Rotor, rotating electrical machine, and drive device

Abstract

The rotor has a shaft and a rotor core. The rotor core has: a through-hole through which the shaft passes in the axial direction; a protruding portion provided on a radial inner edge portion of the through hole; and a plurality of recesses provided at intervals in the circumferential direction on the inner edge of the through-hole in the radial direction. When a plurality of imaginary lines are defined, one of the plurality of imaginary lines overlaps the center of the projection in the circumferential direction when viewed in the axial direction, and the plurality of imaginary lines extend radially outward from the central axis when viewed in the axial direction. The number of the protrusions and the number of the recesses are the same as the sum of the number of the protrusions and the number of the recesses. The plurality of recesses include: a first recess; and a second recess that overlaps the imaginary line when viewed in the axial direction. The first recess satisfies at least one of the following conditions: when viewed in the axial direction, the circumferential arrangement relationship with respect to an imaginary line closest to the first recess in the circumferential direction differs from the circumferential arrangement relationship with respect to an imaginary line overlapping the second recess; the second recess has a shape different from that of the second recess when viewed in the axial direction. The second recess has a circumferential dimension different from that of the second recess when viewed in the axial direction.

Description

Technical Field

[0001] The invention relates to a rotor, a rotating electrical machine and a driving device.

[0002] This application claims priority based on Japanese Patent Application No. 2022-191774 filed in Japan on November 30, 2022, the contents of which are cited here. Background Art

[0003] There is known a shaft body with an iron core portion for a rotating electric machine having an iron core portion having a convex portion corresponding to a key groove provided on the shaft body. For example, Patent Document 1 describes an iron core portion having a pair of convex portions sandwiching a shaft body.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-81953 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the shaft body with an iron core portion used in the rotating electric machine as described above, a pair of keyways need to be provided on the shaft body, so the manufacturing cost of the shaft body may increase. In contrast, if a structure is adopted in which one keyway and one convex portion are provided, the increase in the manufacturing cost of the shaft body can be suppressed. However, in this case, due to the provision of the keyway and the convex portion, the circumferential weight balance of the shaft body with the iron core portion may be destroyed, resulting in the center of gravity of the shaft body with the iron core portion being offset relative to the rotation center of the shaft body with the iron core portion. Therefore, in the rotating electric machine, when the shaft body with the iron core portion rotates, the vibration of the shaft body with the iron core portion becomes larger, and noise may be generated.

[0009] In view of the above circumstances, one object of the present invention is to provide a rotor having a structure capable of suppressing the deviation of the center of gravity with respect to the central axis, and a rotating electric machine and a drive device having such a rotor.

[0010] Means for solving problems

[0011] One embodiment of the present invention is a rotor that can rotate around a central axis, wherein the rotor has: a shaft that extends in the axial direction; and a rotor core that is fixed to the shaft. The rotor core has: a through hole for the shaft to pass through in the axial direction; a protrusion that is provided at the radial inner edge of the through hole and protrudes radially inward; and a plurality of recesses that are provided at intervals in the circumferential direction at the radial inner edge of the through hole and are recessed radially outward. When a plurality of imaginary lines are specified, one of the plurality of imaginary lines overlaps with the circumferential center of the protrusion when viewed in the axial direction, and the plurality of imaginary lines extend from the central axis to the radial outer side when viewed in the axial direction, are arranged at equal intervals in the circumferential direction, and the number of the imaginary lines is the same as the total number of the protrusions and the recesses when viewed in the axial direction. The plurality of recesses include: a first recess; and a second recess that overlaps with the imaginary line when viewed in the axial direction. The first recess satisfies at least one of the following conditions: when viewed axially, the circumferential configuration relationship relative to the imaginary line closest to the first recess in the circumferential direction is different from the circumferential configuration relationship of the second recess relative to the imaginary line overlapping with the second recess; when viewed axially, it has a shape different from that of the second recess; and when viewed axially, it has a circumferential size different from that of the second recess.

[0012] A rotating electrical machine according to one aspect of the present invention includes: the above-mentioned rotor; and a stator facing the rotor with a gap therebetween in a radial direction.

[0013] A driving device according to one aspect of the present invention includes: the above-mentioned rotating electric machine; and a gear mechanism connected to the rotating electric machine.

[0014] Effects of the Invention

[0015] According to one aspect of the present invention, in a rotating electrical machine and a drive device, it is possible to suppress the center of gravity of a rotor from shifting relative to the central axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a diagram schematically showing the driving device in the first embodiment.

[0017] Figure 2 It is a cross-sectional view showing the rotor in the first embodiment.

[0018] Figure 3 It is a cross-sectional view showing a part of the rotor core in the first embodiment.

[0019] Figure 4 It is a cross-sectional view showing the stacked body in the first embodiment.

[0020] Figure 5It is a cross-sectional view showing a part of the rotor core in the second embodiment.

[0021] Figure 6 It is a cross-sectional view showing a part of the rotor core in the third embodiment. DETAILED DESCRIPTION

[0022] In the following description, the vertical direction is defined and described based on the positional relationship when the drive device of the embodiment is mounted on a vehicle located on a horizontal road surface. That is, the relative positional relationship related to the vertical direction described in the following embodiments only needs to be satisfied at least when the drive device is mounted on a vehicle located on a horizontal road surface.

[0023] In the accompanying drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is the vertical direction. The +Z side is the upper side in the vertical direction, and the -Z side is the lower side in the vertical direction. In the following description, the upper side in the vertical direction is referred to as the "upper side", and the lower side in the vertical direction is referred to as the "lower side". The X-axis direction is a direction perpendicular to the Z-axis direction, and is the front-to-back direction of a vehicle equipped with a drive device. In the following embodiments, the +X side is the front side of the vehicle, and the -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-to-right direction of the vehicle, that is, the vehicle width direction. In the following embodiments, the +Y side is the left side of the vehicle, and the -Y side is the right side of the vehicle. The front-to-back direction and the left-to-right direction are horizontal directions perpendicular to the vertical direction.

[0024] In addition, the positional relationship in the front-rear direction is not limited to the positional relationship in the following embodiments, 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 addition, in this specification, "parallel direction" also includes a substantially parallel direction, and "vertical direction" also includes a substantially vertical direction.

[0025] The center axis J shown in the figure appropriately is an imaginary axis extending in a direction intersecting the vertical direction. In more detail, the center axis J extends in the Y-axis direction perpendicular to the vertical direction, that is, the left-right direction of the vehicle. In the following description, unless otherwise specified, the direction parallel to the center axis J is referred to as the "axial direction", the radial direction centered on the center axis J is referred to as the "radial direction", and the circumferential direction centered on the center axis J, that is, the direction around the center axis J is referred to as the "circumferential direction". In the following embodiments, the left side (+Y side) is referred to as the "one axial side", and the right side (-Y side) is referred to as the "other axial side".

[0026] The arrow θ shown in the figure appropriately indicates the circumferential direction. In the following description, the side that moves clockwise around the central axis J when viewed from the right side (-Y side) in the circumferential direction, that is, the side toward which the arrow θ points (+θ side) is referred to as "one side in the circumferential direction", and the side that moves counterclockwise around the central axis J when viewed from the right side in the circumferential direction, that is, the side opposite to the side toward which the arrow θ points (-θ side) is referred to as "the other side in the circumferential direction".

[0027] <First embodiment>

[0028] Figure 1 The drive device 100 of the present embodiment shown is a drive device mounted on a vehicle and rotates the axle 73. The vehicle equipped with the drive device 100 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). Figure 1 As shown, the drive device 100 includes a rotary electric machine 60, a gear mechanism 70 connected to the rotary electric machine 60, and a housing 63 that accommodates the rotary electric machine 60 and the gear mechanism 70. In the present embodiment, the rotary electric machine 60 is a motor.

[0029] The housing 63 accommodates the rotating motor 60 and the gear mechanism 70 therein. The housing 63 includes: a motor housing 63a that accommodates the rotating motor 60 therein; and a gear housing 63b that accommodates 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 includes a peripheral wall portion 63c, a partition wall portion 63d, and a cover portion 63e. The peripheral wall portion 63c and the partition wall portion 63d are, for example, parts of the same single component. The cover portion 63e is, for example, separate from the peripheral wall portion 63c and the partition wall portion 63d.

