CN111511598B

CN111511598B - In-wheel motor

Info

Publication number: CN111511598B
Application number: CN201880080762.3A
Authority: CN
Inventors: 山口康夫
Original assignee: Nidec Corp
Current assignee: Nidec Corp
Priority date: 2017-12-18
Filing date: 2018-12-11
Publication date: 2023-06-16
Anticipated expiration: 2038-12-11
Also published as: WO2019124152A1; CN111511598A

Abstract

One embodiment of the present invention is an in-wheel motor, including: a motor section having a rotor and a stator; a speed reducer unit connected to the rotor for reducing the rotation of the rotor; a housing fixed to the vehicle and having a housing portion for housing the motor portion and the speed reducer portion; and a wheel connected to the decelerator portion. The rotor has: an input shaft extending along a central axis; a rotor magnet; and a rotor holder that holds the input shaft and the rotor magnet. The rotor holder has: a cylindrical portion to which a rotor magnet is fixed on an outer peripheral surface; and a circular plate portion positioned at one opening of the cylindrical portion, to which the input shaft is fixed. The speed reducer section has: a sun gear provided on an outer peripheral surface of the input shaft; a plurality of planetary gears; a gear ring; a plurality of carrier pins that support the plurality of planetary gears, respectively; and a wheel carrier that holds the plurality of wheel carrier pins. At least a part of the planetary gear is housed inside the cylindrical portion in the radial direction.

Description

In-wheel motor

Technical Field

The present invention relates to an in-wheel motor. The present application claims priority based on U.S. patent provisional application 62/599,870 filed on 12 months 18 in 2017 and U.S. patent provisional application 62/627,287 filed on 7 months 2 in 2018, the contents of which are incorporated herein by reference.

Background

In-wheel motors are disclosed in japanese laid-open patent publication No. 2017-159883, as follows: a motor unit that directly drives the wheel is provided in the wheel.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open publication No. 2017-159883

Disclosure of Invention

Problems to be solved by the invention

In the in-wheel motor, the motor unit is housed inside the wheel, and therefore miniaturization of the motor unit is demanded.

In view of the above problems, an object of one embodiment of the present invention is to provide an in-wheel motor in which a motor unit is miniaturized.

Means for solving the problems

One aspect of the present invention is an in-wheel motor mounted on a vehicle, wherein the in-wheel motor has: a motor unit having a rotor that rotates around a central axis and an annular stator that is positioned radially outward of the rotor; a speed reducer unit connected to the rotor for reducing the rotation of the rotor; a housing fixed to the vehicle and having a housing portion that houses the motor portion and the speed reducer portion; and a wheel connected to the speed reducer section, and transmitting rotation of the rotor through the speed reducer section. The rotor has: an input shaft extending along the central axis; a rotor magnet radially opposed to the stator; and a rotor holder that holds the input shaft and the rotor magnet. The rotor holder has: a cylindrical portion having a cylindrical shape centered on the central axis, the rotor magnet being fixed to an outer peripheral surface thereof; and a disk portion that is positioned in one opening of the cylindrical portion and to which the input shaft is fixed. The speed reducer section has: a sun gear provided on an outer peripheral surface of the input shaft; a plurality of planetary gears disposed radially outward of the sun gear and meshed with the sun gear; a ring gear disposed radially outward of the plurality of planetary gears and meshed with the plurality of planetary gears; a plurality of carrier pins inserted into gear center holes provided in the planetary gears, the carrier pins supporting the plurality of planetary gears, respectively; and a wheel carrier that holds a plurality of the wheel carrier pins. At least a part of the planetary gear is housed inside the cylindrical portion in the radial direction.

Effects of the invention

According to one embodiment of the present invention, an in-wheel motor is provided in which a motor unit is miniaturized.

Drawings

FIG. 1 is a cross-sectional view of an in-wheel motor of one embodiment along the X-Z plane.

FIG. 2 is a cross-sectional view of an in-wheel motor of one embodiment along the X-Y plane.

Fig. 3 is a cross-sectional view of the motor unit of one embodiment along the central axis J.

Fig. 4 is a cross-sectional view of the motor unit of one embodiment perpendicular to the central axis J.

Fig. 5 is a cross-sectional view of a pump section according to one embodiment.

Fig. 6 is a cross-sectional view of the motor unit of modification 1 taken along the central axis J.

Fig. 7 is a partial cross-sectional view of the in-wheel motor of modification 2.

Fig. 8 is a partial cross-sectional view of the motor unit of modification 3.

Detailed Description

Hereinafter, an in-wheel motor and a motor unit included in the in-wheel motor according to an embodiment of the present invention will be described with reference to the drawings. In the drawings used in the following description, for the sake of easy understanding of the features, portions to be characterized may be enlarged for convenience, and the dimensional proportions of the respective constituent elements are not necessarily the same as the actual ones.

The XYZ coordinate system is appropriately shown in each figure. The X-axis direction of each drawing is a direction parallel to the axial direction of the central axis J shown in fig. 1. In the following description, the positive side in the Z-axis direction (+z-side, one side) is referred to as "upper side", and the negative side in the Z-axis direction (-Z-side, the other side) is referred to as "lower side". The upper and lower sides are for illustration only, and are not limited to the actual positional relationship and orientation. Unless otherwise specified, a direction (X-axis direction) parallel to the central axis J is simply referred to as an "axial direction" or an "up-down direction", a radial direction centered on the central axis J is simply referred to as a "radial direction", and a circumferential direction centered on the central axis J, that is, a direction around the central axis J is simply referred to as a "circumferential direction". In the following description, "planar view" refers to a state as viewed from the axial direction.

In the following description, the direction in which the central axis J extends is referred to as the axial direction. The center axis J coincides with the width direction of the vehicle. In the following description, the +x side (left side in the drawing) may be referred to as "one axial side", "one side", or "outer side in the vehicle width direction", and the-X side (right side in the drawing) may be referred to as "other axial side", "other side", or "inner side in the vehicle width direction".

In addition, in the present specification, "extending in the axial direction" includes, in addition to extending strictly in the axial direction (i.e., the direction parallel to the X axis), extending in a direction inclined within a range of less than 45 ° with respect to the axial direction. In the present specification, "extending along the central axis J" means extending in the axial direction centering on the central axis J. In the present specification, "radially extending" includes, in addition to extending strictly in the radial direction, that is, in a direction perpendicular to the axial direction, extending in a direction inclined within a range of less than 45 ° with respect to the radial direction.

< in-wheel Motor >)

Fig. 1 and 2 are cross-sectional views of the in-wheel motor 1 of the present embodiment taken along the center axis J. Fig. 3 is a cross-sectional view of the motor unit 2 included in the in-wheel motor 1 along the center axis J. In addition, fig. 1 is a sectional view taken along the X-Z plane, and fig. 2 and 3 are sectional views taken along the X-Y plane. Fig. 4 is a cross-sectional view of the motor unit 2 perpendicular to the central axis J.

As shown in fig. 1, an in-wheel motor 1 of the present embodiment is mounted on a vehicle 9 of a general automobile, for example. However, the in-wheel motor 1 may be mounted on a vehicle such as a motorcycle, a bicycle, or a wheelchair.

The in-wheel motor 1 of the present embodiment includes a motor unit 2, a hub frame 50, a hub bearing 60, a brake unit 70, and a wheel 3.

The motor unit 2 includes a motor portion 10, a speed reducer portion 20, a bearing member (1 st bearing member) 4, a resolver 5, a pump portion 30, oil O, and a housing 40. That is, in-wheel motor 1 includes motor unit 10, speed reducer unit 20, bearing member 4, pump unit 30, oil O, and casing 40.

The motor unit 10 is an electric motor as a power source of the in-wheel motor 1. The speed reducer section 20 has an output shaft 29 that rotates about a central axis J extending in a direction perpendicular to the up-down direction. The speed reducer section 20 reduces the rotation of the motor section 10 and outputs the reduced rotation from the output shaft 29. The output shaft 29 transmits the power of the motor unit 2 to the wheel 3. The housing 40 houses the motor unit 10, the speed reducer unit 20, the pump unit 30, and the oil O.

< hub frame >)

The hub carrier 50 extends along a plane perpendicular to the central axis J. The hub carrier 50 is a disk-shaped member centered on the center axis J. A center hole 50a is provided in the center of the hub frame 50 in a plan view. The output shaft 29 is inserted through the center hole 50a. In addition, a hub bearing 60 is located in the central bore 50a. The hub carrier 50 rotatably supports the output shaft 29 via a hub bearing 60.

The hub frame 50 has a bearing holding portion 51, an inclined portion 52, a hub frame flange portion 53, and a pair of coupling portions (knuckle) 54. The bearing holding portion 51, the inclined portion 52, and the hub frame flange portion 53 are connected to each other to form a circular plate shape. The bearing holding portion 51, the inclined portion 52, and the hub frame flange portion 53 are arranged in this order from the radially inner side to the radially outer side.

The center hole 50a is provided in the center of the bearing holder 51 in a plan view. The bearing holding portion 51 is provided with a screw hole (not shown) that is fastened to a fixing screw 64 that fixes the outer ring 61 of the hub bearing 60. That is, the hub frame 50 holds the outer ring 61 of the hub bearing 60 at the bearing holding portion 51.

The inclined portion 52 extends radially outward from the outer end of the bearing holder 51. The inclined portion 52 is inclined toward the vehicle width direction inner side (axial other side) as it is directed toward the radial outer side. That is, the inclined portion 52 has a conical shape.

The hub frame flange portion 53 extends radially outward from the inclined portion 52. The hub frame flange portion 53 is provided with a plurality of screw holes 53a extending in the axial direction. That is, the hub carrier 50 is provided with a plurality of screw holes 53a. The plurality of screw holes 53a are arranged in the circumferential direction. The plurality of screw holes 53a are fastened with fixing screws 59 for fixing the housing 40 of the motor unit 2 to the hub frame 50.

The hub frame flange portion 53 has a 1 st fitting surface 53j facing radially inward at a connection portion with the inclined portion 52. The 1 st fitting surface 53j extends in the circumferential direction. As described in the following section, the 1 st fitting surface 53j is fitted to the 2 nd fitting surface 43j of the housing 40.

A pair of coupling portions 54 are provided at the upper and lower ends of the hub frame flange portion 53. The connection portions 54 are connected to a pair of arms 9a provided in the vehicle 9. That is, the hub frame 50 is fixed to the vehicle 9 at the coupling portion 54.

< hub bearing >

The hub bearing 60 is located inside the central bore 50a of the hub frame 50. The hub bearing 60 rotatably supports the output shaft 29 with respect to the hub carrier 50. The hub bearing 60 has an outer ring 61, an inner ring 62, and a plurality of rolling elements 63 located between the outer ring 61 and the inner ring 62.

