offset from each other in the circumferential direction can be made. This makes it easier to reduce the number of types of molds required to make the plate member 30a, and helps prevent increases in the manufacturing costs of producing the rotor core 30.

In this embodiment, the circumferential center of the first fitting portion 21 and the circumferential center of the second fitting portion 32 are shifted to one circumferential side (+θ side) with respect to the first virtual line Ld. In FIG. 3, a third virtual line L3 is shown that passes through the circumferential center of the first fitting portion 21 and the circumferential center of the second fitting portion 32 and extends in the radial direction when viewed in the axial direction. The third virtual line L3 is slightly shifted to one circumferential side with respect to the first virtual line Ld. The third virtual line L3 is located between the first virtual line Ld and the second virtual line Lq in the circumferential direction. The circumferential angle formed by the first virtual line Ld and the third virtual line L3 is smaller than the circumferential angle formed by the second virtual line Lq and the third virtual line L3. In this embodiment, the first virtual line Ld and the third virtual line L3 overlap with the first fitting portion 21 and the second fitting portion 32 when viewed in the axial direction.

As shown in FIG. 4, the plate 38 is disposed between the first core piece parts 37A that are adjacent to each other in the axial direction. The plate 38 is annular and surrounds the shaft 20. More specifically, the plate 38 is annular about the central axis J. The shaft 20 is fitted to the radially inner side of the plate 38. The plate 38 is plate-shaped with the plate surface facing the axial direction. The material constituting the plate 38 is non-magnetic. Therefore, it is possible to suppress the generation of eddy currents in the plate 38. This makes it possible to reduce losses due to eddy currents generated in the rotor 10 compared to when the plate 38 is made of a magnetic material. The outer diameter of the plate 38 is, for example, approximately the same as the outer diameter of the rotor core 30.

The plate 38 has a plate flow passage portion 38a that connects the second shaft hole portion 22b and the core flow passage portion 35. In this embodiment, the plate flow passage portion 38a is configured by a hole that penetrates the plate 38 in the axial direction. The plate flow passage portion 38a extends radially outward from the radial inner edge portion of the annular plate 38. The radially inner end portion of the plate flow passage portion 38a opens radially inward. Although not shown in the figure, multiple plate flow passage portions 38a are provided at intervals in the circumferential direction. The multiple plate flow passage portions 38a are arranged at equal intervals around one circumferential circumference.

As shown in FIG. 1, a pair of end plates 80 are provided, sandwiching the rotor core 30 in the axial direction. The pair of end plates 80 includes an end plate 80a located on the other axial side (-Y side) of the rotor core 30, and an end plate 80b located on one axial side (+Y side) of the rotor core 30. The end plate 80a and the end plate 80b are fixed to the rotor core 30. In this embodiment, with the end plate 80b abutting against the flange portion 20b from the other axial side, the nut 39a located on the other axial side of the end plate 80a is tightened into a threaded portion (not shown) provided on the outer peripheral surface of the shaft 20 to press the end plate 80a against the rotor core 30, thereby fixing the pair of end plates 80a, 80b to the rotor core 30. The pair of end plates 80a, 80b, the rotor core 30, and the plate 38 are sandwiched in the axial direction by the flange portion 20b and the nut 39a, and are fixed in the axial direction. As shown in FIG. 7, an annular washer 39b that surrounds the shaft 20 is provided axially between the end plate 80a and the nut 39a.

In the following description, the side closer to the center of the rotor core 30 in the axial direction with respect to a certain object may be referred to as the "axial inner side," and the side farther from the center of the rotor core 30 in the axial direction may be referred to as the "axial outer side." In this embodiment, the axial inner side corresponds to the "first side," and the axial outer side corresponds to the "second side." In end plate 80a, the axial inner side is one axial side (+Y side), and the axial outer side is the other axial side (-Y side). In end plate 80b, the axial inner side is the other axial side, and the axial outer side is one axial side. The pair of end plates 80a, 80b are each located on the axial outer side of the rotor core 30.

End plate 80a is in contact with the third core piece part 37C located on the other axial side (-Y side) of the two third core piece parts 37C. End plate 80b is in contact with the third core piece part 37C located on one axial side (+Y side) of the two third core piece parts 37C. In other words, in this embodiment, the third core piece part 37C is a core piece part 37 that has a core flow passage part 35 and is in axial contact with the end plate 80. In the following description, the relative positional relationship between the core piece part 37 and the end plates 80a, 80b is the relative positional relationship between the third core piece part 37C and the end plates 80a, 80b, unless otherwise specified.

The pair of end plates 80a, 80b are fixed to the rotor core 30 with at least a portion of them elastically deformed in the axial direction. In this embodiment, the pair of end plates 80a, 80b are fixed to the rotor core 30 with the radially outer portions of the plate body portion 81, which will be described later, elastically deformed in the axial direction.

In this embodiment, end plate 80a and end plate 80b have the same shape. End plate 80a and end plate 80b are inverted relative to each other in the axial direction. In the following explanation, end plate 80a will be explained as a representative of the pair of end plates 80a, 80b, and explanation of end plate 80b may be omitted.

7 and 8, the end plate 80a is annular and surrounds the central axis J. More specifically, the end plate 80a is generally annular and centered on the central axis J. As shown in FIG. 9, the shaft 20 is fitted into the radially inner side of the end plate 80a. In this embodiment, the shaft 20 is press-fitted into the radially inner side of the end plate 80a. The end plate 80a has a plate main body portion 81 and a protruding wall portion 82. The plate main body portion 81 is generally annular and centered on the central axis J. The plate main body portion 81 is plate-shaped with the plate surface facing the axial direction. The plate main body portion 81 has a large diameter portion 81a and a small diameter portion 81b. The large diameter portion 81a is the axially inner portion (+Y side) of the plate main body portion 81. The small diameter portion 81b is the axially outer portion (-Y side) of the plate main body portion 81. The outer diameter of the small diameter portion 81b is smaller than the outer diameter of the large diameter portion 81a.

As shown in FIG. 7, a third fitting portion 89 that protrudes radially inward is provided on the radial inner edge of the plate main body portion 81. In other words, the end plate 80a has a third fitting portion 89. A pair of third fitting portions 89 are provided on either side of the central axis J in the radial direction. The pair of third fitting portions 89 are respectively fitted into a pair of first fitting portions 21 on the shaft 20. This allows the shaft 20 and the end plate 80a to hook onto each other in the circumferential direction, preventing the shaft 20 and the end plate 80a from rotating relative to each other in the circumferential direction. The third fitting portion 89 is substantially rectangular when viewed in the axial direction.

Each of the pair of third fitting portions 89 overlaps with each of the pair of second fitting portions 32 in the axial direction. As shown in FIG. 5, the circumferential center of the third fitting portion 89 is arranged to be shifted in the circumferential direction with respect to the first virtual line Ld. When viewed in the axial direction, the above-mentioned third virtual line L3 passes through the circumferential center of the third fitting portion 89. In this embodiment, the circumferential center of the third fitting portion 89 is shifted to one circumferential side (+θ side) with respect to the first virtual line Ld.

Note that, for example, in a configuration in which the second fitting portion 32 provided on the inner edge of the hole 30h is recessed radially outward and the first fitting portion 21 provided on the outer circumferential surface of the shaft 20 protrudes radially outward, the third fitting portion 89 can also be recessed radially outward and fitted into the first fitting portion 21. In this case, the first fitting portion 21 is fitted into the third fitting portion 89. Even in this case, it is possible to prevent the shaft 20 and the end plate 80a from rotating relative to each other in the circumferential direction.