[0030] The peripheral wall portion 63c is in the shape of a tube that surrounds the central axis J and opens on the other axial side (-Y side). The partition wall portion 63d is connected to the end of the peripheral wall portion 63c on one axial side (+Y side). The partition wall portion 63d separates the interior of the motor housing 63a from the interior of the gear housing 63b in the axial direction. The partition wall portion 63d has a partition wall opening 63f that connects the interior of the motor housing 63a and the interior of the gear housing 63b. A bearing 64a is retained in the partition wall portion 63d. The cover portion 63e is fixed to the end of the peripheral wall portion 63c on the other axial side. The cover portion 63e closes the opening on the other axial side of the peripheral wall portion 63c. A bearing 64b is retained in the cover portion 63e.

[0031] The gear housing 63b contains oil O inside. The oil O is stored in the lower area of ​​the gear housing 63b. The oil O circulates in the flow path 90 described later. The oil O is used as a refrigerant for cooling the rotary electric machine 60. In addition, the oil O is used as a lubricating oil in the gear mechanism 70. As the oil O, for example, in order to exert the functions of a refrigerant and a lubricating oil, it is preferable to use an oil equivalent to an automatic transmission lubricating oil (ATF: Automatic Transmission Fluid) having a relatively low viscosity.

[0032] The gear mechanism 70 is connected to the rotary motor 60, and transmits the rotation of the rotor 10 described later to the axle 73 of the vehicle. The gear mechanism 70 of the present embodiment has a reduction gear 71 connected to the rotary motor 60 and a differential device 72 connected to the reduction gear 71. The differential device 72 has a ring gear 72a. The torque output from the rotary motor 60 is transmitted to the ring gear 72a via the reduction gear 71. The lower end of the ring gear 72a is immersed in the oil O stored in the gear housing 63b. The oil O is lifted up by the rotation of the ring gear 72a. The lifted oil O is provided to the reduction gear 71 and the differential device 72 as lubricating oil, for example.

[0033] The rotating electric machine 60 includes: a rotor 10, which can rotate around a central axis J; and a stator 61, which is opposite to the rotor 10 in the radial direction with a gap therebetween. In the present embodiment, the stator 61 is located radially outside the rotor 10. The stator 61 includes: a stator core 61a; and a coil assembly 61b, which is mounted on the stator core 61a. The coil assembly 61b includes a plurality of coils 61c mounted on the stator core 61a. Although not shown in the figure, the coil assembly 61b may include a bundling member for bundling the coils 61c, or may include a lap wire connecting the coils 61c to each other. The coil assembly 61b includes coil ends 61d and 61e that protrude axially from the stator core 61a.

[0034] like Figure 2 As shown, the rotor 10 has a shaft 20, a rotor core 30, and a plurality of magnets 40. Figure 1 As shown in FIG. 1 , the shaft 20 extends axially with the central axis J as the center. The end of the shaft 20 on one axial side (+Y side) protrudes into the gear housing 63b. Figure 2 As shown in the figure, in this embodiment, the shaft 20 is a cylindrical hollow shaft centered on the central axis J. The shaft 20 has a groove 21 that is recessed radially inward from the outer circumference of the shaft 20. Although not shown in the figure, the groove 21 extends in the axial direction. In this embodiment, only one groove 21 is provided. Figure 1 As shown, the shaft 20 is provided with a hole portion 22 that connects the inside of the shaft 20 and the outside of the shaft 20. A plurality of the hole portions 22 are provided at intervals in the circumferential direction.

[0035] like Figure 2 As shown, the rotor core 30 is fixed to the outer peripheral surface of the shaft 20. The rotor core 30 is substantially cylindrical with the center axis J as the center. The rotor core 30 has a through hole 30h that passes through the rotor core 30 in the axial direction. The center axis J passes through the inside of the through hole 30h. In the present embodiment, the through hole 30h is a substantially circular hole with the center axis J as the center. The shaft 20 passes through the through hole 30h in the axial direction. The inner peripheral surface of the through hole 30h is fixed to the outer peripheral surface of the shaft 20. The shaft 20 is, for example, press-fitted into the through hole 30h.

[0036] The radial inner side surface of the through hole 30h has a support surface 30i. The support surface 30i is a surface extending in an arc shape with the central axis J as the center when viewed in the axial direction. A plurality of support surfaces 30i are provided at intervals in the circumferential direction. In the present embodiment, four support surfaces 30i are provided. When viewed in the axial direction, the plurality of support surfaces 30i are arranged on the same circle with the central axis J as the center. The plurality of support surfaces 30i are in contact with the outer peripheral surface of the shaft 20.

[0037] The rotor core 30 is made of a magnetic system. Figure 1 As shown, the rotor core 30 has a plurality of plate members 30a stacked in the axial direction. The plate member 30a is a plate-shaped member with the plate surface facing the axial direction. The plate member 30a is in a substantially circular plate shape centered on the central axis J. The material of the plate member 30a is a rolled steel material produced by rolling in a predetermined direction. The material of the plate member 30a is, for example, an electromagnetic steel sheet.

[0038] The plate components 30a are stacked in a state where each one or more plate components 30a are rotated in the circumferential direction at a predetermined angle. That is, in the present embodiment, a plurality of plate components 30a are rotationally stacked. In the present embodiment, the predetermined angle at which the plate components 30a are rotationally stacked is 90°. In this way, the plurality of plate components 30a are rotationally stacked, and thus the plurality of plate components 30a include two or more plate components 30a whose rolling directions are different from each other. The rolling direction of the plate component 30a is the direction in which the rolled steel material that is the material of the plate component 30a is rolled.

[0039] Although not shown in the figure, the rotor core 30 has a plurality of core pieces arranged in the axial direction. Each core piece is formed by stacking a plurality of plate members 30a in the axial direction. Although not shown in the figure, a substantially disk-shaped plate is provided between at least one set of core pieces adjacent to each other in the axial direction.

[0040] like Figure 2 As shown, the rotor core 30 has a plurality of magnet retaining portions 31 arranged in a circumferential direction. The plurality of magnet retaining portions 31 are provided in the radially outer portion of the rotor core 30. The plurality of magnet retaining portions 31 are arranged at equal intervals throughout the entire circumference along the circumferential direction. In this embodiment, eight magnet retaining portions 31 are provided.

[0041] The plurality of magnet holding portions 31 have a pair of first magnet holes 51a, 51b adjacent to each other in the circumferential direction. That is, the rotor core 30 has a pair of first magnet holes 51a, 51b. Thus, in the present embodiment, each magnet holding portion 31 is provided with a pair of first magnet holes 51a, 51b, which are the two magnet holes in total. In the present embodiment, the pair of first magnet holes 51a, 51b penetrates the rotor core 30 in the axial direction. In addition, the pair of first magnet holes 51a, 51b may also be holes having a bottom at the end in the axial direction.

[0042] A magnet 40 is disposed in each of the two magnet holes in each magnet holding portion 31. The type of the magnet 40 is not particularly limited. The magnet 40 may be, for example, a neodymium magnet or a ferrite magnet. The magnet 40 may be, for example, a rectangular parallelepiped that is long in the axial direction. The magnet 40 may extend from one axial end portion of the rotor core 30 to the other axial end portion.

[0043] The plurality of magnets 40 include a pair of first magnets 41a, 41b respectively arranged in a pair of first magnet holes 51a, 51b. Each magnet 40 is fixed in each magnet hole. There is no particular limitation on the method of fixing each magnet 40 in each magnet hole. For example, each magnet can be fixed in each magnet hole by caulking a portion of the rotor core 30, can be fixed in each magnet hole by filling a resin in a portion other than the portion where the magnet 40 is arranged in each magnet hole, or can be fixed in each magnet hole by a foam sheet arranged in a portion other than the portion where the magnet 40 is arranged in each magnet hole.

[0044] The magnetic pole portion 10P is composed of a magnet holding portion 31 and a plurality of magnets 40 arranged in a plurality of magnet holes provided in the magnet holding portion 31. A plurality of magnetic pole portions 10P are arranged at equal intervals along the circumferential direction throughout the entire circumference. That is, the rotor 10 has a plurality of magnetic pole portions 10P arranged at intervals along the circumferential direction. In the present embodiment, eight magnetic pole portions 10P are provided. The plurality of magnetic pole portions 10P include a plurality of magnetic pole portions 10N whose magnetic poles on the outer circumferential surface of the rotor core 30 are N poles and a plurality of magnetic pole portions 10S whose magnetic poles on the outer circumferential surface of the rotor core 30 are S poles. In the present embodiment, four magnetic pole portions 10N and four magnetic pole portions 10S are provided. The four magnetic pole portions 10N and the four magnetic pole portions 10S are alternately arranged along the circumferential direction. The structure of each magnetic pole portion 10P is the same except that the magnetic poles on the outer circumferential surface of the rotor core 30 are different and the circumferential positions are different.