The hub bearing 60 of the present embodiment is a multi-row ball bearing. Accordingly, the hub bearing 60 has a plurality of rolling elements 63. The plurality of rolling elements 63 are arranged in two rows in the axial direction in the circumferential direction. However, the hub bearing 60 may be a bearing member of another structure.

The hub bearing 60 is detachably fixed to the hub frame 50. Specifically, the outer ring 61 of the hub bearing 60 is detachably fixed to the bearing holding portion 51 of the hub frame 50 by a fixing screw 64.

The inner ring 62 of the hub bearing 60 holds the output shaft 29. An inner spline is provided on the inner peripheral surface 62c of the inner ring 62. On the other hand, an external spline is provided on the outer peripheral surface 29d of the output shaft 29. The inner race 62 is splined to the output shaft 29. Thereby, the relative rotation between the inner race 62 and the output shaft 29 in the circumferential direction is restricted. That is, the inner race 62 rotates together with the output shaft 29.

The inner race 62 of the hub bearing 60 has a 1 st member 62A and a 2 nd member 62B. The 1 st member 62A and the 2 nd member 62B are fixed to each other. The 1 st member 62A and the 2 nd member 62B are respectively disposed radially inward of the different rolling elements 63, and contact the rolling elements 63.

As shown in fig. 2, the 1 st member 62A of the inner ring 62 has a hub bearing flange portion (wheel mounting portion) 62A extending radially outward. The hub bearing flange portion 62a extends outward (axially toward one side) in the vehicle width direction with respect to the outer ring 61 of the hub bearing 60. The hub bearing flange portion 62a is provided with a plurality of screw holes 62b arranged in the circumferential direction. The screw hole 62b is fastened to a fixing screw 69, and the fixing screw 69 fixes the inner ring 62, the wheel 3, and the disc rotor 72 of the brake portion 70 to each other. That is, the wheel 3 and the disc rotor 72 are fixed to the inner ring 62.

< Shell >

As shown in fig. 1, the housing 40 is located on the vehicle width direction inner side (the other axial side) with respect to the hub frame 50. The housing 40 is fixed to the vehicle 9 via a hub carrier 50. The housing 40 includes a housing portion 49 that houses the motor portion 10, the speed reducer portion 20, and the pump portion 30.

The oil O is stored in the storage portion 49. The oil O is accumulated in a lower region of the housing portion 49. In the present specification, the "lower region of the housing portion 49" includes a portion located below the center (i.e., the central axis J) of the housing portion 49 in the vertical direction.

The housing portion 49 is provided with an oil passage 80 through which the oil supply O circulates in the housing portion 49. The pump unit 30 is provided in the path of the oil passage 80.

As shown in fig. 3, the case 40 includes a tubular member 41, a 1 st bottom plate 42, a 2 nd bottom plate 43, a cover 44, and a sealing member 6. The housing portion 49 is a space surrounded by the tubular member 41, the 1 st bottom plate 42, and the 2 nd bottom plate 43.

The tubular member 41 has a cylindrical shape centered on the central axis J. The cylindrical member 41 extends in the axial direction. The cylindrical member 41 is open on both sides in the axial direction. The motor portion 10 and the speed reducer portion 20 are housed radially inside the tubular member 41.

As shown in fig. 1, the tubular member 41 has a plurality of fixing plate portions 41b protruding radially outward. The fixing plate portion 41b has a plate shape extending in a direction perpendicular to the central axis J. The plurality of fixing plate portions 41b are arranged in the circumferential direction. Each of the fixing plate portions 41b is provided with a through hole 41c penetrating in the axial direction. That is, the case 40 is provided with a plurality of through holes 41c. A fixing screw 59 for fixing the housing 40 to the hub frame 50 is inserted through the through hole 41c. That is, the housing 40 is fixed to the hub frame 50 at the fixing plate portion 41b. In addition, the motor unit 2 is fixed to the hub frame 50 at the housing 40.

In the present embodiment, a case where a plurality of fixing plate portions 41b are provided in the housing 40 is described. However, 1 flange-like fixing plate portion extending in the circumferential direction may be provided in the case 40. In this case, a plurality of through holes are provided in the flange-like fixing plate portion, and fixing screws are inserted into the plurality of through holes, respectively.

As shown in fig. 3, the 1 st floor 42 covers an opening on the inner side (the other side in the axial direction) of the tubular member 41 in the vehicle width direction. The 1 st bottom plate 42 is a circular plate extending in a direction perpendicular to the axial direction about the central axis J. The 1 st bottom plate 42 is provided with a bottom plate through hole 45 penetrating in the axial direction. The 1 st floor 42 has a 1 st surface 42a facing inward in the vehicle width direction and a 2 nd surface 42b facing outward in the vehicle width direction. The 2 nd surface 42b constitutes a part of the inner wall surface of the housing portion 49.

The 1 st surface 42a of the 1 st bottom plate 42 is provided with a pump accommodating recess 46 recessed in the axial direction. The bottom plate through hole 45 opens into the pump housing recess 46.

The 2 nd surface 42b of the 1 st bottom plate 42 is provided with a bearing holding recess 47 recessed in the axial direction. The bottom plate through hole 45 opens into the bearing holding recess 47. The bearing retaining recess 47 retains the bearing member 4, and the bearing member 4 rotatably supports the input shaft 12 of the motor unit 10.

The 1 st bottom plate 42 is provided with a resolver stator base portion 42c protruding in the axial direction on the 2 nd surface 42 b. That is, the housing 40 has a resolver stator base portion 42c. The resolver stator base portion 42c extends in the circumferential direction. The resolver stator 5a is screwed to the resolver stator mount 42c.

As shown in fig. 1, the 1 st oil passage 81 penetrating the inside is provided in the 1 st bottom plate 42. That is, the 1 st oil passage 81 is provided in the housing 40. The 1 st oil passage 81 extends upward from a lower region of the housing portion 49 of the housing 40. As described above, the oil O is stored in the storage portion 49. The oil O is stored in a lower region of the storage portion 49. The 1 st oil passage 81 introduces the oil O stored in the lower region of the storage portion 49 to the suction port 35 of the pump chamber 31. That is, the 1 st oil passage 81 connects the lower region of the housing portion 49 to the suction port 35.

As shown in fig. 3, the cover 44 is fixed to the 1 st surface 42a of the 1 st bottom plate 42. The cover 44 covers the opening of the pump housing recess 46 of the 1 st bottom plate 42. The pump chamber 31 of the pump unit 30 is formed in a space surrounded by the inner wall surface of the pump housing recess 46 and the cover unit 44. The pump chamber 31 is connected to the 1 st oil passage 81.

The 2 nd floor 43 covers an opening on the vehicle width direction outer side (one axial direction side) of the tubular member 41. The 2 nd bottom plate 43 is a circular plate extending in a direction perpendicular to the axial direction about the central axis J. The 2 nd base plate 43 is provided with a through-hole 48 penetrating in the axial direction. That is, the housing 40 is provided with a through-insertion hole 48 connecting the inside and outside of the housing 49. The output shaft 29 is inserted through the insertion hole 48.

The 2 nd floor 43 has a 1 st surface 43a facing the inside in the vehicle width direction and a 2 nd surface 43b facing the outside in the vehicle width direction. The 1 st surface 43a of the 2 nd bottom plate 43 constitutes an inner wall surface of the housing portion 49.

As shown in fig. 1, the 2 nd surface 43b of the 2 nd bottom plate 43 is axially opposed to the hub carrier 50. The 2 nd surface 43b is provided with a ridge 43c protruding in the axial direction. The convex portion 43c protrudes toward the hub carrier 50. The ridge 43c has an annular shape extending in the circumferential direction around the central axis J.

The ridge 43c has a 2 nd fitting surface 43j facing radially outward. That is, the housing 40 has the 2 nd fitting surface 43j. The 2 nd fitting surface 43j extends in the circumferential direction. The 2 nd fitting surface 43j is fitted to the 1 st fitting surface 53j provided on the hub carrier 50. Thereby, the housing 40 is positioned in a radial direction with respect to the hub carrier 50.

According to the present embodiment, the 1 st fitting surface 53j is fitted to the 2 nd fitting surface 43j, whereby the hub carrier 50 holds the motor unit 2 from the radially outer side. Therefore, the strength of fixing the motor unit 2 to the hub frame 50 can be improved. Further, according to the present embodiment, by fitting the 1 st fitting surface 53j and the 2 nd fitting surface 43j, the motor unit 2 can be easily aligned with respect to the hub frame 50, and the assembly process can be simplified.

As shown in fig. 3, the seal member 6 is located between the inner peripheral surface of the penetration hole 48 and the outer peripheral surface of the output shaft 29. The seal member 6 has a circular ring shape in plan view. The seal member 6 is fixed to the inner peripheral surface of the insertion hole 48 of the 2 nd base plate 43. The inner end of the seal member 6 is in contact with the outer peripheral surface of the output shaft 29. The sealing member 6 is made of an elastic material such as rubber or an elastomer resin. The seal member 6 suppresses leakage of the oil O in the storage portion 49 from the through-insertion hole 48 to the outside. The sealing member 6 also suppresses the intrusion of foreign matter into the housing 49 from the outside.

< Motor portion >)

The motor unit 10 includes a rotor 11 and an annular stator 17. The rotor 11 rotates around the central axis J. The stator 17 is located radially outward of the rotor 11.

The stator 17 is held by the inner peripheral surface of the tubular member 41 of the housing 40. The stator 17 is radially opposed to the rotor magnet 13a of the rotor 11. The stator 17 includes an annular stator core 19, a coil 18, and an insulating member not shown.

As shown in fig. 4, the stator core 19 has an annular core back 19a and a plurality of teeth 19b extending radially inward from the core back 19 a. The stator core 19 is formed by laminating laminated steel plates in the axial direction.

The plurality of teeth 19b are arranged in the circumferential direction. The stator 17 of the present embodiment has 72 teeth 19b. That is, the stator 17 of the present embodiment is 72 slots. The number of slots of the stator 17 is set according to the number of poles of the rotor magnet 13 a.

The coil 18 is wound around the tooth portion 19b via an insulating member. The insulating member (not shown) is made of resin and covers at least a part of the teeth 19b of the stator core 19. The insulation member insulates the teeth from the coil. A rotating magnetic field is generated in the stator 17 by a current flowing in the coil. In the present embodiment, the winding method of the coil 18 is not particularly limited, and concentrated winding, distributed winding, or other winding methods may be employed.