As shown in FIG. 7, the protruding wall portion 82 protrudes axially outward from the axially outer (-Y side) surface of the plate body portion 81, i.e., the second plate surface 87 described later. In this embodiment, the protruding wall portion 82 is located radially outward from the radial center between the radially inner edge portion of the end plate 80a and the radially outer edge portion of the end plate 80a. The protruding wall portion 82 protrudes axially outward from the radially outer end portion of the small diameter portion 81b. In this embodiment, the protruding wall portion 82 is annular and surrounds the central axis J. More specifically, the protruding wall portion 82 is annular and centered on the central axis J. By removing a portion of the protruding wall portion 82 by cutting, the circumferential balance of the rotor 10 can be adjusted.

As shown in FIG. 5, the radially inner end of the protruding wall portion 82 is located radially outward of the entire core flow passage portion 35 excluding the radially outer end of the second portion 35b. The radially inner end of the protruding wall portion 82 may be located radially outward of the entire core flow passage portion 35. The protruding wall portion 82 axially overlaps the radially outer ends of the pair of first magnets 41a, 41b and the entire pair of second magnets 42a, 42a excluding the radially outer ends. The shape of the protruding wall portion 82 is not particularly limited and may be a shape other than annular. For example, the protruding wall portion 82 may be C-shaped when viewed in the axial direction.

As shown in FIG. 9, the end plate 80a has a first plate surface 86 that faces the rotor core 30 in the axial direction, and a second plate surface 87 that faces the opposite side to the first plate surface 86. The first plate surface 86 is the surface on the axially inner side (+Y side) of the plate main body portion 81. The second plate surface 87 is the surface on the axially outer side (-Y side) of the plate main body portion 81. In other words, the plate main body portion 81 has a first plate surface 86 and a second plate surface 87.

The first plate surface 86 has a contact surface 86e that contacts the rotor core 30 in the axial direction when at least a portion of the end plate 80a is elastically deformed in the axial direction. The contact surface 86e is the surface of the first plate surface 86 that contacts the axially outer (-Y side) surface of the rotor core 30 when the end plate 80a is fixed to the rotor core 30. In this embodiment, the contact surface 86e contacts the axially outer surface of the third core piece part 37C. The contact surface 86e has a first surface 86a. In this embodiment, the contact surface 86e consists of the first surface 86a.

The first surface 86a faces inward in the axial direction (+Y side). As shown in FIG. 8, the first surface 86a is an annular surface surrounding the central axis J. More specifically, the first surface 86a is an approximately annular surface centered on the central axis J. The end plate 80a shown in FIG. 10 is in a state before being fixed to the rotor core 30 and is not elastically deformed. As shown in FIG. 10, when the end plate 80a is not elastically deformed, the first surface 86a is an inclined surface that is located on the first side where the rotor core 30 is positioned relative to the end plate 80a in the axial direction, that is, on the axially inner side (+Y side), as it moves radially outward.

When the end plate 80a is not elastically deformed, the radially outer end of the first surface 86a is the part of the contact surface 86e located on the innermost axial side (+Y side). Therefore, when the end plate 80a is fixed to the rotor core 30, if the end plate 80a is moved axially toward the rotor core 30 from the axially outer side (-Y side), the radially outer end of the first surface 86a first comes into contact with the axially outer surface of the rotor core 30. The end plate 80a is pressed axially inward by the nut 39a and pressed against the rotor core 30, so that the part of the end plate 80a having the first surface 86a elastically deforms in the axial direction. As a result, as shown in FIG. 9, the first surface 86a becomes flat perpendicular to the axial direction, and the entire first surface 86a comes into contact with the axially outer surface of the rotor core 30. As a result, a restoring force in the axially inward direction is applied to the rotor core 30 from the end plate 80a. Therefore, the multiple plate members 30a that make up the rotor core 30 can be held in the axial direction, preventing problems such as some of the plate members 30a being turned over.

The first surface 86a is located radially outward from the radial center between the radial inner edge of the end plate 80a and the radial outer edge of the end plate 80a. In this embodiment, the radially outer end of the first surface 86a is the radially outer end of the first plate surface 86. Therefore, the first surface 86a can easily hold the radially outer portion of the rotor core 30 in the axial direction. This makes it possible to more effectively prevent the radial outer edge of the plate member 30a from curling up.

As shown in FIG. 5, the radially inner end 86f of the first surface 86a is located radially inner than the core flow passage portion 35. Therefore, the first surface 86a can press at least a part of the peripheral portion of the core flow passage portion 35 on the axially outer surface of the rotor core 30. This can prevent the oil O flowing in the core flow passage portion 35 from leaking axially between the rotor core 30 and the end plate 80a. In this embodiment, the first surface 86a covers and blocks almost the entire second portion 35b of the core flow passage portion 35 from the axially outer side. The end 86f is located radially outer than the radially inner ends of the pair of first magnet holes 51a, 51b. The first surface 86a is located radially outer than the hole portion 36.

The first surface 86a overlaps in the axial direction with the radially outer portions of the pair of first magnet holes 51a, 51b, the radially outer portions of the pair of first magnets 41a, 41b, the entire pair of second magnet holes 52a, 52b, and the entire pair of second magnets 42a, 42a. Thus, in this embodiment, the first surface 86a overlaps in the axial direction with at least a portion of each of the magnets 40 arranged in each magnet hole 50 of the third core piece part 37C. Therefore, the first surface 86a can effectively prevent each magnet 40 from protruding axially outward from within each magnet hole 50.

As shown in FIG. 9, the first plate surface 86 has a second surface 86b located radially inward of the first surface 86a. The second surface 86b faces the axially inward (+Y side). The second surface 86b is located on the second side where the end plate 80a is disposed relative to the rotor core 30 in the axial direction, that is, on the axially outer side (-Y side), from the radially inner end of the first surface 86a. As shown in FIG. 8, the second surface 86b is an annular surface surrounding the central axis J. More specifically, the second surface 86b is an annular surface centered on the central axis J. The second surface 86b is connected to the radially inner side of the first surface 86a via an annular stepped surface 86g. As shown in FIG. 10, the stepped surface 86g is a curved surface located radially inward as it moves axially outward. When the end plate 80a is not elastically deformed, the second surface 86b is a flat surface perpendicular to the axial direction. When the end plate 80a is elastically deformed, the second surface 86b may be deformed in any manner.

The first plate surface 86 has a third surface 86c located radially inwardly away from the second surface 86b. The third surface 86c faces inwardly in the axial direction (+Y side). The third surface 86c is located axially outwardly (-Y side) from the first surface 86a and axially inwardly (+Y side) from the second surface 86b. As shown in FIG. 8, the third surface 86c is an annular surface surrounding the central axis J. More specifically, the third surface 86c is an approximately annular surface centered on the central axis J. The radially inner end of the third surface 86c is the radially inner end of the first plate surface 86. As shown in FIG. 10, when the end plate 80a is not elastically deformed, the third surface 86c is a flat surface perpendicular to the axial direction. Note that when the end plate 80a is elastically deformed, the third surface 86c may be deformed in any manner.

The first plate surface 86 has a convex portion 86d that protrudes in the axial direction. In other words, the end plate 80a has a convex portion 86d. The convex portion 86d protrudes inward in the axial direction (+Y side). As shown in FIG. 8, in this embodiment, the convex portion 86d is annular and surrounds the central axis J. More specifically, the convex portion 86d is annular and centered on the central axis J. The convex portion 86d is located radially inward from the second surface 86b. In this embodiment, the convex portion 86d is located radially between the second surface 86b and the third surface 86c. The second surface 86b and the third surface 86c are connected to each other via the convex portion 86d.