[0045] In the magnetic pole portion 10P, the first magnet hole 51a and the first magnet hole 51b are arranged circumferentially with the magnetic pole center line Ld between them. The magnetic pole center line Ld is an imaginary line that passes through the circumferential center between a pair of first magnet holes 51a and 51b and extends radially. The magnetic pole center line Ld 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 retaining portion 31. The magnetic pole center line Ld is provided for each magnetic pole portion 10P. When viewed in the axial direction, the magnetic pole center line Ld passes on the d-axis of the rotor 10. The direction in which the magnetic pole center 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 line-symmetrically with the magnetic pole center line Ld as the axis of symmetry.

[0046] When viewed in the axial direction, the pair of first magnet holes 51a, 51b extend in a direction that separates from each other in the circumferential direction from the radial inside to the radial outside. That is, the circumferential distance between the first magnet hole 51a and the first magnet hole 51b increases from the radial inside to the radial outside. When viewed in the axial direction, the pair of first magnet holes 51a, 51b are arranged in a V-shape that expands in the circumferential direction as they go toward the radial outside. When viewed in the axial direction, the pair of first magnets 41a, 41b arranged in the pair of first magnet holes 51a, 51b are arranged in a V-shape that expands in the circumferential direction as they go toward the radial outside.

[0047] like Figure 3 As shown, the rotor core 30 has a protrusion 32 provided at the radial inner edge of the through hole 30h. The protrusion 32 protrudes radially inward. The radial inner end of the protrusion 32 is located at a position radially inward of the support surface 30i. Although not shown in the figure, the protrusion 32 extends in the axial direction. In the present embodiment, only one protrusion 32 is provided at the radial inner edge of the through hole 30h. When viewed in the axial direction, the protrusion 32 is roughly rectangular. The radial inner surface of the protrusion 32 is perpendicular to the radial direction. When viewed in the axial direction, the protrusion 32 is arranged at a position overlapping with the magnetic pole center line Ld that passes through the circumferential center of the magnetic pole portion 10P and extends in the radial direction. Therefore, the strength of the radial inner portion of the magnet 40 in the magnetic pole portion 10P in the rotor core 30 can be improved by the protrusion 32. As a result, it is easy to more stably hold the magnet 40 in the magnetic pole portion 10P. In the present embodiment, when viewed in the axial direction, the center of the protrusion 32 in the circumferential direction overlaps with the magnetic pole center line Ld in one magnetic pole portion 10P.

[0048] like Figure 2 As shown, the protrusion 32 is fitted into the groove 21. Thus, the shaft 20 and the rotor core 30 are hooked with each other in the circumferential direction, and the shaft 20 and the rotor core 30 can be prevented from rotating relative to each other in the circumferential direction.

[0049] like Figure 3As shown, recessed portions 34 are respectively provided on both sides of the protrusion 32 in the circumferential direction. A pair of recessed portions 34 are provided at the radial inner edge of the through hole 30h and are recessed radially outward. A pair of recessed portions 34 are recessed radially outward from the support surface 30i. In this embodiment, when viewed in the axial direction, the inner edges of the pair of recessed portions 34 are curved in a direction protruding radially outward. A pair of recessed portions 34 are arranged adjacent to the protrusion 32 in the circumferential direction across the protrusion 32.

[0050] By providing a pair of recessed portions 34 as described above, a part of the stress generated by the shaft 20 when the shaft 20 is pressed into the through hole 30h can be released at the portion of the shaft 20 that is radially opposite to the pair of recessed portions 34. Therefore, the shaft 20 can be easily pressed into the through hole 30h. In addition, by arranging a pair of recessed portions 34 adjacent to each other on both sides of the protrusion 32 in the circumferential direction, the inner edge portion of the through hole 30h connected to the radially outer end of the protrusion 32 can be the inner edge of the recessed portion 34. Thus, by making the shape of the inner edge of the recessed portion 34 when viewed in the axial direction a curved shape, it is easy to smoothly connect the radially outer end of the protrusion 32 to the inner edge of the through hole 30h. Therefore, it is easy to dispersely bear the stress generated by the protrusion 32 at the connection portion between the radially outer end of the protrusion 32 and the inner edge of the recessed portion 34.

[0051] The rotor core 30 has a plurality of recesses 80 arranged at intervals in the circumferential direction at the radial inner edge of the through hole 30h. The plurality of recesses 80 are recessed radially outward. In the present embodiment, the plurality of recesses 80 are recessed radially outward from the support surface 30i. In the present embodiment, the support surface 30i is respectively arranged between the recesses 80 adjacent to each other in the circumferential direction and between the recesses 80 and the recessed portion 34 in the circumferential direction at the radial inner edge of the through hole 30h. The plurality of recesses 80 are arranged, for example, throughout the entire axial direction of the rotor core 30. In addition, the plurality of recesses 80 may also be arranged only in a portion of the axial direction of the rotor core 30.

[0052] When viewed in the axial direction, the plurality of recesses 80 are substantially arc-shaped and extend in the circumferential direction. In the present embodiment, when viewed in the axial direction, the plurality of recesses 80 are of the same shape as each other. Therefore, for example, when the recesses 80 are produced by cutting off a portion of the laminated body 130 described later by a mold or the like, the plurality of recesses 80 can be produced by one mold. Thus, it is not necessary to prepare a plurality of molds in order to produce the plurality of recesses 80, and the manufacturing cost of the rotor 10 can be reduced.

[0053] In addition, in this specification, regarding "the shapes of two recesses are the same when viewed in the axial direction", as long as the shapes of the two recesses are the same when viewed in the axial direction, the sizes of the two recesses when viewed in the axial direction may be different. Regarding "the size of the recess when viewed in the axial direction", it refers to the area of ​​the interior of the recess in the cross section perpendicular to the axial direction. "The area of ​​the interior of the recess in the cross section perpendicular to the axial direction" refers to the area of ​​the region surrounded by the outer peripheral surface of the shaft and the inner edge of the recess in the cross section perpendicular to the axial direction. In the present embodiment, when viewed in the axial direction, the sizes of the plurality of recesses 80 are the same. In other words, the area of ​​the region surrounded by the outer peripheral surface of the shaft 20 and the inner edge of each recess 80 in the cross section perpendicular to the axial direction is the same.

[0054] The plurality of recesses 80 include a first recess 81 and a second recess 82. In the present embodiment, the recess 80 is provided with two first recesses 81 and one second recess 82, which are a total of three recesses. The two first recesses 81 include a first recess 81a and a first recess 81b. The two first recesses 81a and 81b are arranged with one second recess 82 in the circumferential direction. The second recess 82 is located on the opposite side of the protrusion 32 across the center axis J in the radial direction. That is, the plurality of recesses 80 include a recess 80 that is arranged on the opposite side of the protrusion 32 across the center axis J in the radial direction, and the recess 80 is the second recess 82.

[0055] In the present embodiment, a plurality of imaginary lines S1 are provided, which extend radially outward from the central axis J when viewed in the axial direction, are arranged at equal intervals in the circumferential direction, and are the same in number as the sum of the number of protrusions 32 and the number of recesses 80. In the present embodiment, the number of protrusions 32 is one, and the number of recesses 80 is three. The sum of the number of protrusions 32 and the number of recesses 80 is four. Therefore, in the present embodiment, the imaginary lines S1 are provided with a total of four imaginary lines, namely, an imaginary line S1a, an imaginary line S1b, an imaginary line S1c, and an imaginary line S1d. The four imaginary lines S1a, S1b, S1c, and S1d are arranged at equal intervals at intervals of 90° in the circumferential direction. The imaginary line S1a is an imaginary line S1 that overlaps with the center of the circumferential direction of the protrusion 32 when viewed in the axial direction. In the present embodiment, when viewed in the axial direction, the imaginary line S1 a is arranged at a position overlapping with the magnetic pole center line Ld, and the magnetic pole center line Ld overlaps with the protrusion 32 .

[0056] The imaginary line S1b is arranged adjacent to the imaginary line S1a at intervals of 90° on one circumferential side (+θ side). The imaginary line S1c is arranged adjacent to the imaginary line S1b at intervals of 90° on one circumferential side. The imaginary line S1d is arranged adjacent to the imaginary line S1c at intervals of 90° on one circumferential side. When viewed in the axial direction, the imaginary line S1a and the imaginary line S1c are arranged on the same straight line. When viewed in the axial direction, the imaginary line S1b and the imaginary line S1d are arranged on the same straight line. The imaginary lines S1a, S1c and the imaginary lines S1b, S1d extend in directions perpendicular to each other. When viewed in the axial direction, the imaginary lines S1b, S1c, S1d are also arranged at positions overlapping with the magnetic pole center lines Ld in different magnetic pole portions 10P.