As shown in fig. 3, the coil 18 has a pair of coil ends 18a, 18b protruding axially to both sides with respect to the stator core 19. In the present embodiment, the coil end located on the inner side (the other side in the axial direction) in the vehicle width direction of the pair of coil ends 18a, 18b is referred to as the 1 st coil end 18a, and the coil end located on the outer side (the one side in the axial direction) in the vehicle width direction is referred to as the 2 nd coil end 18b.

The rotor 11 rotates around the central axis J. The rotor 11 includes an input shaft 12, a rotor holder 13, rotor magnets 13a, and a rotor core 13b.

The input shaft 12 extends along a central axis J. The input shaft 12 is provided with a sun gear 21 of a speed reducer section 20 on the outer peripheral surface midway in the axial direction. The input shaft 12 has a 1 st end 12a and a 2 nd end 12b located on both sides of the sun gear 21 in the axial direction.

The 1 st end 12a of the input shaft 12 is located outside (axially on one side) of the sun gear 21 in the vehicle width direction. The 1 st end 12a is accommodated in a recess (depression) 29a, and the recess (depression) 29a is provided in the output shaft 29.

The 2 nd end portion 12b of the input shaft 12 is located on the vehicle width direction inner side (the other axial side) with respect to the sun gear 21. The 2 nd end 12b is rotatably supported by the bearing member 4, and the bearing member 4 is held by the 1 st bottom plate 42. The 2 nd end 12b is supported by the housing 40 via the bearing member 4.

The input shaft 12 has a 1 st shaft 12A and a 2 nd shaft 12B. The 1 st axis 12A and the 2 nd axis 12B are connected to each other.

The 1 st shaft 12A is located on the 1 st end 12A side of the input shaft 12. The sun gear 21 is provided on the outer peripheral surface of the 1 st shaft 12A. The 2 nd shaft 12B is located on the 2 nd end 12B side of the input shaft 12. The input shaft 12 is supported by the bearing member 4 at the 2 nd shaft 12B.

The 1 st shaft 12A and the 2 nd shaft 12B are hollow shafts centered on the central axis J. The hollow portion of the 1 st shaft 12A and the hollow portion of the 2 nd shaft 12B are connected to each other. That is, the input shaft 12 is a hollow shaft centered on the central axis J. In other words, the input shaft 12 is provided with a hollow portion 12c extending in the axial direction and opening at both ends. As described in the subsequent stage, the hollow portion 12c functions as a 2 nd oil passage (an in-input-shaft oil passage) 82, and the 2 nd oil passage 82 is a part of the oil passage 80. That is, the 2 nd oil passage 82 extends in the axial direction inside the input shaft 12.

The 2 nd shaft 12B has a shaft flange portion 12d extending radially outward. The 2 nd shaft 12B is provided with a 3 rd oil passage (input shaft inner radial oil passage) 83 extending radially outward from the hollow portion 12c (i.e., the 2 nd oil passage 82).

The 3 rd oil passage 83 communicates the 2 nd oil passage 82 with the outside of the input shaft 12. A part of the oil O flowing through the 2 nd oil passage 82 flows into the 3 rd oil passage 83 by centrifugal force accompanying rotation of the rotor 11. The oil O flowing into the 3 rd oil passage 83 spreads radially outward from the radially outward opening of the 3 rd oil passage 83. The 3 rd oil passage 83 is located axially inward (axially on the other side) in the vehicle width direction than the axial position of the cylindrical portion 15 of the rotor holder 13. That is, the 3 rd oil passage 83 is located on the opposite side of the cylindrical portion 15 from the disc portion 14. Further, the radially outer opening of the 3 rd oil passage 83 is radially opposed to the 1 st coil end 18 a.

The rotor holder 13 holds the input shaft 12, the rotor core 13b, and the rotor magnet 13 a. The rotor holder 13 has a bottomed cylindrical shape and is open on the outer side (one axial side) in the vehicle width direction. The axial position of the opening of the rotor holder 13 overlaps with the axial position of the 2 nd coil end 18 b. That is, the axial position of the opening of the rotor holder 13 overlaps with the axial position of one coil end 18b of the pair of coil ends 18a, 18 b.

The rotor holder 13 includes: a disk portion 14 that expands in the radial direction; and a cylindrical portion 15 located at the radially outer end of the disk portion 14.

The cylindrical portion 15 has a cylindrical shape centered on the central axis J. The cylindrical portion 15 extends in the axial direction. A rotor core 13b and a rotor magnet 13a are fixed to the outer peripheral surface of the cylindrical portion 15. The rotor magnet 13a is fixed to the outer peripheral surface of the cylindrical portion 15 via the rotor core 13 b.

The circular plate portion 14 is located at an opening on the inner side (the other side in the axial direction) of the tubular portion 15 in the vehicle width direction. The circular plate portion 14 closes an opening on the inner side (the other side in the axial direction) of the tubular portion 15 in the vehicle width direction. The disk portion 14 has a disk shape centered on the central axis J. The disk portion 14 has a 1 st surface 14a facing the inside in the vehicle width direction and a 2 nd surface (bottom surface) 14b facing the outside in the vehicle width direction. The 2 nd surface 14b is axially opposed to the planetary gear 22.

A fixing hole 14h is provided in the center of the disk portion 14 in plan view. The outer peripheral surface of the 2 nd shaft 12B of the input shaft 12 is fitted into the fixing hole 14h. That is, the rotor holder 13 is fixed to the input shaft 12 at the disk portion 14. The shaft flange 12d of the input shaft 12 is in contact with the 2 nd surface 14b. Thereby, the input shaft 12 is aligned in the axial direction with respect to the disk portion 14. The rotor holder 13 and the input shaft 12 may be indirectly fixed via other members.

The 1 st surface 14a of the disk portion 14 is provided with a resolver support portion 14c protruding in the axial direction. That is, the disk portion 14 has a resolver support portion 14c. The resolver support portion 14c protrudes inward in the vehicle width direction (axially on the other side). The resolver support portion 14c extends in the circumferential direction. That is, the resolver support portion 14c has a cylindrical shape centered on the central axis J. A resolver rotor 5b is fixed to the tip of the resolver support portion 14c. The resolver rotor 5b is radially opposed to the resolver stator 5 a. The resolver rotor 5b and the resolver stator 5a constitute a resolver 5. The resolver 5 detects the rotation angle of the rotor 11 with respect to the housing 40.

According to the present embodiment, the disk portion 14 is provided with the resolver support portion 14c protruding in the axial direction and extending in the circumferential direction, whereby the rigidity of the disk portion 14 can be improved. When the disk portion 14 is deformed, the cylindrical portion 15 is displaced, and there is a possibility that a gap between the rotor magnet 13a and the stator 17 may be deviated. According to the present embodiment, by suppressing the deformation of the disk portion 14, the displacement of the cylindrical portion 15 can be suppressed, and the rotation efficiency of the motor portion 10 can be sufficiently ensured.

The rotor core 13b is press-fitted and fixed to the cylindrical portion 15 of the rotor holder 13. The rotor core 13b is formed by laminating laminated steel plates in the axial direction. The rotor core 13b is provided with a plurality of holding holes 13c for holding the rotor magnets 13 a.

As shown in fig. 4, the rotor magnet 13a is radially opposed to the stator 17. The rotor magnet 13a is held by the rotor core 13 b. The rotor magnet 13a is fixed to the outer peripheral surface of the cylindrical portion 15 via the rotor core 13 b.

In the present embodiment, the rotor magnet 13a is composed of 12 sector magnets 13aa. That is, the rotor magnet 13a has 12 sector magnets 13aa. In the present embodiment, the rotor magnet 13a has 12 poles. The rotor magnet 13a may be an annular ring magnet.

The number of poles of the rotor magnet 13a is preferably 10 poles or more. By setting the number of poles of the rotor magnet 13a to 10 or more, the circumferential dimension of each sector magnet 13aa corresponding to each pole is reduced, and the magnetic force of each sector magnet 13aa is reduced. As a result, the radial dimension of the rotor core 13b can be reduced. This can reduce the weight of the in-wheel motor 1. In addition, by reducing the radial dimension of the rotor core 13b, the inner diameter of the cylindrical portion 15 can be enlarged. The rotor holder 13 of the present embodiment houses the speed reducer section 20 inside the cylindrical section 15. Accordingly, the degree of freedom in the number of teeth of each gear (sun gear 21, planetary gear 22, and ring gear 23) constituting the speed reducer section 20 is increased, and a more preferable reduction ratio can be realized. More specifically, the diameter of the planetary gear 22 is increased, and the number of teeth of the planetary gear 22 can be increased, so that the reduction ratio of the speed reducer section 20 can be increased.

In addition, according to the present embodiment, by setting the number of poles of the rotor magnet 13a to 10 poles or more, the magnetic flux density passing through the stator core 19 is reduced. Therefore, the radial dimension of the stator core 19 can be reduced. Therefore, downsizing and weight saving of the radial dimension of the motor unit 2 can be achieved without reducing the output.

< bearing Member >)

As shown in fig. 3, the bearing member 4 rotatably supports the input shaft 12. In the present embodiment, the bearing member 4 is a ball bearing. The inner race of the bearing member 4 is fixed to the input shaft 12. The outer ring of the bearing member 4 is fixed to a bearing holding recess 47 provided in the housing 40. The bearing member 4 supports the input shaft 12 at a position on the inner side (the other side in the axial direction) in the vehicle width direction than the coupling portion between the input shaft 12 and the rotor holder 13.

The kind of the bearing member 4 is not limited. For example, a sliding bearing made of a sintered material may be used as the bearing member 4. In this case, the bearing is fixed to either one of the input shaft 12 and the housing 40. In the case where a material having high wear resistance is used as the housing 40 (more specifically, the 1 st bottom plate 42), the housing 40 itself may be used as a bearing for the housing 40.

< speed reducer section >)

The decelerator unit 20 is connected to the rotor 11 of the motor unit 10, and decelerates the rotation of the rotor 11. The speed reducer section 20 includes a sun gear 21, a plurality of planetary gears 22, a plurality of carrier pins 24, a ring gear 23, and an output shaft 29. The sun gear 21, the planetary gear 22, the ring gear 23, the carrier pin 24, and the output shaft 29 constitute a planetary gear mechanism.

According to the present embodiment, since the speed reducer section 20 constitutes a planetary gear mechanism, the input shaft 12 to which power is input and the output shaft 29 from which power is output can be coaxially arranged. This can miniaturize the motor unit 2.

In the present embodiment, the sun gear 21, the planetary gears 22, and the ring gear 23 are helical gears (helical gears). Therefore, when the speed reducer section 20 is operated, the sun gear 21, the planetary gears 22, and the ring gear 23 are subjected to stress in the axial direction from the gears that mesh with each other, respectively. The axial stress to which the sun gear 21 and the ring gear 23 are subjected is in the opposite direction to the axial stress to which the planetary gears 22 are subjected. In the present embodiment, when the vehicle is driven forward, the sun gear 21 and the ring gear 23 receive stress from the planetary gear 22 toward the vehicle width direction inner side (the other side in the axial direction), and the planetary gear 22 receives stress from the sun gear 21 and the ring gear 23 toward the vehicle width direction outer side (the one side in the axial direction). In addition, when the vehicle is caused to reverse, each gear receives stress in a direction opposite to that in the case of forward movement.