As shown in FIG. 9, the axially inner end face (+Y side) of the convex portion 86d is located axially outer (-Y side) than the first surface 86a, and axially inner than the second surface 86b and the third surface 86c. As shown in FIG. 10, when the end plate 80a is not elastically deformed, the axially inner end face of the convex portion 86d is a flat surface perpendicular to the axial direction. Note that when the end plate 80a is elastically deformed, the axially inner end face of the convex portion 86d may be deformed in any manner.

When the end plate 80a is not elastically deformed, the protrusion 86d is located axially outward (-Y side) from the radially inner end of the first surface 86a. As shown in FIG. 9, in this embodiment, even when the end plate 80a is elastically deformed in the axial direction, the protrusion 86d is located axially outward from the radially inner end of the first surface 86a. That is, in this embodiment, the axially inner end face of the protrusion 86d faces the axially outer surface of the rotor core 30 via a gap. The axially inner end face of the protrusion 86d may be in contact with the axially outer surface of the rotor core 30. The shape of the protrusion 86d is not particularly limited and may be a shape other than annular. The protrusion 86d may be, for example, C-shaped when viewed in the axial direction.

The second plate surface 87 is provided with a protruding portion 87c that protrudes axially outward (-Y side). The protruding portion 87c is located radially outward from the radial inner edge of the second plate surface 87 and radially inward from the radial outer edge of the second plate surface 87. As shown in FIG. 7, the protruding portion 87c is annular about the central axis J. The axially outer end of the protruding portion 87c is located axially inward (+Y side) from the axially outer end of the protruding wall portion 82. As shown in FIG. 9, the outer side surface 87a of the second plate surface 87 that is located radially outward from the protruding portion 87c is located axially outward from the inner side surface 87b of the second plate surface 87 that is located radially inward from the protruding portion 87c.

The axially outer surface of the protruding portion 87c is a pressure receiving surface 87d that receives an axially inward (+Y side) force from the nut 39a when the nut 39a is tightened. The pressure receiving surface 87d is a flat surface perpendicular to the axial direction. The pressure receiving surface 87d is annular about the central axis J. The pressure receiving surface 87d is the axially outer (-Y side) end of the protruding portion 87c, and is located axially inner than the axially outer end of the protruding wall portion 82. The axially inner surface of the washer 39b is in contact with the pressure receiving surface 87d. The axially inner surface of the nut 39a is in contact with the axially outer surface of the washer 39b. The pressure receiving surface 87d receives an axially inward force from the nut 39a via the washer 39b. When an axially inward force is applied to the pressure receiving surface 87d, the end plate 80a is pressed against the rotor core 30 and elastically deforms in the axial direction.

The end plate 80a has a first recess 83 provided on the outer surface of the end plate 80a. At least a portion of the first recess 83 overlaps with the first surface 86a in the axial direction. Therefore, by providing the first recess 83, the rigidity of the portion of the end plate 80a that overlaps with the first surface 86a in the axial direction can be reduced. This makes it easier to suitably elastically deform the portion of the end plate 80a that overlaps with the first surface 86a in the axial direction when the end plate 80a is pressed axially against the rotor core 30 and fixed. Therefore, the first surface 86a, which is inclined with respect to a plane perpendicular to the axial direction when the end plate 80a is not elastically deformed, can be easily deformed into a plane perpendicular to the axial direction, and the entire first surface 86a can be easily brought into contact with the rotor core 30. Therefore, the axial force applied from the end plate 80a to the rotor core 30 via the first surface 86a can be improved. This allows the multiple plate members 30a that make up the rotor core 30 to be appropriately held in the axial direction, and further prevents problems such as some of the plate members 30a being turned over. In this embodiment, the entire first recess 83 overlaps with the first surface 86a in the axial direction.

In this embodiment, the first recess 83 is recessed radially inward from the radially outer surface of the end plate 80a. Therefore, compared to when the first recess 83 is recessed in the axial direction, the portion located on the axially inner side (+Y side) of the first recess 83 can be easily elastically deformed axially outward (-Y side) toward the first recess 83. This makes it easier for the portion provided with the first surface 86a to be elastically deformed in the axial direction in a suitable manner so that the first surface 86a becomes a surface perpendicular to the axial direction. Therefore, the entire first surface 86a can be more easily brought into contact with the rotor core 30, and the axial force applied from the end plate 80a to the rotor core 30 can be further improved.

In this embodiment, the first recess 83 is recessed radially inward from the radially outer surface of the small diameter portion 81b of the plate body portion 81. In other words, in this embodiment, the first recess 83 is provided in the plate body portion 81. Therefore, compared to when the first recess 83 is provided in the protruding wall portion 82, a larger portion of the protruding wall portion 82 can be cut to adjust the circumferential balance of the rotor 10.

As shown in FIG. 7, in this embodiment, the first recess 83 is a groove extending in the circumferential direction. In this embodiment, the first recess 83 is annular and surrounds the central axis J. Therefore, the portion of the end plate 80a on which the first surface 86a is provided can be easily elastically deformed over the entire circumference, and the entire first surface 86a can be easily brought into favorable contact with the rotor core 30 over the entire circumference. This improves the axial force applied from the end plate 80a to the rotor core 30 over the entire circumference. In addition, compared to the case where the first recess 83 is provided on a portion of the end plate 80a in the circumferential direction, the first recess 83 is easier to create by cutting or the like. Therefore, the end plate 80a can be easily manufactured. In this embodiment, the first recess 83 is annular and centered on the central axis J.

As shown in FIG. 5, the radially inner end of the first recess 83 is located radially inner than the pair of second magnets 42a, 42b and radially outer than the core flow passage portion 35. At least a part of the first recess 83 overlaps with the magnet 40 in the axial direction. Therefore, the rigidity of the part of the end plate 80a that overlaps with the magnet 40 in the axial direction can be easily reduced by the first recess 83, and this part can be easily elastically deformed in a suitable manner. This allows the magnet 40 to be preferably held down from the axially outer side by the first surface 86a. In addition, the first surface 86a can be easily brought into contact with the peripheral portion of the magnet hole 50 in a suitable manner. Therefore, it is possible to prevent foreign matter such as oil O and iron powder from entering the magnet hole 50. In this embodiment, the first recess 83 overlaps with the radially outer ends of the pair of first magnets 41a, 41b and the entire pair of second magnets 42a, 42b except for the radially outer ends in the axial direction.

In this embodiment, at least a portion of the first recess 83 overlaps with the protruding wall portion 82 in the axial direction. Therefore, the provision of the first recess 83 makes it easy to reduce the rigidity of the portion of the end plate 80a where the protruding wall portion 82 is provided. This makes it possible to prevent the portion of the end plate 80a where the first surface 86a is provided from becoming difficult to elastically deform, even if the protruding wall portion 82 is provided at a position that overlaps with the first surface 86a in the axial direction.