[0057] In the present embodiment, when viewed in the axial direction, each of the imaginary lines S1b, S1c, and S1d overlaps with the plurality of recesses 80, respectively. When viewed in the axial direction, the imaginary line S1b overlaps with the first recess 81a. When viewed in the axial direction, the imaginary line S1c overlaps with the second recess 82. When viewed in the axial direction, the imaginary line S1d overlaps with the first recess 81b. That is, when viewed in the axial direction, the first recess 81 and the second recess 82 overlap with the imaginary line S1, respectively. The imaginary line S1 closest to the first recess 81a in the circumferential direction is the imaginary line S1b. The imaginary line S1 closest to the first recess 81b in the circumferential direction is the imaginary line S1d. The imaginary line S1 closest to the second recess 82 in the circumferential direction is the imaginary line S1c.

[0058] When viewed in the axial direction, the second recessed portion 82 extends in the circumferential direction. When viewed in the axial direction, the inner edge of the second recessed portion 82 is curved in a direction convex to the radial outside. When viewed in the axial direction, the center of the circumferential direction of the second recessed portion 82 overlaps with the imaginary line S1c. When viewed in the axial direction, the second recessed portion 82 is linearly symmetrical with the imaginary line S1c passing through the second recessed portion 82 as the axis of symmetry.

[0059] When viewed in the axial direction, the first recesses 81a and 81b extend in the circumferential direction. When viewed in the axial direction, the inner edges of the first recesses 81a and 81b are curved in a direction protruding radially outward. When viewed in the axial direction, the shapes of the first recesses 81a and 81b are the same as the shapes of the second recesses 82. When viewed in the axial direction, the circumferential dimension L1 of the first recesses 81a and 81b is the same as the circumferential dimension L2 of the second recess 82. Each dimension L1 and L2 is greater than the circumferential dimension L3 of the portion including the protrusion 32 and the pair of recesses 34. In the present embodiment, each dimension L1 and L2 is greater than the circumferential dimension L3 of the portion including the protrusion 32 and the pair of recesses 34.

[0060] The spatial volume inside the first recess 81 is the same as the spatial volume inside the second recess 82. In addition, in this specification, the "spatial volume inside the recess" refers to the volume of the space surrounded by the outer peripheral surface of the shaft and the inner surface of the recess. In the present embodiment, the spatial volume inside the first recess 81 is the volume of the space surrounded by the outer peripheral surface of the shaft 20 and the inner surface of the first recess 81. The spatial volume inside the second recess 82 is the volume of the space surrounded by the outer peripheral surface of the shaft 20 and the inner surface of the second recess 82.

[0061] The first recess 81a and the first recess 81b are arranged with the center axis J in the radial direction. The first recess 81a is arranged at intervals on one side (+θ side) of the circumferential direction of the protrusion 32. The first recess 81b is arranged at intervals on the other side (-θ side) of the circumferential direction of the protrusion 32. The first recess 81a and the first recess 81b are arranged with the protrusion 32 and a pair of recessed portions 34 in the circumferential direction. In the present embodiment, when viewed in the axial direction, the first recess 81a and the first recess 81b are arranged line-symmetrically with the imaginary lines S1a and S1c as the symmetry axes. Therefore, in the following description, except for the point that it is arranged line-symmetrically with the first recess 81a, the description of the first recess 81b is sometimes omitted for the same structure.

[0062] The center of the first recess 81a in the circumferential direction is arranged offset to the other side (-θ side) in the circumferential direction relative to the imaginary line S1b. The center of the first recess 81b in the circumferential direction is arranged offset to one side (+θ side) in the circumferential direction relative to the imaginary line S1d. That is, the first recesses 81a and 81b satisfy a circumferential arrangement relationship with respect to the imaginary lines S1b and S1d closest to the first recesses 81a and 81b in the circumferential direction when viewed in the axial direction, which is different from the circumferential arrangement relationship of the second recess 82 with respect to the imaginary line S1c overlapping with the second recess 82. Therefore, compared with the case where the circumferential arrangement relationship of the first recesses 81a and 81b with respect to the imaginary lines S1b and S1d and the circumferential arrangement relationship of the second recess 82 with respect to the imaginary line S1c are the same, it is easy to arrange the first recesses 81a and 81b at a position that offsets the change in the weight balance of the rotor 10 in the circumferential direction caused by the provision of the protrusion 32. Thus, even if only one protrusion 32 is provided on the radial inner edge of the through hole 30h, the center of gravity of the rotor 10 can be suppressed from being offset relative to the central axis J. Therefore, when the rotor 10 rotates, the rotor 10 can be suppressed from vibrating and noise can be suppressed. In addition, the number of grooves 21 into which the protrusion 32 fits can be reduced to one, so that the manufacturing cost of the shaft 20 can be suppressed from increasing.

[0063] In the present embodiment, "the arrangement relationship of the first recesses 81a and 81b in the circumferential direction with respect to the imaginary lines S1b and S1d is the same as the arrangement relationship of the second recess 82 in the circumferential direction with respect to the imaginary line S1c" means that, when viewed in the axial direction, the centers of the first recesses 81a and 81b in the circumferential direction overlap with the imaginary lines S1b and S1d in the same manner as the second recess 82. In the present embodiment, assuming that the first recesses 81a and 81b are arranged in this way, the weight of the portion of the rotor core 30 located on the side where the protrusion 32 is provided is greater than the weight of the portion of the rotor core 30 located on the side where the second recess 82 is provided with respect to the imaginary lines S1b and S1d, and the center of gravity of the rotor 10 is offset to the side close to the protrusion 32 with respect to the center axis J.

[0064] In the present embodiment, the first recesses 81a and 81b have an asymmetrical shape across the imaginary lines S1b and S1d passing through the first recesses 81a and 81b when viewed in the axial direction. Therefore, it is easy to appropriately make the weight change caused by the provision of the first recesses 81a and 81b different by using the portion on one side of the circumferential direction across the imaginary lines S1b and S1d and the portion on the other side of the circumferential direction of the rotor core 30. Thus, for example, by making the internal space volume of the portion of the first recesses 81a and 81b closer to the protrusion 32 than the imaginary lines S1b and S1d in the circumferential direction larger than the internal space volume of the portion of the first recesses 81a and 81b farther from the protrusion 32 than the imaginary lines S1b and S1d in the circumferential direction, it is easy to further offset the change in the weight balance of the rotor core 30 in the circumferential direction due to the provision of the protrusion 32. Therefore, it is possible to further suppress the displacement of the center of gravity of the rotor 10 relative to the central axis J.

[0065] In addition, in the present specification, regarding “the recess has an asymmetrical shape with respect to an imaginary line”, it only requires that, when viewed along the axial direction, the shape of a portion of the recess located on one circumferential side of the imaginary line and the shape of a portion of the recess located on the other circumferential side of the imaginary line are not line symmetrical shapes with respect to each other about the imaginary line as the axis of symmetry.

[0066] The first recess 81a includes a first portion 81c and a second portion 81d. The first portion 81c is a portion of the first recess 81a located on the side (-θ side) closer to the protrusion 32 than the imaginary line S1b in the circumferential direction. The second portion 81d is a portion of the first recess 81a located on the side (+θ side) farther from the protrusion 32 than the imaginary line S1b in the circumferential direction. The circumferential dimension L1c of the first portion 81c is larger than the circumferential dimension L1d of the second portion 81d. That is, when viewed in the axial direction, the circumferential dimension L1c of the first portion 81c located on the side closer to the protrusion 32 than the imaginary line S1b in the circumferential direction of the first recess 81a is larger than the circumferential dimension L1d of the second portion 81d located on the side farther from the protrusion 32 than the imaginary line S1b in the circumferential direction of the first recess 81a. Therefore, by providing the first portion 81c, it is easy to reduce the weight of the portion of the rotor core 30 located on the side closer to the protrusion 32 in the circumferential direction. Thus, the weight of the portion near the protrusion 32, which is increased due to the provision of the protrusion 32, can be appropriately reduced by the first portion 81c. Therefore, the circumferential weight balance of the rotor 10 can be more appropriately suppressed from being disrupted, and the center of gravity of the rotor 10 can be more appropriately suppressed from being offset relative to the central axis J.