The sun gear 21 is provided on the outer peripheral surface of the input shaft 12 of the rotor 11. That is, the sun gear 21 is fixed to the rotor 11. The sun gear 21 rotates together with the input shaft 12.

In the present embodiment, the sun gear 21 is provided by machining teeth on the outer peripheral surface of the 1 st shaft 12A. That is, in the present embodiment, the sun gear 21 and the 1 st shaft 12A are one member. However, the sun gear 21 may be provided on the outer periphery of the input shaft 12, or may be provided on the outer periphery of the input shaft 12 by pressing a pinion gear that is a separate member into the input shaft 12.

The plurality of planetary gears 22 are arranged radially outward of the sun gear 21. The planetary gear 22 rotates in mesh with the sun gear 21. The planetary gear 22 rotates about the rotation axis Jp. In addition, the planetary gear 22 revolves around the sun gear 21. The speed reducer section 20 of the present embodiment is provided with 3 planetary gears 22. The 3 planetary gears 22 are arranged at equal intervals in the circumferential direction. The number of the planetary gears 22 is not limited as long as a plurality of planetary gears 22 are provided in the speed reducer section 20.

A gear center hole 22a extending in the axial direction is provided in the center of the planetary gear 22. A carrier pin 24 is inserted into the gear center hole 22a. The planetary gear 22 rotates about the carrier pin 24.

Generally, a step gear is sometimes used as a planetary gear of the planetary gear mechanism. Such a step gear has two stages of gears arranged in the axial direction and coaxially arranged. The gears of the two stages are fixed with each other. The step gear meshes with the sun gear at one of the two stages of gears and with the ring gear at the other stage of gears.

In contrast, the planetary gear 22 of the present embodiment is not a stepped gear. The planetary gear 22 meshes with the sun gear 21 and the ring gear 23 at 1 gear. Therefore, the sun gear 21, the planetary gears 22, and the ring gear 23 overlap each other in the axial direction. By adopting such a structure, the axial dimension of the speed reducer section 20 can be reduced.

The carrier pin 24 rotatably supports the planetary gear 22. The carrier pin 24 revolves around the sun gear 21 together with the planetary gears 22. A bearing member (3 rd bearing member) 22b is disposed between the outer peripheral surface of the carrier pin 24 and the inner peripheral surface of the gear center hole 22a of the planetary gear 22.

In the present embodiment, the bearing member 22b provided in the gear center hole 22a is a so-called roller cage assembly (cage and roller). However, the type of the bearing member 22b is not limited thereto, and the bearing member 22b may be a needle bearing, for example.

The wheel carrier pin 24 is provided with a 1 st pin oil passage 85, a plurality of 2 nd pin oil passages 86, and a 3 rd pin oil passage 87.

The 1 st pin inner oil passage 85 extends in the axial direction inside the wheel carrier pin 24. The 1 st pin inner oil passage 85 opens at an end face of the wheel carrier pin 24 on the vehicle width direction outer side (axial direction side). The 1 st pin oil passage 85 may be opened on the inner side (the other axial side) of the wheel carrier pin 24 in the vehicle width direction. That is, the 1 st pin oil passage 85 may extend in the axial direction inside the wheel carrier pin 24 and may be opened on at least one side in the axial direction.

The 2 nd pin oil passage 86 extends radially outward of the rotation axis Jp from the 1 st pin oil passage 85. The 2 nd pin oil passage 86 communicates the 1 st pin oil passage 85 with the outside of the truck pin 24. The 2 nd pin inner oil passage 86 axially overlaps the planetary gear 22. Therefore, the 2 nd pin oil passage 86 opens inside the gear center hole 22 a. In the present embodiment, the 4 2 nd in-pin oil passages 86 are provided in the wheel carrier pin 24. The 4 2 nd pin oil passages 86 are arranged at equal intervals in the circumferential direction of the rotation axis Jp.

The 3 rd pin oil passage 87 extends radially inward from the 1 st pin oil passage 85. The 3 rd pin oil passage 87 communicates the 1 st pin oil passage 85 with the outside of the truck pin 24. The 3 rd pin oil passage 87 is located outside (axially one side) the 2 nd pin oil passage 86 in the vehicle width direction. The 3 rd pin internal oil passage 87 opens in the 1 st pin holding hole 25a of the carrier 25 provided in the output shaft 29.

The output shaft 29 supports the wheel carrier pin 24. The output shaft 29 rotates around the center axis J with the revolution of the planetary gear 22 and the carrier pin 24. The output shaft 29 is rotatably supported by the hub bearing 60.

The output shaft 29 has: a cylindrical output shaft main body portion 29A extending in the axial direction about the central axis J; and a wheel frame (flange portion) 25. The carrier 25 extends radially outward in a flange shape with respect to the output shaft main body 29A. In the present embodiment, the output shaft main body 29A and the carrier 25 are one member. However, the output shaft main body 29A and the carrier 25 may be separate members coupled to each other.

The wheel carrier 25 has a disk shape centered on the central axis J. The wheel carrier 25 is located at an end portion of the output shaft main body portion 29A on the vehicle width direction inner side (the other axial side). The carrier 25 is located on the vehicle width direction outer side (axial direction side) with respect to the plurality of planetary gears 22. An end surface of the carrier 25 facing the vehicle width direction inner side is axially opposed to the plurality of planetary gears 22.

The wheel carrier 25 is provided with a plurality (3 in the present embodiment) of 1 st pin holding holes (pin holding holes) 25a penetrating in the axial direction. The plurality of 1 st pin retaining holes 25a are arranged at equal intervals in the circumferential direction. A wheel carrier pin 24 is inserted into the 1 st pin holding hole 25a. Thereby, the wheel carrier 25 holds the plurality of wheel carrier pins 24. The wheel carrier pin 24 is fitted into the 1 st pin holding hole 25a. Accordingly, the wheel carrier pin 24 is fixed to the wheel carrier 25 and does not rotate relative to the wheel carrier 25.

A wheel frame cover 26 is fixed to the wheel frame 25. The wheel carrier cover 26 is located on the inner side (the other axial side) in the vehicle width direction with respect to the wheel carrier 25. The wheel carrier cover 26 includes a cover main body 26a and a fixing portion 26b protruding from the cover main body 26a toward the wheel carrier 25.

The cover main body 26a has a disk shape centered on the central axis J. The planetary gear 22 is disposed between the carrier 25 and the cover main body 26a in the axial direction. When viewed from the axial direction, the planetary gear 22 partially protrudes radially outward from the carrier 25 and the cover main body portion 26 a.

A plurality (3 in the present embodiment) of 2 nd pin holding holes 26c penetrating in the axial direction are provided in the cap body portion 26 a. The 2 nd pin retaining hole 26c is inserted with the wheel carrier pin 24. The wheel carrier pin 24 is fitted into the 2 nd pin holding hole 26c. Therefore, both ends of the wheel carrier pin 24 are supported by the wheel carrier 25 and the wheel carrier cover 26.

The fixing portion 26b extends outward (axially on one side) in the vehicle width direction from the radially outer edge of the cover main body portion 26 a. The fixing portion 26b is fixed to the wheel frame 25 at the front end portion. That is, the wheel frame cover 26 is fixed to the wheel frame 25 at the fixing portion 26b. The fixed portion 26b extends between the planetary gears 22 in the circumferential direction. In the present embodiment, 3 fixing portions 26b are provided in the wheel carrier cover 26.

In the axial direction, the 1 st thrust washer 22c is interposed between the carrier 25 and the planetary gear 22 and between the cover main body portion 26a and the planetary gear 22, respectively. When the speed reducer section 20 is operated, the planetary gear 22 applies stress in any axial direction from the sun gear 21 and the ring gear 23. By providing the 1 st thrust washer 22c, the rotation of the planetary gear 22 can be smoothed, and the wear of the side surface of the planetary gear 22 can be suppressed.

A recess 29a is provided in an end surface of the wheel frame 25 facing the vehicle width direction inner side (the other side in the axial direction). That is, the wheel carrier 25 is provided with a recess 29a that opens in the axial direction.

The recess 29a extends along the central axis J. The concave portion 29a is circular with the central axis J as a center in a plan view. The 1 st end 12a of the input shaft 12 is accommodated in the recess 29a.

The 2 nd thrust washer 29c is interposed between the bottom surface of the recess 29a and the 1 st end 12a of the input shaft 12. When the input shaft 12 rotates in a predetermined direction, the sun gear 21 receives stress on one side in the axial direction from the planetary gears 22. Accordingly, the 1 st end 12a of the input shaft 12 is pressed against the bottom surface of the recess 29a. According to the present embodiment, by providing the 2 nd thrust washer 29c, the rotation of the input shaft 12 can be smoothed, and the abrasion of the end face of the 1 st end portion 12a of the input shaft 12 can be suppressed.

A plurality of grooves 29b are provided on the inner peripheral surface of the recess 29 a. The groove portion 29b extends from the bottom surface of the recess 29a to the opening in the axial direction. The plurality of groove portions 29b are arranged at equal intervals in the circumferential direction.

The carrier 25 is provided with an in-carrier oil passage 84 extending radially outward from the recess 29 a. The truck internal oil passage 84 opens to the groove 29b at the inner peripheral surface of the recess 29 a. The wheel carrier oil passage 84 opens to the inner peripheral surface of the 1 st pin holding hole 25 a.

The in-wheel carrier oil passage 84 is connected to a 3 rd pin oil passage 87 provided in the wheel carrier pin 24. The in-wheel carrier oil passage 84 is connected to the 1 st in-pin oil passage 85 via the 3 rd in-pin oil passage 87. That is, the 3 rd pin oil passage 87 communicates the 1 st pin oil passage 85 with the truck oil passage 84.

The ring gear 23 is disposed radially outward of the plurality of planetary gears 22. The ring gear 23 surrounds the plurality of planetary gears 22 from the radially outer side. The ring gear 23 meshes with the plurality of planetary gears 22. That is, the planetary gear 22 meshes with the sun gear 21 on the radial inner side and meshes with the ring gear 23 on the radial outer side.