Here, the more the protruding wall portion 82 is positioned radially outward, the larger the outer diameter of the protruding wall portion 82 can be, and therefore the longer the length of the protruding wall portion 82 extending in the circumferential direction can be. This makes it easier to finely adjust the circumferential balance of the rotor 10 when adjusting the circumferential balance of the rotor 10 by cutting a portion of the circumferential direction of the protruding wall portion 82. In addition, the more the first surface 86a is positioned radially outward, the more the radially outer end of the plate member 30a can be effectively prevented from turning over. In other words, it is preferable that both the protruding wall portion 82 and the first surface 86a are positioned radially outward. In this embodiment, as described above, the protruding wall portion 82 and the first surface 86a are positioned radially outward from the radial center between the radial inner edge portion of the end plate 80a and the radial outer edge portion of the end plate 80a. Therefore, the protruding wall portion 82 and the first surface 86a can be positioned radially outward, and the above-mentioned effects can be obtained. However, on the other hand, if both the protruding wall portion 82 and the first surface 86a are positioned radially outward, the portion of the end plate 80a where the first surface 86a is provided is less likely to elastically deform due to the presence of the protruding wall portion 82.

In contrast to this, in this embodiment, by providing the first recess 83 as described above, even if the protruding wall portion 82 is provided at a position that axially overlaps with the first surface 86a, it is possible to prevent the portion of the end plate 80a where the first surface 86a is provided from becoming difficult to elastically deform. In this way, the effect of a configuration in which at least a portion of the first recess 83 overlaps with the protruding wall portion 82 in the axial direction is more effectively obtained in a configuration in which the protruding wall portion 82 and the first surface 86a are located radially outward of the radial center between the radial inner edge portion of the end plate 80a and the radial outer edge portion of the end plate 80a.

In this specification, a "recess" may be a portion that is recessed in a certain direction and has a bottom surface portion located in the certain direction and at least a pair of side surfaces that face in a direction perpendicular to the certain direction. As shown in FIG. 9, for example, the first recess 83 is recessed in the radial direction and has a bottom surface portion 83a located on the radially inner side and a pair of side surfaces 83b, 83c that face in the axial direction perpendicular to the radial direction. By providing the first recess 83, which is a recess, in the end plate 80a, it is easier to thin the portion of the end plate 80a between the first surface 86a and the first recess 83 in the axial direction, compared to, for example, cutting out the end portion on the axial outer side of the end plate 80a to reduce the outer diameter at that end. This makes it easier to suitably reduce the rigidity of the portion of the end plate 80a where the first surface 86a is provided.

When the end plate 80a is fixed to the rotor core 30, the radially outer end of the inclined first surface 86a as shown in FIG. 10 comes into contact with the rotor core 30 first, and as the end plate 80a is pressed against the rotor core 30 and elastically deforms, the portion of the first surface 86a that is radially inner than the radially outer end comes into contact with the rotor core 30 successively. At this time, if the surface located on the radially inner side of the first surface 86a is located in the same axial position as the radially inner end of the first surface 86a or is located axially inner, there is a risk that the surface located on the radially inner side of the first surface 86a will come into contact with the rotor core 30 before the radially inner end of the first surface 86a comes into contact with the rotor core 30. In this case, there is a risk that the radially inner end of the first surface 86a and the like will be less likely to come into contact with the rotor core 30.

In contrast, in this embodiment, the first plate surface 86 has a second surface 86b located radially inward of the first surface 86a. The second surface 86b is located on the second side where the end plate 80a is disposed relative to the rotor core 30 in the axial direction, that is, on the axially outer side, from the radially inner end of the first surface 86a. Therefore, the second surface 86b located radially inward of the first surface 86a can be separated axially outward from the rotor core 30, and the second surface 86b can be prevented from contacting the rotor core 30 before the radially inner end of the first surface 86a contacts the rotor core 30. This can prevent the radially inner end of the first surface 86a from not contacting the rotor core 30. Therefore, the entire first surface 86a can be easily brought into contact with the rotor core 30, and the axial force applied from the end plate 80a to the rotor core 30 can be further improved.

When the end plate 80a is fixed to the rotor core 30 and elastically deformed, the second surface 86b is likely to deform, for example, into a curved shape that is concave outward in the axial direction. In this case, the larger the radial dimension of the second surface 86b, the more the second surface 86b is likely to deform in the axial direction, and the greater the stress that is generated in the second surface 86b.

In contrast, in this embodiment, the end plate 80a has a convex portion 86d that is provided on the first plate surface 86 and protrudes in the axial direction. The convex portion 86d is located radially inward from the second surface 86b. Therefore, the radial dimension of the second surface 86b can be made smaller than when, for example, the convex portion 86d is not provided and the second surface 86b is provided up to the radially inner end of the first plate surface 86. This makes it possible to suppress large deformation in the axial direction when the second surface 86b is deformed, and to suppress the stress generated in the second surface 86b from increasing. Therefore, it is possible to suppress the generation of a large load on the end plate 80a, and to suppress damage to the end plate 80a. In this embodiment, the second surface 86b and the third surface 86c arranged radially sandwiching the convex portion 86d each deform in the axial direction less than the deformation of the second surface 86b when the convex portion 86d is not provided, so that the first plate surface 86 can receive pressure in a suitably distributed manner.

In this embodiment, when the end plate 80a is not elastically deformed, the protrusion 86d is located on the second side, i.e., axially outward, of the radially inner end of the first surface 86a. Therefore, when the end plate 80a is fixed to the rotor core 30, the protrusion 86d can be prevented from contacting the rotor core 30 before the radially inner end of the first surface 86a contacts the rotor core 30. This can further prevent the radially inner end of the first surface 86a from contacting the rotor core 30. Therefore, it is possible to more suitably bring the entire first surface 86a into contact with the rotor core 30, and more suitably improve the axial force applied from the end plate 80a to the rotor core 30.

As described above, in this embodiment, the radially inner end of the third surface 86c is the radially inner end of the first plate surface 86. The third surface 86c is located axially outward (-Y side) from the radially inner end of the first surface 86a. Therefore, the third surface 86c can be prevented from contacting the rotor core 30. This can prevent the radially inner end of the first plate surface 86 from contacting the rotor core 30. Therefore, the radially inner end of the end plate 80a can be prevented from receiving force from the rotor core 30. Therefore, even if the shaft 20 is pressed into the radially inner side of the end plate 80a and the radially inner end of the end plate 80a receives force from the shaft 20, the load applied to the radially inner end of the end plate 80a can be prevented from becoming too large. This can prevent the radially inner end of the end plate 80a from being damaged.

9, the end plate 80a has a through hole 84 that penetrates the end plate 80a in the axial direction and is connected to the core flow passage portion 35 in the axial direction. The through hole 84 penetrates a portion of the end plate 80a that is located radially outward from the protruding portion 87c and radially inward from the protruding wall portion 82. The through hole 84 penetrates a portion of the end plate 80a that is located radially outward from the radially inner end of the first surface 86a. As shown in FIG. 8, in this embodiment, the through hole 84 is an elongated hole that extends linearly in a direction perpendicular to the radial direction when viewed in the axial direction. Both circumferential ends of the through hole 84 are arc-shaped that are concave in a direction away from each other in the circumferential direction when viewed in the axial direction.

The through holes 84 are provided at intervals in the circumferential direction. The through holes 84 are arranged at equal intervals around one circumference in the circumferential direction. In this embodiment, eight through holes 84 are provided. Each through hole 84 is axially connected to each core flow passage section 35 of the third core piece section 37C.

The through hole 84 has a first opening 84a that opens to the first surface 86a. As described above, in this embodiment, the first surface 86a can be suitably brought into contact with the rotor core 30, and therefore the peripheral portion of the first opening 84a of the first surface 86a can also be suitably brought into contact with the rotor core 30. This can prevent a portion of the oil O in the core flow passage portion 35 from leaking into the gap between the end plate 80a and the rotor core 30 without flowing into the first opening 84a, and can prevent a portion of the oil O that has flowed from the core flow passage portion 35 into the through hole 84 from flowing back and leaking from the first opening 84a into the gap between the end plate 80a and the rotor core 30. Therefore, it is possible to prevent the oil O from flowing into the magnet hole 50 through the gap between the end plate 80a and the rotor core 30. Therefore, it is possible to prevent the oil O that has flowed into the magnet hole 50 from causing a bias in the mass of the rotor 10, and to prevent the vibration of the rotor 10 from increasing. This can suppress the noise caused by the vibration of the drive device 100. In this embodiment, the first opening 84a opens to the radially inner portion of the first surface 86a.