[0067] When viewed in the axial direction, the circumferential dimension of a portion of the first recess 81b that is closer to the protrusion 32 than the imaginary line S1d in the circumferential direction is greater than the circumferential dimension of a portion of the first recess 81b that is farther from the protrusion 32 than the imaginary line S1d in the circumferential direction. The portion of the first recess 81b that is closer to the protrusion 32 than the imaginary line S1d in the circumferential direction is a portion of the first recess 81b that is located on one side (+θ side) of the imaginary line S1d in the circumferential direction. The portion of the first recess 81b that is farther from the protrusion 32 than the imaginary line S1d in the circumferential direction is a portion of the first recess 81b that is located on the other side (−θ side) of the imaginary line S1d in the circumferential direction.

[0068] In the present embodiment, the first recess 81 is arranged at a position closer to the protrusion 32 than the second recess 82 in the circumferential direction. Therefore, by making the circumferential arrangement relationship of the first recess 81 with respect to the imaginary lines S1b and S1d different from the circumferential arrangement relationship of the second recess 82 with respect to the imaginary line S1c, the weight of the portion of the rotor core 30 close to the protrusion 32 can be more easily changed. Thus, by providing the first recess 81, the weight change of a portion of the rotor core 30 caused by the provision of the protrusion 32 can be more easily offset. Therefore, the circumferential weight balance of the rotor 10 can be further suppressed from being disrupted, and the center of gravity of the rotor 10 can be further suppressed from being shifted relative to the central axis J.

[0069] In the present embodiment, the recessed portion 80 disposed adjacent to the protrusion 32 in the circumferential direction among the plurality of recessed portions 80 is the first recessed portion 81. Therefore, by making the circumferential arrangement relationship of the first recessed portion 81 with respect to the imaginary lines S1b and S1d different from the circumferential arrangement relationship of the second recessed portion 82 with respect to the imaginary line S1c, it is easier to appropriately change the weight of the portion of the rotor core 30 close to the protrusion 32. Thus, by providing the first recessed portion 81, it is easier to appropriately offset the weight change of a portion of the rotor core 30 caused by providing the protrusion 32. Therefore, it is more appropriate to suppress the circumferential balance of the rotor 10 from being destroyed, and it is more appropriate to suppress the center of gravity of the rotor 10 from shifting relative to the central axis J.

[0070] As described above, in the present embodiment, when viewed in the axial direction, the second recess 82 is in a line-symmetrical shape with the imaginary line S1c passing through the second recess 82 as the axis of symmetry. Therefore, even if the second recess 82 is provided, the weight balance of the rotor core 30 in the circumferential direction can be made less likely to be disrupted. In addition, in the present embodiment, the recess 80 arranged on the opposite side of the protrusion 32 in the radial direction across the center axis J is the second recess 82. Therefore, it is possible to suppress the imbalance of the weight of the rotor core 30 caused by the provision of the second recess 82 on both sides across the imaginary line S1c in the circumferential direction, and by providing the second recess 82, it is possible to reduce the weight of the portion of the rotor core 30 located on the radially opposite side of the protrusion 32. As a result, it is possible to further suppress the destruction of the weight balance of the rotor 10 in the circumferential direction, and it is possible to more appropriately suppress the displacement of the center of gravity of the rotor 10 relative to the center axis J.

[0071] As described above, in the present embodiment, the same structure is adopted except that the circumferential positions of the recesses 80 are different, and by arranging a part of the recesses 80, namely the first recess 81, circumferentially close to the protrusion 32 so as to be biased, the change in the circumferential weight balance of the rotor 10 caused by the provision of the protrusion 32 can be offset.

[0072] In this embodiment, the recessed portion 80 is cut out by punching or the like using a die. Figure 4 The laminate 130 shown is manufactured by forming a protruding portion 132 and a pair of recessed portions 134. Figure 4 The stacked body 130 shown is formed by stacking a plurality of plate members 130a in the axial direction. The plate member 130a has the same structure as the plate member 30a except that a part of the recessed portion 80 is not provided. The plurality of plate members 130a have the same shape.

[0073] In addition to the protrusion 32, three protrusions 132 are provided at the radial inner edge of the through hole 130h of the stacked body 130. When viewed in the axial direction, the three protrusions 132 are arranged at positions overlapping with the imaginary lines S1b, S1c, and S1d, respectively. When viewed in the axial direction, the circumferential centers of the three protrusions 132 overlap with the imaginary lines S1b, S1c, and S1d, respectively. The shapes of the three protrusions 132 are the same as the shape of the protrusion 32. The protrusion 132 has the same structure as the protrusion 32 except that the circumferential position is different.

[0074] The arrangement relationship of each protrusion 132 with respect to each imaginary line S1b, S1c, S1d in the circumferential direction is the same as the arrangement relationship of the protrusion 32 with respect to the imaginary line S1a in the circumferential direction. The four protrusions 32, 132 are arranged at equal intervals at intervals of 90° in the circumferential direction. A pair of recessed portions 134 located on both sides of the circumferential direction of each protrusion 132 is provided at the radial inner edge of the through hole 130h. The pair of recessed portions 134 has the same structure as the pair of recessed portions 34 except that they are provided on the protrusion 132.

[0075] The through hole 130h has the same structure as the through hole 30h, except that the protrusion 132 and the recessed portion 134 are provided at the radial inner edge portion instead of the recessed portion 80. The laminated body 130 has the same structure as the rotor core 30, except that the protrusion 132 and the recessed portion 134 are provided at the radial inner edge portion of the through hole 130h instead of the recessed portion 80.

[0076] The worker or the like who manufactures the rotor core 30 uses a die to punch out in the axial direction to cut off the portion of the laminate 130 where the protrusions 132 and the pair of recesses 134 are provided, and forms the recesses 80 in the portion where the protrusions 132 and the pair of recesses 134 are provided. In this way, the rotor core 30 having the recesses 80 is manufactured.

[0077] In addition, in this specification, "operators, etc." include operators who perform various operations and assembly devices, etc. Each operation may be performed only by operators, only by assembly devices, or by operators and assembly devices.

[0078] As described above, the plurality of plate members 30a constituting the rotor core 30 are stacked and rotated at a predetermined angle. That is, the plurality of plate members 130a constituting the stacked body 130 are also stacked and rotated at a predetermined angle. In the present embodiment, the operator who stacks the plate members 130a rotates the one or more plate members 130a by 90° around the central axis J relative to the last stacked plate member 130a each time when stacking one or more plate members 130a. The plate member 130a has a shape that is N-fold symmetrical around the central axis J. When the predetermined angle at which the plate members 130a are rotated and stacked is set to When, meet That is, in this embodiment, the plate member 130a has a shape that is symmetrical four times about the central axis J. Therefore, the shapes of the plurality of plate members 130a can be made identical to each other, and the plurality of plate members 130a can be arranged at a predetermined angle. The rotational lamination is performed to produce a laminated body 130 having protrusions 32 , 132 and recesses 34 , 134 .

[0079] When the stacked body 130 is manufactured as described above, one protrusion 32 is manufactured, and (N-1) protrusions 132 are manufactured. The recesses 80 are respectively manufactured in the portions of the stacked body 130 where the protrusions 132 are provided, and therefore the number of recesses 80 provided in the rotor core 30 is also (N-1). That is, in the rotor core 30, the total number of the protrusions 32 and the recesses 80 is N. As described above, the number of imaginary lines S1 is the same as the total number of the protrusions 32 and the recesses 80, and therefore the number of imaginary lines S1 is also N. Therefore, in the present embodiment, when the plate member 30a constituting the rotor core 30 is rotated and stacked at a predetermined angle, When the number of imaginary lines S1 is N, By satisfying this relationship, a manufacturing method can be adopted in which the stacked body 130 is manufactured by rotationally stacking plate members 130a of the same shape, and the plurality of recesses 80 are manufactured by cutting off the portion where the plurality of protrusions 132 are manufactured. Thus, even when the rotor core 30 having the plurality of rotationally stacked plate members 30a is provided with the protrusions 32 and the plurality of recesses 80, the shapes of the rotationally stacked plate members 130a can be made the same when manufacturing the stacked body 130. Therefore, a single mold can be used for punching out the plate members 130a from the base material, and an increase in the manufacturing cost of the rotor 10 can be suppressed.

[0080] Although not shown in the figure, the rotor core 30 may have a hole portion different from the first magnet holes 51a, 51b and the through hole 30h described above. In this case, for example, when viewed in the axial direction, the hole portion is arranged at a position overlapping with the inter-pole center line Lq, which passes through the circumferential center between the magnet retaining portions 31 adjacent in the circumferential direction and extends in the radial direction. By providing this hole portion, the rotor core 30 can be made lightweight. When viewed in the axial direction, the inter-pole center line Lq passes on the q-axis of the rotor 10. The direction in which the inter-pole center line Lq extends is the q-axis direction of the rotor 10. The inter-pole center line Lq is arranged between the magnet retaining portions 31. The direction in which the pole center line Ld extends and the direction in which the pole center line Lq extends are directions that intersect each other. The pole center line Ld and the inter-pole center line Lq are arranged alternately along the circumferential direction.