The ring gear 23 has a ring gear main body portion 23a, a ring gear cylindrical portion 23b, and a ring gear flange portion 23c. The ring gear main body portion 23a has an annular shape. The tooth surface of the gear is provided on the inner peripheral surface of the ring gear main body portion 23 a. The ring gear main body portion 23a has an annular shape. The ring gear cylindrical portion 23b extends outward (axially one side) in the vehicle width direction from the ring gear main body portion 23 a. The ring gear flange portion 23c extends radially outward from an end portion of the ring gear cylindrical portion 23b that is outward in the vehicle width direction (one axial direction).

As shown in fig. 1, the ring gear tubular portion 23b is provided with a ring gear through hole 23d located below the center axis J. That is, the ring gear 23 is provided with a ring gear through hole 23d. The ring gear through hole 23d penetrates in the radial direction. Preferably, the ring gear through hole 23d overlaps with the central axis J when viewed from the up-down direction.

As shown in fig. 3, the ring gear 23 is fixed to the 2 nd base plate 43 of the housing 40 at the ring gear flange portion 23 c. Therefore, when the sun gear 21 rotates, the planetary gears 22 rotate while revolving around the sun gear 21. The carrier 25 rotates around the center axis J with the revolution of the planetary gear 22. The wheel carrier 25 is fixed to the wheel 3 via an output shaft main body 29A. Thus, the rotation of the wheel carrier 25 is transmitted to the wheel 3.

According to the present embodiment, the ring gear 23 has the ring gear flange portion 23c, and therefore the rigidity is improved. This makes it possible to reduce the thickness of the ring gear main body portion 23a in the radial direction, and to reduce the weight of the motor unit 2.

In the present embodiment, at least a part of the sun gear 21, the planetary gears 22, and the ring gear 23 is housed inside the cylindrical portion 15 of the rotor holder 13 in the radial direction. Therefore, the axial dimension of the motor unit 2 can be reduced. In addition, the in-wheel motor 1 can be made thinner in the axial direction.

< Pump section >)

The pump section 30 is provided in the center of the 1 st floor 42. The pump unit 30 is disposed on the vehicle width direction inner side (the other axial side) of the input shaft 12.

The pump unit 30 includes a pump chamber 31, a coupling member 34, an external gear (inner rotor) 32, an internal gear (outer rotor) 33, a suction port 35, and a pump outlet 36.

The pump chamber 31 is configured as a space surrounded by an inner wall surface of a pump housing recess 46 provided on the 1 st surface 42a of the 1 st bottom plate 42 and a cover 44 covering an opening of the pump housing recess 46. An O-ring 44a is provided between the cover 44 and the 1 st surface 42a of the 1 st bottom plate 42. Thereby, the pump chamber 31 is sealed from the outside. The pump chamber 31 houses an external gear 32 and an internal gear 33. The pump chamber 31 passes through the center axis J. The outer shape of the pump chamber 31 is circular when viewed from the axial direction.

The coupling member 34 has a cylindrical shape extending in the axial direction about the central axis J. That is, the coupling member 34 is provided with a hollow portion 34a extending along the central axis J. The coupling member 34 is disposed in the bottom plate through hole 45 of the housing 40.

The coupling member 34 couples the input shaft 12 and the external gear 32. One end of the coupling member 34 is fitted to the 2 nd shaft 12B of the input shaft 12 on the outer peripheral surface. The other end of the coupling member 34 is fitted into the external gear center hole 32a of the external gear 32 on the outer peripheral surface. The hollow portion 34a of the coupling member 34 communicates with the hollow portion 12c provided in the input shaft 12. The hollow portion 34a of the coupling member 34 constitutes a part of the 2 nd oil passage 82.

The external gear 32 is fixed to the 2 nd end 12b of the input shaft 12 via a coupling member 34. The external gear 32 rotates around the center axis J together with the input shaft 12.

Fig. 5 is a cross-sectional view of the pump portion 30 in a cross-section perpendicular to the center axis J. The external gear 32 is housed in the pump chamber 31. The external gear 32 has a plurality of teeth 32b on the outer peripheral surface. The tooth profile of the tooth portion 32b of the external gear 32 is a trochoid tooth profile.

The internal gear 33 surrounds the radially outer side of the external gear 32. The internal gear 33 is an annular gear rotatable about a rotation axis Jt eccentric to the central axis J. The internal gear 33 is housed in the pump chamber 31. The internal gear 33 meshes with the external gear 32. The internal gear 33 has a plurality of teeth 33b on the inner peripheral surface. The tooth profile of the tooth portion 33b of the internal gear 33 is a trochoid tooth profile.

According to the present embodiment, the tooth profile of the tooth portion 32b of the external gear 32 and the tooth profile of the tooth portion 33b of the internal gear 33 are trochoid tooth profiles, and thus a trochoid pump can be constituted. Therefore, noise generated from the pump unit 30 can be reduced, and the pressure and amount of the oil O discharged from the pump unit 30 can be easily stabilized.

The 1 st pump-in oil passage 38 and the 2 nd pump-in oil passage 39 are provided on the inner wall surface of the pump chamber 31. The 1 st pump-in oil passage 38 is an oil passage provided in a groove portion of a bottom surface of the pump housing recess 46 and a facing surface of the cover portion facing the bottom surface. Similarly, the 2 nd pump-in oil passage 39 is an oil passage provided in a groove portion of a bottom surface of the pump housing recess 46 and an opposing surface of the cover portion opposing the bottom surface. The 1 st pump internal oil passage 38 and the 2 nd pump internal oil passage 39 extend in an arc shape in the circumferential direction. The 1 st pump-in oil passage 38 and the 2 nd pump-in oil passage 39 are arranged in the circumferential direction. The 1 st pump-in oil passage 38 and the 2 nd pump-in oil passage 39 overlap with the tooth portion 33b of a part of the internal gear 33 when viewed from the axial direction.

The 1 st pump internal oil passage 38 is connected to the 1 st oil passage 81. The 2 nd pump-in oil passage 39 is connected to the hollow portion 34a of the coupling member 34. That is, the 2 nd pump-in oil passage 39 is connected to the 2 nd oil passage 82.

The suction port 35 is provided at the boundary between the 1 st pump oil passage 38 and the 1 st oil passage 81. The suction port 35 sucks the oil O into the pump chamber 31 from the lower region of the housing portion 49 through the 1 st oil passage 81.

The pump outlet 36 is provided at the boundary between the 2 nd pump internal oil passage 39 and the 2 nd oil passage 82. The pump outlet 36 discharges the oil O from the pump chamber 31. That is, the 2 nd oil passage 82 is connected to the pump outlet 36.

When the input shaft 12 rotates, the external gear 32 fixed to the input shaft 12 rotates around the center axis J. Thereby, the internal gear 33 engaged with the external gear 32 rotates about the rotation axis Jt. In addition, a portion where a gap between the external gear 32 and the internal gear 33 becomes wider moves around the center axis J. The oil O sucked into the pump chamber 31 from the suction port 35 is delivered to the pump outlet 36 through the gap between the external gear 32 and the internal gear 33. The oil O discharged from the pump outlet 36 flows into the 2 nd oil passage 82. Thus, the pump unit 30 is driven via the input shaft 12.

According to the present embodiment, the pump unit 30 is driven by the rotation of the input shaft 12, and the oil O is sucked from the lower region of the housing unit 49 and circulated in the oil passage 80. Therefore, no external power source is required to drive the pump section 30. Further, by circulating the oil O in the housing portion 49, the lubricity of each gear of the speed reducer portion 20 can be improved, and the motor portion 10 can be cooled by the oil O.

According to the present embodiment, the pump outlet 36 of the pump section 30 is connected to the 2 nd oil passage 82 in the input shaft 12. Since the input shaft 12 rotates around the center axis J, the oil O discharged from the 2 nd oil passage 82 is scattered radially outward by the centrifugal force of the input shaft 12. Therefore, the inside of the 2 nd oil passage 82 is negative pressure, and as a result, the suction of the oil O by the pump portion 30 is promoted. Therefore, even when the pump unit 30 is miniaturized, the pump unit 30 can have a sufficient suction force. According to the present embodiment, the pump unit 30 can be miniaturized, and the motor unit 2 can be miniaturized.

< oil way >)

Next, the oil passage 80 for circulating the oil O in the housing portion 49 of the housing 40 will be described.

The oil passages 80 include a 1 st oil passage 81, a 2 nd oil passage 82, a 3 rd oil passage 83, a truck oil passage 84, a 1 st pin oil passage 85, a 2 nd pin oil passage 86, and a 3 rd pin oil passage 87.

When the in-wheel motor 1 is stopped, the oil O is accumulated in the lower region of the housing portion 49. As shown in fig. 1, the upper limit of the level of the oil O in the lower region of the housing portion 49 is preferably lower than the lower end portion of the rotor 11. This can suppress the oil O from becoming resistance to the rotation of the rotor 11. The 1 st oil passage 81 is located below the lower limit of the liquid level of the oil O with respect to the opening of the housing portion 49.

When the in-wheel motor 1 is driven, the pump section 30 is driven with the rotation of the input shaft 12. When the pump unit 30 is driven, the oil O stored in the lower region of the storage unit 49 moves from the suction port 35 into the pump chamber 31 through the 1 st oil passage 81. The oil O in the pump chamber 31 moves from the pump outlet 36 to the 2 nd oil passage 82.

A part of the oil O in the 2 nd oil passage 82 flows into the 3 rd oil passage 83 by centrifugal force based on the rotation of the input shaft 12. Further, a part of the oil O in the 2 nd oil passage 82 reaches an end portion of the 2 nd oil passage 82 on the vehicle width direction outer side (axial direction side).

The oil O flowing into the 3 rd oil passage 83 moves radially outward in the 3 rd oil passage 83 by centrifugal force. The oil O reaching the radially outer side of the 3 rd oil passage 83 is scattered radially outward from the outer peripheral surface of the input shaft 12.

According to the present embodiment, by providing the 3 rd oil passage 83 in the input shaft 12, the oil O can be scattered from the 3 rd oil passage 83 into the housing 49 by the centrifugal force of the input shaft 12. This can improve the lubricity of each portion in the housing portion 49 and can cool the motor portion 10 with the oil O.

The 3 rd oil passage 83 overlaps the axial position of one coil end (the 1 st coil end 18a in the present embodiment) of the pair of coil ends 18a, 18 b. That is, the radially outer opening of the 3 rd oil passage 83 is radially opposed to the 1 st coil end 18 a. The oil O scattered radially outward from the 3 rd oil passage 83 reaches the 1 st coil end 18a, and cools the 1 st coil end 18 a.

In the present embodiment, the resolver support portion 14c of the rotor holder 13 is located between the 1 st coil end 18a and the radially outer opening of the 3 rd oil passage 83. Therefore, the oil O scattered from the 3 rd oil passage 83 reaches the 1 st coil end 18a after being transferred to the surface of the resolver support portion 14 c.