9, the through hole 84 has a second opening 84b that opens into the second plate surface 87. The second opening 84b overlaps with the first opening 84a in the axial direction. The oil O that flows into the through hole 84 is discharged from the second opening 84b. The second recess 85 that is recessed in the axial direction is provided in the portion of the second plate surface 87 where the second opening 84b opens. In other words, the end plate 80a has the second recess 85 that is provided in the second plate surface 87 and recessed in the axial direction. At least a part of the second opening 84b opens to the inner surface of the second recess 85. Therefore, when the end plate 80a elastically deforms, the stress generated in the portion around the second opening 84b is easily distributed and received by the second recess 85. This makes it possible to make the second opening 84b less likely to deform. Therefore, it is possible to easily discharge the oil O stably from the second opening 84b.

As shown in FIG. 11, in this embodiment, the second opening 84b is entirely open to the inner surface of the second recess 85. Therefore, the stress generated in the second opening 84b can be more suitably distributed and received by the second recess 85. This makes it possible to further suppress deformation of the second opening 84b. In this embodiment, the second recess 85 has a generally elliptical shape extending in the circumferential direction when viewed in the axial direction. The second opening 84b is open to the inner surface of a portion of the second recess 85 located radially outward.

Note that a portion of the second opening 84b does not have to open to the inner surface of the second recess 85. For example, only the radially inner portion of the second opening 84b may open to the inner surface of the second recess 85, and the radially outer portion of the second opening 84b may be positioned radially outward from the second recess 85.

As shown in FIG. 5, at least a portion of the second recess 85 overlaps with the first surface 86a in the axial direction. Therefore, the portion of the end plate 80a that overlaps with the first surface 86a in the axial direction can be more easily elastically deformed in the axial direction. This makes it easier for the entire first surface 86a to come into contact with the rotor core 30. Therefore, the axial force applied from the end plate 80a to the rotor core 30 via the first surface 86a can be further improved. In this embodiment, the radially outer portion of the second recess 85 overlaps with the first surface 86a in the axial direction. The radially inner portion of the second recess 85 is located radially inner than the first surface 86a. The second recess 85 is provided for each of the multiple through holes 84.

The circumferential center of the through hole 84 is located on one circumferential side (+θ side) of the circumferential center of the core flow passage portion 35 connected to the through hole 84. In other words, the circumferential center of the through hole 84 is arranged to be shifted in the circumferential direction to the same side as the circumferential center of the third fitting portion 89 shifted from the first virtual line Ld with respect to the circumferential center of the core flow passage portion 35 provided in the third core piece part 37C and connected to the through hole 84. Therefore, a configuration can be adopted in which the circumferential center of the third fitting portion 89 is arranged at the same position in the circumferential direction as the circumferential center of any one of the through holes 84 while arranging the third fitting portion 89 to be shifted in the circumferential direction with respect to the first virtual line Ld. In this embodiment, the circumferential center of each third fitting portion 89 is located at the same position in the circumferential direction as the circumferential center of any one of the through holes 84.

Here, for example, in one end plate 80a, when the third fitting portion 89 is arranged to be shifted to the other circumferential side with respect to the through hole 84 and the through hole 84 and the core flow passage portion 35 are arranged to be centered in the circumferential direction, it is easy to increase the area where the through hole 84 of the end plate 80a and the core flow passage portion 35 overlap in the axial direction. However, in this case, if the end plates 80a and 80b are made to have the same shape, the third fitting portion 89 of the end plate 80b, which is arranged inverted in the axial direction, will be shifted to one circumferential side with respect to the through hole 84. Therefore, in the case where the circumferential positions of the core flow passage portion 35 in the core piece portion 37 where the end plates 80a and 80b contact are the same as in this embodiment, when the end plate 80b is arranged so that the circumferential position of the third fitting portion 89 is aligned with the end plate 80a, the through hole 84 in the end plate 80b will be shifted in the circumferential direction with respect to the core flow passage portion 35. Therefore, the through holes 84 in the end plate 80b may not be easily connected to the core flow passage portion 35. There is also a risk that the through holes 84 in the end plate 80b may overlap the magnet holes 50 in the axial direction. For example, if the shape of the end plate 80b is made different from the shape of the end plate 80a, it is possible to align the circumferential position of the through holes 84 in the end plate 80b with the circumferential position of the core flow passage portion 35 even if the end plate 80b is arranged axially inverted with respect to the end plate 80a. However, in that case, it is necessary to manufacture a pair of end plates 80a and 80b that are different in shape, which increases costs.

In contrast, in the present embodiment, the through holes 84 are shifted circumferentially relative to the core flow passage portion 35 and overlapped in the axial direction, so that the circumferential center of the third fitting portion 89 can be positioned at the same circumferential position as the circumferential center of any one of the through holes 84. If the circumferential center of the third fitting portion 89 is at the same circumferential position as the circumferential center of any one of the through holes 84, the relative positional relationship between the third fitting portion 89 and the through holes 84 in the circumferential direction does not change in the end plates 80a and 80b even if the end plates 80a and 80b are made to have the same shape and are inverted in the axial direction. Therefore, the relative position of the through holes 84 with respect to the core flow passage portion 35 can be made the same in both the end plates 80a and 80b, and it is possible to prevent the through holes 84 from being connected to the core flow passage portion 35 and from overlapping with the magnet holes 50 in the axial direction. In addition, because the end plates 80a and 80b can be formed to have the same shape, the cost of manufacturing the pair of end plates 80a and 80b can be prevented from increasing. In addition, because the circumferential center of the third fitting portion 89 can be arranged circumferentially offset from the first virtual line Ld, as described above, when multiple core piece portions 37 are arranged with a skew, the number of types of plate members 30a can be prevented from increasing.

As shown in FIG. 8, the end plate 80a has a third recess 88 provided on the first plate surface 86 and recessed in the axial direction. The third recess 88 is generally triangular in shape and protrudes radially outward when viewed in the axial direction. In this embodiment, the third recess 88 is provided on the radially inner portion of the first surface 86a and opens to the radially inner edge of the first surface 86a. As shown in FIG. 6, the third recess 88 overlaps with the crimped portion 30b in the axial direction. When viewed from the axial direction, the area of the third recess 88 is larger than the area of the crimped portion 30b. Therefore, even if the crimped portion 30b protrudes toward the end plate 80a, the end plate 80a can be prevented from coming into contact with the crimped portion 30b. This can prevent stress from concentrating on the crimped portion 30b.

As shown in FIG. 8, multiple third recesses 88 are provided at intervals in the circumferential direction. The multiple third recesses 88 are arranged at equal intervals around one circumference in the circumferential direction. The number of third recesses 88 is the same as the number of crimping portions 30b provided in one plate member 30a. In this embodiment, eight third recesses 88 are provided. Each third recess 88 is located between two through holes 84 adjacent to each other in the circumferential direction. The third recesses 88 do not necessarily have to be arranged at equal intervals, and may be arranged unequal. The number of third recesses 88 may be equal to or greater than the number of crimping portions 30b. One third recess 88 and multiple crimping portions 30b may be arranged to overlap in the axial direction.