[0081] The hole portion may be a hole that penetrates the rotor core 30 in the axial direction. In addition, the hole portion may be a hole having a bottom in the axial direction. For example, a plurality of the hole portions are provided at intervals in the circumferential direction. For example, 8 hole portions may be provided. For example, the respective hole portions are respectively arranged on the radial inner side between the magnet holding portions 31 adjacent to each other in the circumferential direction. For example, the respective hole portions are located on the radial inner side of the first magnet hole 51a in the magnet holding portion 31 of one of the magnet holding portions 31 adjacent to each other in the circumferential direction and the first magnet hole 51b in the magnet holding portion 31 of the other side.

[0082] For example, when viewed in the axial direction, the hole portion may be in a generally triangular shape with rounded corners protruding radially outward. When viewed in the axial direction, for example, the inter-pole center line Lq passes through the circumferential center of the hole portion. For example, when viewed in the axial direction, the hole portion may be in a linearly symmetrical shape with the inter-pole center line Lq passing through the hole portion as the symmetry axis.

[0083] like Figure 1 As shown in the figure, in this embodiment, a flow path 90 for flowing oil O as a refrigerant is provided in the driving device 100. 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. A pump 96 and a cooler 97 are provided in the flow path 90. 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.

[0084] The first flow path portion 91, the second flow path portion 92, and the third flow path portion 93 are provided, for example, on the wall portion of the gear housing 63b. The first flow path portion 91 connects the portion storing the oil O in the interior of the gear housing 63b and the pump 96. The second flow path portion 92 connects the pump 96 and the cooler 97. The third flow path portion 93 connects the cooler 97 and the fourth flow path portion 94. In the present embodiment, the third flow path portion 93 is connected to the end portion on one axial side (+Y side) of the fourth flow path portion 94, that is, the upstream side portion of the fourth flow path portion 94.

[0085] In the present embodiment, the 4th flow path portion 94 is in the shape of a tube extending in the axial direction. In other words, in the present embodiment, the 4th flow path portion 94 is a tube extending in the axial direction. Both axial ends of the 4th flow path portion 94 are supported on the motor housing 63a. The end on one axial side (+Y side) of the 4th flow path portion 94 is supported on the partition wall portion 63d, for example. The end on the other axial side (-Y side) of the 4th flow path portion 94 is supported on the cover portion 63e, for example. The 4th flow path portion 94 is located radially outside the stator 61. In the present embodiment, the 4th flow path portion 94 is located on the upper side of the stator 61.

[0086] The fourth flow path portion 94 has a supply port 94a for supplying the oil O to the stator 61. In the present embodiment, the supply port 94a is an injection port for injecting a portion of the oil O flowing into the fourth flow path portion 94 to the outside of the fourth flow path portion 94. The supply port 94a is composed of a hole penetrating the wall portion of the fourth flow path portion 94 from the inner peripheral surface to the outer peripheral surface. A plurality of supply ports 94a are provided in the fourth flow path portion 94.

[0087] The fifth flow path portion 95 connects the fourth flow path portion 94 and the inside of the hollow shaft 20. More specifically, the fifth flow path portion 95 connects the end portion on the other axial side (-Y side) of the fourth flow path portion 94 and the end portion on the other axial side of the shaft 20. In the present embodiment, the fifth flow path portion 95 is provided on the cover portion 63e.

[0088] like Figure 1 As shown, when the pump 96 is driven, the oil O stored in the gear housing 63b is sucked up through the first flow path portion 91, and flows into the cooler 97 through the second flow path portion 92. The oil O flowing into the cooler 97 is cooled in the cooler 97, and then flows into the fourth flow path portion 94 through the third flow path portion 93. A part of the oil O flowing into the fourth flow path portion 94 is ejected from the supply port 94a and supplied to the stator 61. Another part of the oil O flowing into the fourth flow path portion 94 flows into the interior of the shaft 20 through the fifth flow path portion 95.

[0089] The oil O flowing into the shaft 20 from the fifth flow path portion 95 flows toward one axial side (toward the +Y side) in the shaft 20. A portion of the oil O flowing inside the shaft 20 flows from the hole portion 22 of the shaft 20 into a groove provided in a plate disposed between the core member portions. The oil O flowing into the groove flows radially outward and flows into the hole portion (not shown) described above. The oil O flowing into the hole portion flows in the axial direction, as shown in FIG. Figure 1 As shown, the particles scatter radially outward from the axial end of the rotor core 30 toward the stator 61 .

[0090] Another part of the oil O flowing inside the shaft 20 is discharged from the opening on one axial side of the shaft 20 to the inside of the gear housing 63b and is stored again in the gear housing 63b. The oil O supplied to the stator 61 from the supply port 94a and the hole portion (not shown) falls downward and is stored in the lower area of ​​the motor housing 63a. The oil O stored in the lower area of ​​the motor housing 63a returns to the gear housing 63b via the partition wall opening 63f provided in the partition wall portion 63d.

[0091] Hereinafter, embodiments different from the first embodiment will be described. In the description of each of the following embodiments, for the same structure as the first embodiment, the description is sometimes omitted by appropriately marking the same reference numerals, etc. In addition, as the structure omitted from description in each of the following embodiments, the same structure as the first embodiment may be adopted within the scope of non-contradiction.

[0092] <Second embodiment>

[0093] like Figure 5 As shown, in the rotor core 230 of the rotor 210 of the present embodiment, three recesses 280 are provided at the radial inner edge of the through hole 230h. The three recesses 280 include two first recesses 281 and one second recess 282. The two first recesses 281 include a first recess 281a and a first recess 281b. When viewed in the axial direction, the first recess 281a overlaps with the imaginary line S1b. When viewed in the axial direction, the first recess 281b overlaps with the imaginary line S1d. When viewed in the axial direction, the center of the circumferential direction of the first recess 281a overlaps with the imaginary line S1b. When viewed in the axial direction, the center of the circumferential direction of the first recess 281b overlaps with the imaginary line S1d. That is, in this embodiment, when viewed in the axial direction, the circumferential configuration relationship of the first recess 281 relative to the imaginary lines S1b, S1d closest to the first recess 281 in the circumferential direction is the same as the circumferential configuration relationship of the second recess 82 relative to the imaginary line S1c overlapping with the second recess 82.

[0094] In the present embodiment, the circumferential dimension of the first recess 281 is the same as the circumferential dimension of the second recess 82. The circumferential dimension of the first portion 281c located on the side (-θ side) closer to the protrusion 32 than the imaginary line S1b in the circumferential direction is the same as the circumferential dimension of the second portion 281d located on the side (+θ side) farther from the protrusion 32 than the imaginary line S1b in the circumferential direction in the first recess 281a. The first portion 281c is recessed radially outwardly relative to the second portion 281d. When viewed in the axial direction, the first recess 281a has an asymmetric shape across the imaginary line S1b passing through the first recess 281a. The spatial volume inside the first portion 281c is larger than the spatial volume inside the second portion 281d. In the present embodiment, the spatial volume inside the first recess 281 is larger than the spatial volume inside the second recess 82.

[0095] When viewed in the axial direction, the shape of the first recess 281a is different from the shape of the second recess 82. In addition, when viewed in the axial direction, the shape of the first recess 281b is the same as the shape of the first recess 281a, except that the imaginary lines S1a and S1c are symmetrically arranged, and is different from the shape of the second recess 82. That is, in the present embodiment, the first recess 281 satisfies the requirement of having a shape different from the second recess 82 when viewed in the axial direction. By making the shape of the first recess 281 different from the shape of the second recess 82 in this way, it is easy to make the first recess 281 a shape that offsets the change in the weight balance of the rotor 10 in the circumferential direction due to the provision of the protrusion 32. Therefore, even if the protrusion 32 is provided at the radial inner edge of the through hole 230h, the center of gravity of the rotor 210 can be suppressed from shifting relative to the central axis J. Therefore, when the rotor 210 rotates, the vibration of the rotor 210 can be suppressed, and the generation of noise can be suppressed.

[0096] In the present embodiment, the first portion 281c on the side of the first recess 281 that is circumferentially closer to the protrusion 32 is recessed radially outward relative to the second portion 281d on the side of the first recess 281 that is circumferentially farther from the protrusion 32, thereby increasing the volume of the space in the portion of the first recess 281 that is provided closer to the protrusion 32. Thus, by providing the first recess 281, it is possible to easily and appropriately offset the change in the circumferential weight balance of the rotor core 230 caused by providing the protrusion 32. Therefore, it is possible to further suppress the deviation of the center of gravity of the rotor 210 relative to the central axis J.