In addition, a part of the oil O diffused from the opening of the 3 rd oil passage 83 is supplied to the bearing member 4. The oil O supplied to the bearing member 4 promotes lubrication of the bearing member 4, suppressing wear of the bearing member 4.

The 2 nd oil passage 82 opens at the 1 st end 12a of the input shaft 12. Therefore, the oil O of the 2 nd oil passage 82 flows out from the 2 nd oil passage 82 at the 1 st end portion 12a of the input shaft 12. The 1 st end 12a of the input shaft 12 is received in a recess 29a provided in the output shaft 29. Therefore, the 2 nd oil passage 82 opens inside the recess 29a. The oil O flows from the 2 nd oil passage 82 into the recess 29a.

The oil O flowing into the recess 29a is supplied to the 2 nd thrust washer 29c accommodated in the recess 29a. This improves the lubricity between the 2 nd thrust washer 29c and the end surface of the input shaft 12, and can make the rotation of the input shaft 12 smoother.

The oil O flowing into the concave portion 29a is applied with a centrifugal force accompanying rotation of the output shaft 29 about the center axis J. Thus, the oil O is concentrated in the plurality of groove portions 29b provided on the inner peripheral surface of the concave portion 29a. The oil O flows into the wheel carrier oil passage 84 that opens in the groove 29 b.

According to the present embodiment, the groove 29b is provided on the inner peripheral surface of the recess 29a, and the in-wheel carrier oil passage 84 opens into the groove 29 b. This allows the oil O in the recess 29a to be smoothly introduced into the in-carrier oil passage 84.

In addition, a part of the oil O flowing into the concave portion 29a moves in the axial direction, and flows out from the opening of the concave portion 29 a. A part of the oil O flowing out from the opening of the concave portion 29a flows radially outward and flows into the gap between the carrier 25 and the planetary gear 22. The oil O flowing into the gap between the carrier 25 and the pinion 22 improves the lubricity of the 2 nd thrust washer 29c interposed between the carrier 25 and the pinion 22.

The oil O flowing into the carrier oil passage 84 flows radially outward by the centrifugal force of the output shaft 29, and flows into the 1 st pin oil passage 85 through the 3 rd pin oil passage 87.

According to the present embodiment, the in-wheel carrier oil passage 84 and the 3 rd pin oil passage 87 extend in the radial direction. Therefore, the oil O can be smoothly introduced from the recess 29a into the 1 st pin oil passage 85 by the centrifugal force accompanying the rotation of the output shaft 29.

Part of the oil O flowing into the 1 st pin oil passage 85 is guided to the outer peripheral surface of the wheel carrier pin 24 through the 2 nd pin oil passage 86. A bearing member 22b is disposed between the outer peripheral surface of the carrier pin 24 and the inner peripheral surface of the gear center hole 22 a. According to the present embodiment, the oil O is supplied to the bearing member 22b, and the lubricity of the bearing member 22b can be improved. The oil O guided to the outer peripheral surface of the carrier pin 24 flows along the end surface of the planetary gear 22 and is supplied to the 2 nd thrust washer 29 c. According to the present embodiment, the lubricity of the 2 nd thrust washer 29c can be improved. The oil O flows radially outward and is supplied to tooth surfaces of the planetary gear 22 and the ring gear 23.

Part of the oil O flowing into the 1 st pin oil passage 85 flows out of the 1 st pin oil passage 85 at the opening in the axial direction of the 1 st pin oil passage 85, and is scattered radially outward. A ring gear 23 is disposed radially outward of the carrier pin 24. Therefore, the oil O scattered from the 1 st pin oil passage 85 reaches the tooth surface of the ring gear 23. The tooth surfaces of the ring gear 23 are in contact with the tooth surfaces of the planetary gears 22. In addition, the tooth surfaces of the planetary gears 22 are in contact with the tooth surfaces of the sun gear 21. Therefore, the oil O reaching the tooth surface of the ring gear 23 can improve not only the lubricity of the engagement of the ring gear 23 with the pinion gears 22, but also the lubricity of the engagement of the pinion gears 22 with the sun gear 21. This can improve the transmission efficiency of the sun gear 21, the planetary gears 22, and the ring gear 23. Further, wear of the sun gear 21, the planetary gears 22, and the ring gear 23 can be suppressed.

The oil O reaching the ring gear 23 is accumulated in the radially inner lower region of the ring gear 23. As shown in fig. 1, the ring gear 23 is provided with a ring gear through hole 23d located below the center axis J. The oil O accumulated in the lower region on the inner side in the radial direction of the ring gear 23 moves to the lower region of the housing 49 provided in the case 40 via the ring gear through hole 23d. According to the present embodiment, by providing the ring gear through hole 23d, circulation of the oil O in the housing portion 49 can be promoted, and the oil O can be effectively utilized.

Preferably, the ring gear through hole 23d overlaps with the central axis J when viewed from the up-down direction. The ring gear 23 extends circumferentially around the center axis J. Therefore, the lowest point of the inner peripheral surface of the ring gear 23 is located directly below the central axis J. By disposing the ring gear through-hole 23d so as to overlap the central axis J when viewed from the up-down direction, the ring gear through-hole 23d can be located at the lowest point of the inner peripheral surface of the ring gear 23. This effectively discharges the oil O radially inward of the ring gear 23.

As shown in fig. 3, the cylindrical portion 15 of the rotor holder 13 is located radially outward of the planetary gear 22. Therefore, a part of the oil O scattered radially outward of the planetary gear 22 via the 1 st pin inner oil passage 85 is caught by the inner peripheral surface of the cylindrical portion 15. The oil O trapped by the inner peripheral surface of the cylindrical portion 15 is scattered radially outward from the opening of the rotor holder 13 by the centrifugal force of the rotor holder 13. In the present embodiment, the axial position of the opening of the rotor holder 13 overlaps the axial position of the 2 nd coil end 18 b. Therefore, the oil O scattered from the opening of the rotor holder 13 reaches the 2 nd coil end 18b, and cools the 2 nd coil end 18 b.

The oil reaching the 1 st coil end 18a and the 2 nd coil end 18b moves downward by gravity. Thereby, the oil O is again collected in the lower region of the storage portion 49.

< brake section >)

As shown in fig. 2, the brake portion 70 has a brake caliper 71 and a disc rotor 72. The brake unit 70 brakes the rotation of the wheel 3.

The disc rotor 72 has a disc main body portion 72a and a bracket portion 72b. The disk main body 72a and the bracket 72b are fixed to each other by a fixing screw 72 c.

The disk main body 72a has a circular annular plate shape centered on the central axis J. The hub carrier 50 is disposed radially inward of the disk main body 72 a. A through hole 72e through which the fixing screw 72c is inserted is provided at the radially inner end of the disk main body 72 a.

The bracket portion 72b has a circular annular plate shape centered on the central axis J. The bracket portion 72b has a conical shape that is inclined inward in the vehicle width direction (axially on the other side) as going outward in the radial direction. A screw hole 72f to which the fixing screw 72c is fastened is provided at the radially outer end portion of the bracket portion 72b.

A through hole 72d extending in the axial direction is provided at the radially inner end portion of the bracket portion 72b. A fixing screw 69 is inserted through the through hole 72d, and the fixing screw 69 fixes the bracket 72b, the inner ring 62 of the hub bearing 60, and the wheel 3 to each other. That is, the disc rotor 72 is fixed to the inner ring 62 of the hub bearing 60 and the wheel 3 at the bracket portion 72b. Thus, the disc rotor 72 rotates around the center axis J together with the wheel 3.

The brake caliper 71 includes a caliper body portion 71a and a pair of brake pads 71b. The pair of brake pads 71b are detachably held by the caliper body 71a.

The caliper body portion 71a is disposed on the vehicle front side or the vehicle rear side with respect to the center axis J. The caliper body portion 71a is fixed to the hub frame 50 by screws, not shown. That is, the brake caliper 71 is fixed to the hub frame 50 at the brake caliper body portion 71a. A slit 71c extending in the circumferential direction is provided in the brake caliper body portion 71a. The slit 71c opens radially inward. A disk main body 72a of the disk rotor 72 is disposed in the slit 71c.

A pair of brake pads 71b are fixed to the inner wall surface of the slit 71c. The pair of brake pads 71b are axially opposed to each other through the disc main body portion 72a.

The brake pad 71b is pushed out by the caliper body portion 71a in a direction approaching the disc body portion 72a. Thereby, the brake pad 71b contacts the surface of the disc main body 72a in the axial direction, and brakes the disc main body 72a. That is, the pair of brake pads 71b sandwich the disc rotor 72.

In fig. 2, for ease of understanding, the axial gap between the disc main body 72a and the brake pad 71b is enlarged.

In the present embodiment, the disc rotor 72 is located on the axially opposite side of the motor unit 2 with respect to the hub carrier 50. That is, the hub carrier 50 is axially located between the disc rotor 72 and the motor unit 2.

< wheel >

The wheel 3 has a rim portion 3a, a disc portion 3b, and a fixing portion 3c.

The wheel 3 is connected to an output shaft 29 of the reducer section 20.

The rotation of the rotor 11 of the motor section 10 is transmitted to the wheel 3 via the decelerator section 20. The wheel 3 holds a tire, not shown, at a rim portion 3 a. The wheel 3 transmits power to the road surface via the tire.

The rim portion 3a has a cylindrical shape centered on the center axis J. The motor unit 2, the hub carrier 50, the hub bearing 60, and the brake portion 70 are disposed radially inward of the rim portion 3 a. More specifically, the hub carrier 50 and the hub bearing 60 are disposed entirely radially inward of the rim portion 3 a. That is, the hub frame 50 and the hub bearing 60 are integrally located inside the wheel 3.

The outer end portion (one side in the axial direction) of the motor unit 2 in the vehicle width direction is located further to the outer side (one side in the axial direction) than the inner end portion (the other side in the axial direction) of the rim portion 3a in the vehicle width direction. Therefore, at least a part of the motor unit 2 is disposed radially inward of the rim portion 3 a. I.e. at least a part of the motor unit 2 is located inside the wheel 3.

According to the present embodiment, by housing at least a part of the motor unit 2, the hub carrier 50, and the hub bearing 60 in the wheel 3, it is possible to suppress these components from protruding largely inward in the vehicle width direction, and thus to improve the degree of freedom in designing the vehicle.

The end portion of the motor unit 2 on the inner side in the vehicle width direction (the other side in the axial direction) is located on the inner side in the vehicle width direction (the other side in the axial direction) than the end portion of the rim portion 3a on the inner side in the vehicle width direction (the other side in the axial direction). Therefore, at least a part of the motor unit 2 is disposed outside the rim portion 3 a. That is, at least a part of the motor unit 2 is exposed from the wheel 3. When driving the in-wheel motor 1, the vehicle having the in-wheel motor runs. According to the present embodiment, since the motor unit 2 is exposed from the wheel 3, air flow (wind) is generated on the outside of the housing 40 relative to the housing 40 when the vehicle is running, and the housing 40 is cooled. Accordingly, the stator core 19 held by the housing 40 and the oil O in the housing 40 are cooled.