As shown in FIG. 1, in this embodiment, the drive unit 100 is provided with a flow path 90 through which oil O flows as a refrigerant. In this embodiment, the flow path 90 is a flow path for supplying the oil O stored in the gear housing 63b to the rotor 10 and the stator 61. The flow path 90 is provided with a pump 96 and a cooler 97. The pump 96 is an electric pump. The flow path 90 has a first flow path portion 91, a second flow path portion 92, a third flow path portion 93, a fourth flow path portion 94, and a fifth flow path portion 95.

The first flow path section 91, the second flow path section 92, and the third flow path section 93 are provided, for example, in the wall section of the gear housing 63b. The first flow path section 91 connects the pump 96 to the part of the inside of the gear housing 63b where the oil O is stored. The second flow path section 92 connects the pump 96 to the cooler 97. The third flow path section 93 connects the cooler 97 to the fourth flow path section 94. In this embodiment, the third flow path section 93 is connected to an end on one axial side (+Y side) of the fourth flow path section 94, i.e., the upstream part of the fourth flow path section 94.

In this embodiment, the fourth flow path section 94 is tubular and extends in the axial direction. In other words, in this embodiment, the fourth flow path section 94 is a pipe that extends in the axial direction. Both axial ends of the fourth flow path section 94 are supported by the motor housing 63a. The end of one axial side (+Y side) of the fourth flow path section 94 is supported, for example, by the partition section 63d. The end of the other axial side (-Y side) of the fourth flow path section 94 is supported, for example, by the lid section 63e. The fourth flow path section 94 is located radially outside the stator 61. In this embodiment, the fourth flow path section 94 is located above the stator 61.

The fourth flow path section 94 has a supply port 94a that supplies oil O to the stator 61. In this embodiment, the supply port 94a is an injection port that injects a portion of the oil O that has flowed into the fourth flow path section 94 to the outside of the fourth flow path section 94. The supply port 94a is configured as a hole that penetrates the wall portion of the fourth flow path section 94 from the inner peripheral surface to the outer peripheral surface. Multiple supply ports 94a are provided in the fourth flow path section 94.

The fifth flow path section 95 connects the fourth flow path section 94 to the inside of the hollow shaft 20. More specifically, the fifth flow path section 95 connects the end of the fourth flow path section 94 on the other axial side (-Y side) to the end of the shaft 20 on the other axial side. In this embodiment, the fifth flow path section 95 is provided in the lid section 63e.

As shown in FIG. 1, when the pump 96 is driven, the oil O stored in the gear housing 63b is sucked up through the first flow path 91 and flows into the cooler 97 through the second flow path 92. The oil O that flows into the cooler 97 is cooled in the cooler 97, and then flows through the third flow path 93 to the fourth flow path 94. A portion of the oil O that flows into the fourth flow path 94 is sprayed from the supply port 94a and supplied to the stator 61. The other portion of the oil O that flows into the fourth flow path 94 flows into the first shaft hole 22a through the fifth flow path 95.

As shown in FIG. 4, the oil O flowing from the fifth flow passage 95 into the first shaft hole 22a flows in the first shaft hole 22a toward one axial side (toward the +Y side). A part of the oil O flowing inside the first shaft hole 22a flows into the plate flow passage 38a through the second shaft hole 22b. The oil O flowing into the plate flow passage 38a flows radially outward and branches into both axial sides at the radially outer end of the plate flow passage 38a. The branched oil O flows into each core flow passage 35 provided in each first core piece part 37A arranged on either side of the plate 38 in the axial direction. The oil O flowing into the core flow passage 35 provided in the first core piece part 37A flows axially outward in the core flow passage 35 provided in the second core piece part 37B and the core flow passage 35 provided in the third core piece part 37C in this order.

As shown in FIG. 9, the oil O flowing into the core flow passage portion 35 provided in the third core piece portion 37C flows axially outward and into the through hole 84 of the end plate 80. The oil O that flows into the through hole 84 is discharged from the second opening 84b to the outside of the rotor 10. As shown in FIG. 1, the oil O discharged to the outside of the rotor 10 is scattered radially outward from the axial end of the rotor core 30 toward the stator 61 due to the centrifugal force generated by the rotation of the rotor 10.

The other part of the oil O flowing inside the shaft 20 is discharged into the gear housing 63b and is stored again inside the gear housing 63b. The oil O supplied to the stator 61 from the supply port 94a and the core flow passage portion 35 falls downward and accumulates in the lower region inside the motor housing 63a. The oil O that has accumulated in the lower region inside the motor housing 63a returns to the gear housing 63b through the partition opening 63f provided in the partition portion 63d.

Below, embodiments different from the above-described embodiments are described. In the description of each embodiment below, the description of configurations similar to those described above in the description of each embodiment may be omitted by, for example, using the same reference numerals as appropriate. Furthermore, portions corresponding to the respective parts of the configurations described above in the description of each embodiment may be given the same names but different reference numerals to describe the differences from the above-described configurations, and the description of the similarities to the above-described configurations may be omitted. Note that, as the configurations whose description is omitted in each of the following embodiments, configurations similar to those described above in the description of each embodiment may be adopted within the scope of not being inconsistent.

Second Embodiment
As shown in FIG. 12, the end plate 280 in the rotor 210 of this embodiment does not have a protruding wall portion 82. In the end plate 280, the first recess 283 is recessed axially inward from the axially outer surface of the plate body portion 81, i.e., the second plate surface 87. The first recess 283 is provided in a portion of the small diameter portion 81b located radially outward from the through hole 84. Even when the first recess 283 is recessed in the axial direction as in this embodiment, by arranging at least a part of the first recess 283 at a position where it overlaps with the first surface 86a in the axial direction, it is possible to easily elastically deform the portion of the end plate 280 that overlaps with the first surface 86a in the axial direction. Therefore, it is possible to easily bring the first surface 86a into favorable contact with the rotor core 30, and the axial force applied from the end plate 280 to the rotor core 30 can be improved. In this embodiment, the entire first recess 283 overlaps with the first surface 86a in the axial direction. Note that FIG. 12 shows the end plate 280 in a state where it is not elastically deformed. Other configurations of the end plate 280 are similar to other configurations of the end plate 80 in the first embodiment. Other configurations of the rotor 210 are similar to other configurations of the rotor 10 in the first embodiment.

Third Embodiment
As shown in FIG. 13, in the end plate 380 of the rotor 310 of this embodiment, a plurality of first recesses 383 are provided at intervals in the circumferential direction. Each first recess 383 is recessed radially inward from the radially outer surface of the end plate 380. Each first recess 383 overlaps with the first surface 86a in the axial direction. As a result, as in the above-mentioned embodiment, the portion of the end plate 380 that overlaps with the first surface 86a in the axial direction can be easily elastically deformed in the axial direction, and the axial force applied from the end plate 380 to the rotor core 30 can be improved. The other configurations of the end plate 380 are the same as the other configurations of the end plate 80 in the first embodiment. The other configurations of the rotor 310 are the same as the other configurations of the rotor 10 in the first embodiment.

In this embodiment, the first recesses 383 are arranged at equal intervals in the circumferential direction. However, the intervals between the first recesses 383 do not necessarily have to be constant. The radial depth of each first recess 383 does not necessarily have to be constant and may be different from each other. The circumferential width of each first recess 383 does not necessarily have to be constant and may be different from each other. The cross-sectional area of each first recess 383 in a cross section perpendicular to the direction in which each first recess 383 is recessed does not necessarily have to be constant and may be different from each other. In this case, it is desirable to balance the entire end plate 380. In addition, the first recess 383 may be shaped to be recessed axially inward from the outer surface of the end plate 380. The first recess 383 may include both a recess that is recessed radially inward and a recess that is recessed axially inward. The axial positions of each first recess 383 do not necessarily have to be the same and may be shifted from each other.