[0097] As described above, in the first embodiment, the weight change of the rotor core 30 caused by the provision of the protrusion 32 is offset by circumferentially shifting the first recess 81 toward the direction close to the protrusion 32. In contrast, in the present embodiment, the portion of the first recess 281 that is circumferentially close to the protrusion 32 is expanded radially outward to increase the internal space volume, thereby offsetting the weight change of the rotor core 230 caused by the provision of the protrusion 32.

[0098] The other structures of the through hole 230h are the same as the other structures of the through hole 30h of the first embodiment. The other structures of the rotor core 230 are the same as the other structures of the rotor core 30 of the first embodiment.

[0099] <Third embodiment>

[0100] like Figure 6 As shown, in the present embodiment, a plurality of imaginary lines S2 are provided for explanation, and the plurality of imaginary lines S2 extend radially outward from the central axis J when viewed in the axial direction, are arranged at equal intervals in the circumferential direction, and the number is the same as the total number of the protrusions 32 and the number of the recesses 380 added together. In the present embodiment, the number of the protrusions 32 is one, and the number of the recesses 380 is seven. Therefore, in the present embodiment, the plurality of imaginary lines S2 are provided with imaginary lines S2a to S2h totaling these eight imaginary lines. The eight imaginary lines S2a to S2h are arranged at intervals of 45° in the circumferential direction. The imaginary line S2a is an imaginary line S2 that overlaps with the center of the circumferential direction of the protrusion 32 when viewed in the axial direction. The imaginary lines S2b, S2c, S2d, S2e, S2f, S2g, and S2h are arranged in order from the imaginary line S2a toward one side (+θ side) in the circumferential direction at intervals of 45°. In the present embodiment, the plate members constituting the rotor core 330 are rotated and stacked at a predetermined angle of 45°.

[0101] When viewed in the axial direction, each recess 380 overlaps with each imaginary line S2b to S2h. The plurality of recesses 380 include a first recess 381 and a second recess 382. Two first recesses 381 are provided. Five second recesses 382 are provided. The two first recesses 381 are recesses 380 that are arranged adjacent to the protrusion 32 in the circumferential direction and separated by the protrusion 32 in the circumferential direction. When viewed in the axial direction, one first recess 381 overlaps with the imaginary line S2b. When viewed in the axial direction, the other first recess 381 overlaps with the imaginary line S2h. When viewed in the axial direction, the circumferential center of each first recess 381 overlaps with the imaginary lines S2b and S2h, respectively.

[0102] When viewed in the axial direction, the five second recesses 382 overlap with the five imaginary lines S2c, S2d, S2e, S2f, and S2g, respectively. When viewed in the axial direction, the circumferential center of each second recess 382 overlaps with the imaginary lines S2c, S2d, S2e, S2f, and S2g, respectively. In the present embodiment, when viewed in the axial direction, the shape of the first recess 381 and the shape of the second recess 382 are similar shapes, and are the same shape as each other. When viewed in the axial direction, the shape of the first recess 381 and the shape of the second recess 382 are, for example, the same as the shape of the recess 80 of the first embodiment.

[0103] In the present embodiment, the volume of the space inside the first recess 381 is larger than the volume of the space inside the second recess 382. When viewed in the axial direction, the size of the first recess 381 is larger than the size of the second recess 382. The radial dimension of the first recess 381 is larger than the radial dimension of the second recess 382. The circumferential dimension of the first recess 381 is larger than the circumferential dimension of the second recess 382. That is, in the present embodiment, the first recess 381 satisfies the circumferential dimension different from that of the second recess 382 when viewed in the axial direction. Therefore, it is easy to make the circumferential dimension of the first recess 381 a dimension that offsets the change in the weight balance of the rotor 310 in the circumferential direction due to the provision of the protrusion 32. Therefore, even if the protrusion 32 is provided at the radial inner edge of the through hole 330h, the center of gravity of the rotor 310 can be suppressed from shifting relative to the central axis J. Therefore, when the rotor 310 rotates, the vibration of the rotor 310 can be suppressed, and the generation of noise can be suppressed.

[0104] As described above, in the present embodiment, among the plurality of recesses 380 arranged at equal intervals in the circumferential direction together with the protrusion 32, two recesses 380 arranged adjacent to each other in the circumferential direction of the protrusion 32 are set as the first recesses 381 and the circumferential dimensions are made larger than those of the other recesses 380, so that the weight change of the rotor core 330 caused by the provision of the protrusion 32 can be appropriately offset. In addition, in the present embodiment, the shape of the first recess 381 and the shape of the second recess 382 are made the same when viewed in the axial direction, and the size of the first recess 381 is made larger than that of the second recess 382, ​​so that the weight change of the rotor core 330 caused by the provision of the protrusion 32 can be appropriately offset.

[0105] The present invention is not limited to the above-mentioned embodiments, and other structures and other methods may be adopted within the scope of the technical concept of the present invention. The first recess only needs to satisfy at least one of the following conditions: the circumferential configuration relationship relative to the imaginary line closest to the first recess in the circumferential direction when viewed in the axial direction is different from the circumferential configuration relationship of the second recess relative to the imaginary line overlapping with the second recess; it has a different shape from the second recess when viewed in the axial direction; and it has a different circumferential size from the second recess when viewed in the axial direction. The first recess may satisfy any two of the three conditions, or all three. In addition, in the case of including multiple first recesses, the multiple first recesses may include more than two first recesses that satisfy different conditions among the above three conditions. It is also possible that when viewed in the axial direction, the first recess does not overlap with the specified imaginary line. The number of first recesses can be one or more, and there is no special limitation. The shape of the first recess is not particularly limited.

[0106] The shape of the second recess is not particularly limited. The second recess can be arranged arbitrarily relative to the imaginary line as long as it overlaps with the imaginary line when viewed in the axial direction. The number of the second recesses can be one or more and is not particularly limited. The circumferential arrangement of the first recess and the second recess is not particularly limited.

[0107] When the rotor core has a plurality of plate members stacked in the axial direction, the plurality of plate members may be stacked in a rotational manner at any predetermined angle. When the number of imaginary lines is set to N, it does not satisfy In this case, for example, The plurality of plate components may not be stacked in a rotational manner.

[0108] The number of protrusions provided on the radial inner edge of the through hole can be at least one and is not particularly limited. The circumferential position of the protrusion is not particularly limited. It is also possible that, when viewed axially, the protrusion does not overlap with the magnetic pole center line that passes through the circumferential center of the magnetic pole portion and extends radially. It is also possible that, when viewed axially, the protrusion overlaps with the inter-pole center line Lq of the above-mentioned embodiment. It is also possible not to provide recessed portions on both circumferential sides of the protrusion.

[0109] The configuration of the magnets fixed to the rotor core and the number of magnets are not particularly limited. For example, in addition to the pair of first magnet holes 51a, 51b and the pair of first magnets 41a, 41b in the above-mentioned embodiment, a second magnet hole located radially outside the first magnet holes 51a, 51b and a second magnet arranged in the second magnet hole can also be provided. In this case, for example, the second magnet hole and the second magnet can be provided in pairs in each magnetic pole portion in a manner that the magnetic pole center line Ld is separated in the circumferential direction when viewed in the axial direction. In this case, it is also possible that when viewed in the axial direction, the pair of second magnet holes and the pair of second magnets extend in a direction that separates from each other in the circumferential direction as they move from the radial inside to the radial outside. In more detail, it is also possible that when viewed in the axial direction, the pair of second magnet holes and the pair of second magnets are arranged in a V-shaped configuration that expands in the circumferential direction as they move toward the radial outside. In this way, in each magnetic pole portion of the rotor, two pairs of magnets arranged along a V-shaped configuration when viewed in the axial direction can be arranged radially. In addition, the second magnet hole and the second magnet may be provided one each in each magnetic pole portion, and extend in a direction perpendicular to the magnetic pole center line Ld when viewed in the axial direction. In this case, in each magnetic pole portion of the rotor, a pair of first magnets and a second magnet may be provided along the axial direction. Shape configuration.

[0110] The rotary electric machine to which the present invention is applied is not limited to a motor, but may also be a generator. The use of the rotary electric machine is not particularly limited. The rotary electric machine may be mounted on equipment other than a vehicle. The use of the drive device to which the present invention is applied is not particularly limited. The drive device may be mounted on a vehicle for purposes other than rotating an axle, for example, or may be mounted on equipment other than a vehicle. The posture when using the rotary electric machine and the drive device is not particularly limited. The central axis of the rotary electric machine may be inclined relative to a horizontal direction perpendicular to the vertical direction, or may extend in the vertical direction.