The disk portion 3b is located at an opening on the vehicle width direction outer side (axial direction side) of the rim portion 3 a. The disk portion 3b extends radially inward from an end portion of the rim portion 3a on the vehicle width direction outer side (axial direction one side). A fixing portion 3c is provided at an end portion of the disk portion 3b on the radially inner side. That is, the disk portion 3b connects the rim portion 3a and the fixing portion 3c.

The fixing portion 3c is located at the top center of the wheel 3. The fixing portion 3c has a circular annular plate shape centered on the central axis J. The fixing portion 3c is located on the axially opposite side of the motor unit 2 with respect to the hub carrier 50 and the disc rotor 72. The fixing portion 3c is provided with a plurality of through holes 3d extending in the axial direction. The plurality of through holes 3d are arranged in the circumferential direction.

A fixing screw 69 is inserted through the through hole 3d of the fixing portion 3c, and the fixing screw 69 fixes the fixing portion 3c, the disc rotor 72, and the inner ring 62 of the hub bearing 60 to each other. That is, the wheel 3 is fixed to the inner ring 62 of the hub bearing 60 and the disc rotor 72 at the fixing portion 3 c. The inner ring of the hub bearing 60 is fixed to the output shaft 29 in the circumferential direction. Therefore, the fixing portion 3c is fixed to the output shaft 29. In addition, the wheel 3 is fixed to the output shaft 29.

Configuration of parts

Next, the arrangement of the respective components characteristic of the in-wheel motor 1 of the present embodiment will be described. As shown in fig. 2, the motor unit 2 is located on the vehicle width direction inner side (the other axial side) with respect to the hub frame 50. That is, the motor unit 2 is axially opposed to the hub carrier 50. In addition, the motor unit 2 is fixed to the hub frame 50 at the housing 40. In addition, the hub bearing 60 that rotatably holds the output shaft 29 of the motor unit 2 is held by the hub frame 50 inside the center hole 50a of the hub frame 50. According to the present embodiment, the motor unit 2 is easily detached from the in-wheel motor 1 by releasing the fixation of the motor unit 2 and the hub carrier 50. Therefore, even in a state where the in-wheel motor 1 is mounted to the vehicle and is in contact with the ground via the tire, the motor unit 2 can be detached from the in-wheel motor 1. According to the present embodiment, maintenance of the motor unit 2 is easy.

According to the present embodiment, as shown in fig. 1, the housing 40 is provided with a through hole 41c, and the hub carrier 50 is provided with a screw hole 53a. The housing 40 is fixed to the hub frame 50 by fastening the fixing screw 59 inserted through the through hole 41c to the screw hole 53a. Therefore, the head of the set screw 59 is turned by a wrench or the like with respect to the hub frame 50 on the side where the motor unit 2 is disposed. That is, the head of the set screw 59 is located in the same direction as the motor unit 2 with respect to the hub frame 50. In the mounting operation and the dismounting operation of the motor unit 2, the worker does not need to move to the opposite side of the hub frame 50 after removing the fixing screw 59. According to the present embodiment, the mounting work and the dismounting work of the motor unit 2 can be simplified.

According to the present embodiment, the output shaft 29 is spline-coupled with the inner race 62 of the hub bearing 60. Therefore, by moving the output shaft 29 in the axial direction with respect to the hub bearing 60, the output shaft 29 can be easily disengaged from the hub bearing 60. After the fixing screw 59 is removed, the motor unit 2 is moved to the inside in the vehicle width direction as a whole, whereby the motor unit 2 can be easily disengaged from the in-wheel motor. Therefore, maintenance of the motor unit 2 is easy.

According to the present embodiment, as shown in fig. 3, a seal member 6 is provided between the inner peripheral surface of the insertion hole 48 of the housing 40 and the outer peripheral surface of the output shaft 29, and the seal member 6 seals the inside of the housing 49. Sealing of the housing 49 is completed only by the motor unit 2. Therefore, even if the motor unit 2 is easily detached from the in-wheel motor 1, the seal of the housing portion 49 can be maintained, and the outflow of the oil O from the housing portion 49 can be suppressed.

According to the present embodiment, as shown in fig. 1 and 2, the motor unit 2 is located on the axially opposite side of the fixing portion 3c with respect to the hub frame 50. That is, the motor unit 2 is located on the vehicle width direction inner side (axial direction other side) with respect to the hub shell 50, and the fixing portion 3c is located on the vehicle width direction outer side (axial direction one side). Therefore, in the present embodiment, when the motor unit 2 is detached, the wheel 3 does not need to be detached, and therefore, the motor unit 2 is easily detached.

According to the present embodiment, the motor unit 2 is located on the axially opposite side of the disc rotor 72 with respect to the hub carrier 50. That is, the motor unit 2 is located on the vehicle width direction inner side (axial direction other side) with respect to the hub frame 50, and the disc rotor 72 is located on the vehicle width direction outer side (axial direction one side). Therefore, in the present embodiment, when the motor unit 2 is removed, the disc rotor 72 does not need to be removed, and thus the motor unit 2 is easily removed. Likewise, when the disc rotor 72 is removed, the motor unit 2 does not need to be removed, and thus the disc rotor is easily removed. Therefore, maintenance of the disc rotor 72 is easy.

Modification 1 >

Fig. 6 is a cross-sectional view of a motor unit 102 of modification 1 that can be used in the in-wheel motor 1 of the above-described embodiment.

The same reference numerals are given to the components in the same manner as in the above embodiments, and the description thereof will be omitted.

The motor unit 102 of the present modification includes a motor portion 110, a speed reducer portion 120, a bearing member (1 st bearing member) 4, a bearing member (2 nd bearing member) 107, a resolver 5, a pump portion 30, and oil O (omitted in fig. 6), and a housing 40.

As in the above embodiment, the housing 40 includes the motor portion 110, the speed reducer portion 120, and the housing portion 49 housing the pump portion 30. The housing portion 49 is provided with an oil passage 180 through which the oil supply O circulates in the housing portion 49. The pump unit 30 is provided in the path of the oil passage 180.

Although not shown in fig. 6, the oil passage 180 includes a 1 st oil passage 81 connecting the lower region of the housing portion 49 and the suction port 35 of the pump portion 30, as in the above-described embodiment.

The motor section 110 includes a rotor 111 and an annular stator 17. The rotor 111 rotates around the central axis J. The rotor 111 includes an input shaft 112, a rotor holder 113, a rotor magnet 13a, and a rotor core 13b.

The input shaft 112 extends along a central axis J. The input shaft 112 is provided with a sun gear 21 of a speed reducer section 120 on the outer peripheral surface midway in the axial direction. The input shaft 112 has a 1 st end 112a and a 2 nd end 112b located on both sides of the sun gear 21 in the axial direction.

The 1 st end 112a of the input shaft 112 is located outside (axially on one side) the sun gear 21 in the vehicle width direction. The 1 st end 112a is accommodated in a recess (depression) 29a provided in the output shaft 129.

The 2 nd end 112b of the input shaft 112 is located on the inner side (the other axial side) of the sun gear 21 in the vehicle width direction. The 2 nd end 112b is rotatably supported by the bearing member 4, and the bearing member 4 is held by the housing 40. The 2 nd end 112b is supported by the housing 40 via the bearing member 4.

The input shaft 112 is a hollow shaft centered on the central axis J. In other words, the input shaft 112 is provided with a hollow portion 112c extending in the axial direction and opening at both ends. As described in the subsequent stage, the hollow portion 112c functions as a 2 nd oil passage (an in-input-shaft oil passage) 182, which is a part of the oil passage 180. That is, the 2 nd oil passage 182 extends in the axial direction inside the input shaft 112.

The input shaft 112 has a shaft flange portion 112d extending radially outward. Further, a 3 rd oil passage (an input shaft inner diameter oil passage) 183 extending radially outward from the hollow portion 112c (i.e., the 2 nd oil passage 182) is provided in the input shaft 112.

The 3 rd oil passage 183 communicates the 2 nd oil passage 182 with the outside of the input shaft 112. A part of the oil O flowing through the 2 nd oil passage 182 flows into the 3 rd oil passage 183 by centrifugal force accompanying rotation of the rotor 111. The oil O flowing into the 3 rd oil passage 183 spreads radially outward from the radially outer opening of the 3 rd oil passage 183.

A plurality (8 in the present modification) of 3 rd oil passages 183 are provided in the input shaft 112. The 83 rd oil passages 183 are classified into 4 1

st flow passages

183A and 4 2 nd flow passages 183B. The axial positions of the 4 1 st flow paths 183A are uniform. The 4 1 st flow paths 183A are arranged at equal intervals in the circumferential direction. Similarly, the axial positions of the 4 2 nd flow paths 183B are uniform. The 4 2 nd flow paths 183B are arranged at equal intervals in the circumferential direction.

The 1 st flow path 183A is located further inward (axially on the other side) than the shaft flange portion 112d in the vehicle width direction. On the other hand, the 2 nd flow passage 183B is located further outward (axially one side) than the shaft flange portion 112d in the vehicle width direction. That is, the 1 st flow path 183A is located on the vehicle width direction inner side (the other side in the axial direction) with respect to the 2 nd flow path 183B.

The radially outer opening of the 1 st flow path 183A faces a resolver support portion 114c described later in the radial direction. The radially outer opening of the 2 nd flow path 183B faces a guide portion 114e described later in the radial direction. The axial position of the radially outer opening of the 2 nd flow path 183B overlaps with the axial position of the cylindrical portion 115 of the rotor holder 113 described later.

The rotor holder 113 holds the input shaft 112, the rotor core 13b, and the rotor magnet 13 a. The rotor holder 113 has a bottomed cylindrical shape and is open on the outer side (one axial side) in the vehicle width direction. The axial position of the opening of the rotor holder 113 overlaps with the axial position of the 2 nd coil end 18 b. That is, the axial position of the opening of the rotor holder 113 overlaps the axial position of one coil end 18b of the pair of coil ends 18a, 18 b.

The rotor holder 113 includes: a disk portion 114 that expands in the radial direction; and a cylindrical portion 115 located at the radially outer end of the disk portion 114. A rotor core 13b and a rotor magnet 13a are fixed to the outer peripheral surface of the cylindrical portion 115, and the rotor magnet 13a is fixed via the rotor core 13 b.