Fourth Embodiment
As shown in FIG. 14, in the rotor core 430 of the rotor 410 of this embodiment, the magnet holding portion 431 has a pair of first magnet holes 51a, 51b and one second magnet hole 452. When viewed in the axial direction, the one second magnet hole 452 extends linearly in a direction perpendicular to the first virtual line Ld. When viewed in the axial direction, the second magnet hole 452 is disposed at a position overlapping the first virtual line Ld. The second magnet hole 452 has a shape that is line-symmetrical with the first virtual line Ld as the axis of symmetry. When viewed in the axial direction, the pair of first magnet holes 51a, 51b and the one second magnet hole 452 are disposed along a ∇ shape.

In this embodiment, in the magnet holding portion 431, a pair of first magnets 41a, 41b held in a pair of first magnet holes 51a, 51b, respectively, and a second magnet 442 held in a second magnet hole 452 are arranged along a ∇ shape when viewed in the axial direction. In this embodiment, the core flow path portion 435 has a shape that is line-symmetrical with respect to the first virtual line Ld as the axis of symmetry when viewed in the axial direction. In this embodiment, the core flow path portion 435 has an elliptical shape when viewed in the axial direction. The other configurations of the rotor 410 are similar to the other configurations of the rotor 10 in the first embodiment.

The present invention is not limited to the above-mentioned embodiment, and other configurations and methods may be adopted within the scope of the technical concept of the present invention. The contact surface of the end plate may have a surface other than the first surface. For example, in the above-mentioned first embodiment, when the axially inner end surface of the protrusion 86d contacts the rotor core 30, the end surface is included in the contact surface. The radially outer end of the first surface may be located on the first side (axially inner side) of the contact surface when the end plate is not elastically deformed, and may be located in any axial position relative to the portion other than the contact surface that does not contact the rotor core in the axial direction. In other words, the end plate may have a portion located on the first side (axially inner side) of the radially outer end of the first surface when the end plate is not elastically deformed, as long as it is not a contact surface that does not contact the rotor core in the axial direction. Specifically, the end plate may have a protrusion that protrudes to the first side from the first surface and is inserted into a hole provided in the rotor core.

The first surface may have any shape as long as it is located on the first side (axially inner side) as it moves radially outward when the end plate is not elastically deformed. The first surface does not have to be annular. A plurality of first surfaces may be provided at intervals in the circumferential direction. The first surface may be C-shaped when viewed in the axial direction. The radial position of the first surface is not particularly limited. The end plate does not necessarily have to be fixed by a washer and a nut. For example, the end plate may be fixed to the rotor core by other fixing means such as crimping or a bolt. The end plate may be composed of one member or multiple members. A pair of end plates may have the same shape or different shapes.

The first recess may be recessed in any direction as long as it is provided on the outer surface of the end plate. The first recess may be provided in any manner as long as at least a portion of the first recess overlaps with the first surface in the axial direction. A portion of the first recess may not overlap with the first surface in the axial direction. When a plurality of first recesses are provided, the plurality of first recesses may include first recesses recessed in different directions from each other. When the first recess is recessed in the radial direction, the cross-sectional area of the first recess in a cross section perpendicular to the radial direction may not be constant throughout the entire radial direction. For example, the cross-sectional area of the first recess in a cross section perpendicular to the radial direction may gradually increase from the radial inner side to the radial outer side. In other words, the cross-sectional area of the first recess in a cross section perpendicular to the radial direction is largest at the opening of the first recess. In addition, the axial dimension of the first recess may not be constant throughout the entire circumferential direction. In addition, when viewed from the radial direction, the shape of the opening of the first recess may be various shapes such as a substantially circular shape or a polygonal shape, and is not particularly limited. The end plate may have a combination of a first recess extending in the circumferential direction and a first recess extending in the axial direction.

The first plate surface may not have a convex portion. The first plate surface may not have a second surface. The second recess provided in the second plate surface may not overlap with the first surface in the axial direction. The second plate surface may not have a second recess. The first plate surface may not have a third recess. The through holes in the end plates that connect to the core flow path portion may be disposed in any manner relative to the core flow path portion. The end plates may not have through holes that connect to the core flow path portion. The protruding wall portions of the end plates may be portions used for any purpose.

The number of core piece parts is not particularly limited. The multiple core piece parts do not have to include core piece parts that are arranged offset in the circumferential direction. The number of magnets held in each core piece part is not particularly limited, as long as it is one or more. The arrangement of the magnets in each core piece part is not particularly limited.

The use of the drive unit to which the present invention is applied is not particularly limited. The drive unit may be mounted on a vehicle for a purpose other than rotating an axle, for example, or may be mounted on equipment other than a vehicle. The rotating electric machine to which the present invention is applied is not limited to a motor, and may be a generator. The use of the rotating electric machine is not particularly limited. The rotating electric machine may be mounted on equipment other than a vehicle. The attitude of the rotating electric machine when used is not particularly limited. The central axis of the rotating electric machine may extend in any direction.