[0111] In addition, the present technology can adopt the following structures.

[0112] (1) A rotor capable of rotating about a central axis, wherein the rotor comprises: a shaft extending in an axial direction; and a rotor core fixed to the shaft, the rotor core comprising: a through hole through which the shaft passes in an axial direction; a protrusion provided at a radially inner edge of the through hole and protruding radially inward; and a plurality of recesses provided at intervals in the circumferential direction at the radially inner edge of the through hole and recessed radially outward, wherein when a plurality of imaginary lines are defined, one of the plurality of imaginary lines overlaps with the circumferential center of the protrusion when viewed in the axial direction, and the plurality of imaginary lines extend radially outward from the central axis when viewed in the axial direction. The plurality of recesses extend and are arranged at equal intervals in the circumferential direction and are the same in number as the sum of the number of the protrusions and the number of the recesses, wherein the plurality of recesses include: a first recess; and a second recess, which overlaps with the imaginary line when viewed in the axial direction, and the first recess satisfies at least one of the following conditions: when viewed in the axial direction, the circumferential configuration relationship relative to the imaginary line closest to the first recess in the circumferential direction is different from the circumferential configuration relationship of the second recess relative to the imaginary line overlapping with the second recess; when viewed in the axial direction, has a shape different from that of the second recess; and when viewed in the axial direction, has a circumferential size different from that of the second recess.

[0113] (2) The rotor according to (1), wherein the first recess overlaps the imaginary line when viewed in the axial direction, and has an asymmetric shape across the imaginary line passing through the first recess.

[0114] (3) A rotor according to (2), wherein, when viewed in the axial direction, the circumferential dimension of a portion of the first recess that is circumferentially closer to the protrusion than the imaginary line is larger than the circumferential dimension of a portion of the first recess that is circumferentially farther from the protrusion than the imaginary line.

[0115] (4) The rotor according to any one of (1) to (3), wherein the first recessed portion is arranged at a position closer to the protruding portion than the second recessed portion in the circumferential direction.

[0116] (5) The rotor according to any one of (1) to (4), wherein the recessed portion arranged adjacent to the protruding portion in the circumferential direction among the plurality of recessed portions is the first recessed portion.

[0117] (6) The rotor according to any one of (1) to (5), wherein the plurality of recessed portions have the same shape as one another when viewed in the axial direction.

[0118] (7) The rotor according to any one of (1) to (6), wherein the second recessed portion has a line-symmetrical shape with the imaginary line passing through the second recessed portion as an axis of symmetry when viewed in the axial direction.

[0119] (8) A rotor according to (7), wherein the plurality of recesses include the recess that is arranged on the opposite side of the protrusion in the radial direction across the center axis, and the recess that is arranged on the opposite side of the protrusion in the radial direction across the center axis is the second recess.

[0120] (9) A rotor according to any one of (1) to (8), wherein the rotor core has a plurality of plate members stacked in the axial direction, wherein the plate members are stacked in a state where one or more of the plate members are rotated at a predetermined angle, and when the predetermined angle is set to When the number of the imaginary lines is set to N,

[0121] (10) A rotor according to any one of (1) to (9), wherein the rotor has a plurality of magnetic pole portions arranged at intervals along the circumferential direction, and when viewed in the axial direction, the protrusion is arranged at a position overlapping with a magnetic pole center line, and the magnetic pole center line passes through the circumferential center of the magnetic pole portion and extends radially.

[0122] (11) A rotor according to any one of (1) to (10), wherein a pair of recessed portions recessed radially outward are provided at the radial inner edge portion of the through hole, and the pair of recessed portions are arranged adjacent to the protrusion in the circumferential direction with the protrusion sandwiched therebetween.

[0123] (12) A rotating electrical machine comprising: the rotor according to any one of (1) to (11); and a stator facing the rotor with a gap therebetween in a radial direction.

[0124] (13) A driving device comprising: the rotating electric machine described in (12); and a gear mechanism connected to the rotating electric machine.

[0125] The configurations described above in this specification can be appropriately combined within a range that does not contradict each other.

[0126] Description of symbols

[0127] 10, 210, 310: rotor; 10N, 10P, 10S: magnetic pole portion; 20: shaft; 30, 230, 330: rotor core; 30a: plate member; 30h, 230h, 330h: through hole; 32: protrusion; 34: recess; 60: rotating electrical machine; 61: stator; 70: gear mechanism; 80, 280, 380: recess; 81, 81a, 81b, 281, 281a, 281b, 381: first recess; 82, 382: second recess; 100: drive device; J: center axis; Ld: magnetic pole center line; S1, S1a, S1b, S1c, S1d, S2, S2a, S2b, S2c, S2d, S2e, S2f, S2g, S2h: imaginary line; Specify the angle.

Claims

1. A rotor capable of rotating about a central axis, wherein: The rotor has: a shaft extending in an axial direction; and a rotor core fixed to the shaft, The rotor core has: A through hole, through which the shaft passes in the axial direction; a protrusion, which is provided at a radial inner edge of the through hole and protrudes radially inward; and A plurality of recesses are provided at intervals in the circumferential direction on the radial inner edge of the through hole and are recessed toward the radial outer side. When a plurality of imaginary lines are specified, one of the plurality of imaginary lines overlaps with the circumferential center of the protrusion when viewed in the axial direction, and the plurality of imaginary lines extend radially outward from the central axis when viewed in the axial direction, are arranged at equal intervals in the circumferential direction, and the number of the imaginary lines is the same as the total number of the protrusions and the recesses. The plurality of recesses include: a first recess; and The second recessed portion overlaps with the imaginary line when viewed along the axial direction. The first recess satisfies at least one of the following conditions: When viewed in the axial direction, the circumferential arrangement relationship of the second recess relative to the imaginary line closest to the first recess in the circumferential direction is different from the circumferential arrangement relationship of the second recess relative to the imaginary line overlapping the second recess; When viewed along the axial direction, it has a shape different from that of the second recess; as well as When viewed in the axial direction, it has a circumferential dimension different from that of the second recessed portion.

2. The rotor according to claim 1, wherein: The first recess overlaps with the imaginary line when viewed in the axial direction, and has an asymmetrical shape across the imaginary line passing through the first recess.

3. The rotor according to claim 2, wherein: When viewed in the axial direction, a portion of the first recess that is circumferentially closer to the protrusion than the imaginary line has a larger circumferential dimension than a portion of the first recess that is circumferentially farther from the protrusion than the imaginary line.

4. The rotor according to claim 1, wherein: The first recessed portion is disposed at a position closer to the protruding portion than the second recessed portion in the circumferential direction.

5. The rotor according to claim 1, wherein: The recessed portion, among the plurality of recessed portions, that is arranged adjacent to the protruding portion in the circumferential direction is the first recessed portion.

6. The rotor according to claim 1, wherein: When viewed in the axial direction, the plurality of recessed portions have the same shape as one another.

7. The rotor according to any one of claims 1 to 6, wherein: When viewed in the axial direction, the second recessed portion has a line-symmetrical shape with the imaginary line passing through the second recessed portion as an axis of symmetry.

8. The rotor according to claim 7, wherein: The plurality of recessed portions include the recessed portion disposed on the opposite side of the protruding portion across the central axis in the radial direction. The recessed portion disposed on the opposite side of the protruding portion across the central axis in the radial direction is the second recessed portion.

9. The rotor according to any one of claims 1 to 6, wherein: The rotor core includes a plurality of plate members stacked in the axial direction. The plate members are stacked in a state where one or more of the plate members are rotated at a predetermined angle. When the prescribed angle is set to When the number of the imaginary lines is set to N, 10. The rotor according to any one of claims 1 to 6, wherein: The rotor has a plurality of magnetic poles arranged at intervals in the circumferential direction. When viewed in the axial direction, the protrusion is arranged at a position overlapping with a magnetic pole center line that passes through the center of the circumference of the magnetic pole portion and extends in the radial direction.

11. The rotor according to any one of claims 1 to 6, wherein: A pair of recessed portions recessed radially outward are provided at the radial inner edge of the through hole. The pair of recessed portions are arranged adjacent to the protruding portion across the protruding portion in the circumferential direction.

12. A rotating electrical machine, comprising: A rotor as claimed in any one of claims 1 to 6; and The stator faces the rotor with a gap therebetween in the radial direction.

13. A driving device, comprising: The rotating electrical machine according to claim 12; and A gear mechanism is connected to the rotating motor.

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