The present technology can be configured as follows.
(1) A rotor rotatable about a central axis, comprising: a rotor core; and end plates having a first plate surface axially opposed to the rotor core and a second plate surface facing the opposite side to the first plate surface, wherein the first plate surface has a contact surface that axially contacts the rotor core when at least a portion of the end plate is elastically deformed in the axial direction, the contact surface having a first surface, wherein when the end plate is not elastically deformed, the first surface is located on a first side in the axial direction where the rotor core is positioned relative to the end plate as it moves radially outward, and when the end plate is not elastically deformed, a radially outer end of the first surface is a portion of the contact surface located furthest to the first side, and the end plate has a first recess provided on an outer surface of the end plate, and at least a portion of the first recess axially overlaps with the first surface.
(2) The rotor according to (1), further comprising a magnet held by the rotor core, wherein at least a portion of the first recess overlaps with the magnet in the axial direction.
(3) The rotor according to (1) or (2), wherein the first recess is annular and surrounds the central axis.
(4) The rotor according to any one of (1) to (3), wherein the first recess is recessed radially inward from a radially outer surface of the end plate.
(5) The rotor according to any one of (1) to (4), wherein the end plate has a plate body portion having the first plate surface and the second plate surface, and a protruding wall portion protruding in the axial direction from the second plate surface, the first recess is provided in the plate body portion, and at least a portion of the first recess overlaps with the protruding wall portion in the axial direction.
(6) The rotor according to (5), wherein the protruding wall portion and the first surface are located radially outward from a radial center between a radial inner edge portion of the end plate and a radial outer edge portion of the end plate.
(7) The rotor according to any one of (1) to (6), in which the radially outer end of the first surface is a radially outer end of the first plate surface.
(8) The rotor according to any one of (1) to (7), wherein the first plate surface has a second surface located radially inward of the first surface, and the second surface is located on a second side, in the axial direction, where the end plate is disposed with respect to the rotor core, relative to a radially inner end of the first surface.
(9) The rotor according to (8), wherein the end plate has a protrusion provided on the first plate surface and protruding in the axial direction, the protrusion being located radially inward from the second surface.
(10) The rotor according to (9), wherein the protrusion is located on the second side relative to a radially inner end of the first surface when the end plate is not elastically deformed.
(11) The rotor core has a core flow passage portion extending in an axial direction, and the end plates have through holes that penetrate the end plates in the axial direction and are connected to the core flow passage portion in the axial direction,
The rotor according to any one of (1) to (10), wherein the through hole has a first opening that opens to the first surface.
(12) The rotor according to (11), wherein the end plate has a second recess provided in the second plate surface and recessed in the axial direction, the through hole has a second opening that opens into the second plate surface, and at least a portion of the second opening opens to an inner surface of the second recess.
(13) The rotor according to (12), wherein at least a portion of the second recess overlaps with the first surface in the axial direction.
(14) The rotor according to any one of (11) to (13), comprising: a shaft extending in the axial direction and to which the rotor core is fixed, the rotor core having the core flow passage portion and a core piece portion in axial contact with the end plate, the shaft having a first fitting portion recessed in the radial direction or protruding in the radial direction, the core piece portion having a second fitting portion fitted with the first fitting portion and a plurality of magnetic pole portions arranged side by side in the circumferential direction, the end plate having a third fitting portion fitted with the first fitting portion, a circumferential center of the first fitting portion, a circumferential center of the second fitting portion, and a circumferential center of the third fitting portion are disposed circumferentially offset with respect to an imaginary line that passes through the circumferential center of the magnetic pole portions and extends in the radial direction, and a circumferential center of the through hole is disposed circumferentially offset with respect to a circumferential center of the core flow passage portion provided in the core piece portion and connected to the through hole, on the same side as a side on which the circumferential center of the third fitting portion is offset with respect to the imaginary line.
(15) The rotor according to any one of (1) to (14), wherein the rotor core has a plurality of plate members stacked in the axial direction, and adjacent plate members in the axial direction are fixed to each other by a crimped portion formed by crimping a part of the plate member in the axial direction, and the end plate has a third recess provided on the first plate surface and recessed in the axial direction, the third recess overlaps with the crimped portion in the axial direction, and an area of the third recess is larger than an area of the crimped portion as viewed in the axial direction.
(16) A rotating electric machine comprising: a rotor according to any one of (1) to (15); and a stator facing the rotor with a gap therebetween.
(17) A drive device comprising: the rotating electric machine according to (16); and a gear mechanism connected to the rotating electric machine.

The configurations and methods described in this specification can be combined as appropriate within the limits of not being mutually inconsistent.

10, 210, 310, 410...rotor, 10N, 10P, 10S...magnetic pole portion, 20...shaft, 21...first fitting portion, 30, 430...rotor core, 30a...plate member, 30b...crimping portion, 32...second fitting portion, 35, 435...core flow passage portion, 37C...third core piece portion (core piece portion), 40...magnet, 60...rotating electric machine, 61...stator, 70...gear mechanism, 80, 80a, 80b, 280, 380 ...end plate, 81...plate body, 82...protruding wall, 83, 283, 383...first recess, 84...through hole, 84a...first opening, 84b...second opening, 85...second recess, 86...first plate surface, 86a...first surface, 86b...second surface, 86d...projection, 86e...contact surface, 87...second plate surface, 88...third recess, 89...third fitting portion, 100...driver, J...center axis, Ld...first virtual line (virtual line)

Claims (17)

A rotor rotatable about a central axis,
A rotor core;
an end plate having a first plate surface that faces the rotor core in the axial direction and a second plate surface that faces an opposite side to the first plate surface;
Equipped with
the first plate surface has a contact surface that is in axial contact with the rotor core in a state in which at least a portion of the end plate is elastically deformed in the axial direction,
The contact surface has a first surface,
When the end plate is not elastically deformed, the first surface is located on a first side in the axial direction where the rotor core is disposed with respect to the end plate as the first surface moves radially outward,
When the end plate is not elastically deformed, a radially outer end portion of the first surface is a portion of the contact surface located closest to the first side,
the end plate has a first recess provided in an outer surface of the end plate;
At least a portion of the first recess axially overlaps with the first surface. A magnet is provided to the rotor core,
The rotor according to claim 1 , wherein at least a portion of the first recess overlaps with the magnet in the axial direction. The rotor of claim 1, wherein the first recess is annular and surrounds the central axis. The rotor of claim 1, wherein the first recess is recessed radially inward from the radially outer surface of the end plate. The end plate is
a plate body portion having the first plate surface and the second plate surface;
a protruding wall portion protruding in an axial direction from the second plate surface;
having
The first recess is provided in the plate body,
The rotor according to claim 1 , wherein at least a portion of the first recess axially overlaps with the protruding wall portion. The rotor of claim 5, wherein the protruding wall portion and the first surface are located radially outward of the radial center between the radial inner edge portion of the end plate and the radial outer edge portion of the end plate. The rotor of claim 1, wherein the radially outer end of the first surface is the radially outer end of the first plate surface. The first plate surface has a second surface located radially inward of the first surface,
The rotor according to claim 1 , wherein the second surface is located on a second side in the axial direction, where the end plate is disposed with respect to the rotor core, relative to a radially inner end of the first surface. the end plate has a protrusion provided on the first plate surface and protruding in an axial direction,
The rotor according to claim 8 , wherein the protrusion is located radially inward from the second surface. The rotor according to claim 9, wherein when the end plate is not elastically deformed, the protrusion is located on the second side relative to the radially inner end of the first surface. The rotor core has a core flow passage portion extending in an axial direction,
the end plate has a through hole that penetrates the end plate in the axial direction and is connected to the core flow path portion in the axial direction,
The rotor according to claim 1 , wherein the through hole has a first opening that opens to the first surface. the end plate has a second recess provided in the second plate surface and recessed in the axial direction,
the through hole has a second opening that opens into the second plate surface,
The rotor according to claim 11 , wherein at least a portion of the second opening is open to an inner surface of the second recess. The rotor of claim 12, wherein at least a portion of the second recess overlaps with the first surface in the axial direction. a shaft extending in an axial direction and to which the rotor core is fixed;
the rotor core has a core piece portion having the core flow passage portion and contacting the end plate in the axial direction,
The shaft has a first fitting portion that is recessed in a radial direction or protrudes in a radial direction,
The core piece portion is
a second fitting portion that is fitted into the first fitting portion;
A plurality of magnetic pole portions arranged side by side in a circumferential direction;
having
the end plate has a third fitting portion that is fitted into the first fitting portion,
a circumferential center of the first fitting portion, a circumferential center of the second fitting portion, and a circumferential center of the third fitting portion are disposed so as to be shifted in the circumferential direction with respect to a virtual line passing through a circumferential center of the magnetic pole portion and extending in a radial direction;
12. The rotor according to claim 11, wherein a circumferential center of the through hole is shifted in the circumferential direction to the same side as a circumferential center of the third fitting portion is shifted from the virtual line relative to a circumferential center of the core flow passage portion provided in the core piece portion and connected to the through hole. The rotor core has a plurality of plate members stacked in the axial direction,
The plate members adjacent to each other in the axial direction are fixed to each other by crimping portions formed by crimping parts of the plate members in the axial direction,
the end plate has a third recess provided on the first plate surface and recessed in the axial direction;
The third recess overlaps with the crimped portion in the axial direction,
The rotor according to claim 1 , wherein an area of the third recess is larger than an area of the crimped portion when viewed in the axial direction. A rotor according to any one of claims 1 to 15;
a stator facing the rotor with a gap therebetween;
A rotating electric machine comprising: A rotating electric machine according to claim 16;
a gear mechanism connected to the rotating electric machine;
A drive device comprising:

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