A stopper portion 115d protruding radially inward is provided on the inner peripheral surface of the cylindrical portion 115. The blocking portion 115d extends in the circumferential direction. The blocking portion 115d is located in the vicinity of an opening on the vehicle width direction outer side (axial direction side) of the tubular portion 115.

The circular plate portion 114 is located at an opening on the inner side (the other side in the axial direction) of the tubular portion 115 in the vehicle width direction. The disk portion 114 is located between the 1 st flow path 183A and the 2 nd flow path 183B in the axial direction. The disk portion 114 has a 1 st surface 114a facing the inside in the vehicle width direction and a 2 nd surface (bottom surface) 114b facing the outside in the vehicle width direction. The 2 nd surface 114b is axially opposed to the planetary gear 22. A fixing hole 114h is provided in the center of the circular plate 114 in plan view. The fixing hole 114h is fitted to the outer peripheral surface of the input shaft 112.

The 1 st surface 114a of the disk portion 114 is provided with a resolver support portion 114c protruding in the axial direction. The resolver support portion 114c extends in the circumferential direction. That is, the resolver support portion 114c has a cylindrical shape centered on the central axis J. A resolver rotor 5b is fixed to the tip of the resolver support portion 114c.

A disk portion through hole 114f penetrating in the axial direction is provided at an end portion of the disk portion 114 on the outer side in the radial direction. The radially inner end of the blocking portion 115d overlaps the disk portion through hole 114f when viewed from the axial direction.

The resolver support portion 114c is provided with a through hole 114d extending in the radial direction. The through hole 114d extends so as to incline inward in the vehicle width direction (axially on the other side) as going outward in the radial direction. The radially inner opening of the through hole 114d is smoothly continuous from the 1 st surface 114a of the disk portion 114. The radially outer opening of the through hole 114d is radially opposed to the 2 nd coil end 18 b.

The 2 nd surface 114b of the disk portion 114 is provided with a guide portion 114e protruding in the axial direction. That is, the disk portion 114 has a guide portion 114e. The guide portion 114e protrudes from the 2 nd surface 114b toward the planetary gear 22. The guide portion 114e extends annularly in the circumferential direction.

The guide portion 114e is radially opposed to the 2 nd flow path 183B of the 3 rd oil path 183. The radially inward surface of the guide portion 114e is inclined while being curved radially outward as it goes toward the distal end side of the guide portion 114e. Therefore, the oil O transferred along the radially inward surface of the guide portion 114e reaches the tip end of the guide portion 114e, and is scattered toward the planetary gear 22. The guide portion 114e guides the oil O flowing out of the 2 nd flow path 183B of the 3 rd oil path 183 to the planetary gear 22 side.

The speed reducer section 120 is connected to the rotor 111 of the motor section 110, and reduces the rotation of the rotor 111. The speed reducer section 120 includes a sun gear 21, a plurality of planetary gears 22, a plurality of carrier pins 124, a ring gear 23, and an output shaft 129.

The sun gear 21 is provided on the outer peripheral surface of the input shaft 112 of the rotor 111. That is, the sun gear 21 is fixed to the rotor 111. The sun gear 21 rotates together with the input shaft 112.

The plurality of planetary gears 22 are arranged radially outward of the sun gear 21. The planetary gear 22 rotates in mesh with the sun gear 21. The planetary gear 22 rotates about the rotation axis Jp. In addition, the planetary gear 22 revolves around the sun gear 21. A gear center hole 22a extending in the axial direction is provided in the center of the planetary gear 22.

Carrier pins 124 rotatably support the planetary gears 22. The carrier pin 124 revolves around the sun gear 21 together with the planetary gears 22. A bearing member (3 rd bearing member) 22b is disposed between the outer peripheral surface of the carrier pin 124 and the inner peripheral surface of the gear center hole 22a of the planetary gear 22.

The wheel carrier pin 124 is provided with a 1 st pin oil passage 185 and a plurality of 2 nd pin oil passages 186.

The 1 st pin inner oil passage 185 extends in the axial direction inside the wheel carrier pin 124. The 1 st pin inner oil passage 185 opens at an end surface of the wheel carrier pin 124 on the inner side (the other side in the axial direction) in the vehicle width direction. The 1 st pin oil passage 185 opens to the guide portion 114e of the rotor holder 113. The radial position of the tip end of guide portion 114e overlaps the radial position of 1 st pin inner oil passage 185. Therefore, the oil O transferred along the guide portion 114e is introduced into the 1 st pin oil passage 185.

The 2 nd pin oil passage 186 extends radially outward of the rotation axis Jp from the 1 st pin oil passage 185. The 2 nd pin inner oil passage 186 communicates the 1 st pin inner oil passage 185 with the outside of the truck pin 124. The 2 nd pin inner oil passage 186 axially overlaps the planetary gear 22. Therefore, the 2 nd pin oil passage 186 opens inside the gear center hole 22 a. In the present modification, 4 2 nd in-pin oil passages 186 are provided in the carrier pin 124. The 4 2 nd pin oil passages 186 are arranged at equal intervals in the circumferential direction of the rotation axis Jp.

The output shaft 129 supports the wheel carrier pin 124. The output shaft 129 rotates around the center axis J with revolution of the planetary gear 22 and the carrier pin 124. The output shaft 129 is rotatably supported by the hub bearing 60.

The output shaft 129 has: an output shaft main body portion 129A having a columnar shape extending in the axial direction about the central axis J; and a wheel frame (flange portion) 125.

The wheel carrier 125 has a disk shape centered on the central axis J.

The wheel carrier 125 is provided with a plurality (3 in this modification) of 1 st pin holding holes (pin holding holes) 125a penetrating in the axial direction. The wheel carrier 125 holds a plurality of wheel carrier pins 124 in the 1 st pin holding holes 125a. A wheel frame cover 126 is fixed to the wheel frame 125.

In the axial direction, the 1 st thrust washer 22c is interposed between the carrier 125 and the pinion 22 and between the carrier cover 126 and the pinion 22, respectively.

A recess 129a is provided in an end surface of the wheel frame 125 facing the vehicle width direction inner side (the other side in the axial direction). That is, the wheel carrier 125 is provided with a recess 129a that opens in the axial direction.

The recess 129a extends along the central axis J. The recess 129a is circular with the central axis J as a center in a plan view. The 1 st end 112a of the input shaft 112 is accommodated in the recess 129a.

The 2 nd thrust washer 29c is interposed between the bottom surface of the recess 129a and the 1 st end 112a of the input shaft 112. A bearing member (2 nd bearing member) 107 is provided between the inner peripheral surface of the recess 129a and the outer peripheral surface of the 1 st end 112a. That is, the 1 st end 112a of the input shaft 112 is supported by the carrier 125 via the bearing member 107. The 2 nd end 112b of the input shaft 112 is supported by the housing 40 via the bearing member 4. Therefore, according to the present modification, the input shaft 112 is rotatably supported so as to be held at both ends. This suppresses eccentric rotation of the input shaft 112, and improves the transmission efficiency of the gears in the speed reducer section 120.

The ring gear 23 is fixed to the 2 nd base plate 43 of the housing 40. Therefore, when the sun gear 21 rotates, the planetary gears 22 rotate while revolving around the sun gear 21. The carrier 125 rotates around the center axis J with the revolution of the planetary gear 22. The wheel carrier 125 is fixed to the wheel 3 via an output shaft main body portion 129A. Thus, the rotation of the wheel carrier 125 is transmitted to the wheel 3.

Further, as shown in the present modification, by fixing the ring gear 23 to the housing 40, the sun gear 21 connected to the input shaft 112 and the planetary gear 22 connected to the carrier 125 are rotated in the same direction. Therefore, wear of the bearing member 107 located between the inner peripheral surface of the recess 129a provided in the carrier 125 and the outer peripheral surface of the input shaft 112 can be suppressed.

In the present modification, the sun gear 21, the planetary gears 22, and the ring gear 23 are housed entirely inside the cylindrical portion 115 of the rotor holder 113 in the radial direction. More specifically, the inner (axially other) end surfaces of the sun gear 21, the planetary gears 22, and the ring gear 23 in the vehicle width direction are positioned further outward (axially one) than the inner (axially other) end surfaces of the tubular portion 115 in the vehicle width direction. The outer (one side in the axial direction) end surfaces of the sun gear 21, the planetary gears 22, and the ring gear 23 in the vehicle width direction are positioned further inward (the other side in the axial direction) than the outer (one side in the axial direction) end portions of the tubular portion 115 in the vehicle width direction. Therefore, the axial dimension of the motor unit 102 can be made smaller.

Next, the oil passage 180 through which the oil supply O circulates in the housing portion 49 of the housing 40 will be described. The oil passage 180 includes a 1 st oil passage 81, a 2 nd oil passage 182, a 3 rd oil passage 183, a 1 st in-pin oil passage 185, and a 2 nd in-pin oil passage 186.

When driving the in-wheel motor 1, the pump section 30 is also driven as the input shaft 112 rotates. When the pump unit 30 is driven, the oil O stored in the lower region of the storage unit 49 moves from the suction port 35 into the pump chamber 31 through the 1 st oil passage 81. The oil O in the pump chamber 31 moves from the pump outlet 36 to the 2 nd oil passage 182.

A part of the oil O in the 2 nd oil passage 182 flows into the 3 rd oil passage 183 by centrifugal force based on the rotation of the input shaft 112. Further, a part of the oil O in the 2 nd oil passage 182 reaches an end portion of the 2 nd oil passage 182 on the outer side (one side in the axial direction) in the vehicle width direction.

The oil O flowing into the 3 rd oil passage 183 moves radially outward in the 3 rd oil passage 183 by centrifugal force. The oil O reaching the radially outer side of the 3 rd oil passage 183 is scattered radially outward from the outer peripheral surface of the input shaft 112.

The axial position of the 1 st flow path 183A of the 3 rd oil passage 183 overlaps the axial position of the resolver support portion 114c. The oil O scattered radially outward from the 1 st flow path 183A reaches the resolver support portion 114c. Then, the 1 st coil end 18a is reached through the through hole 114d of the resolver support portion 114c, and the 1 st coil end 18a is cooled.

In addition, a part of the oil O diffused from the opening of the 1 st flow path 183A is supplied to the bearing member 4. The oil O supplied to the bearing member 4 promotes lubrication of the bearing member 4, and suppresses wear of the bearing member 4.

The axial position of the 2 nd flow path 183B of the 3 rd oil passage 183 overlaps the axial position of the guide portion 114e. The oil O scattered radially outward from the 2 nd flow path 183B reaches the guide portion 114e. The oil O having reached the guide portion 114e is transferred along the radially inward surface of the guide portion 114e, and is scattered toward the planetary gear 22.

A part of the oil O scattered toward the planetary gear 22 is supplied to the tooth surface of the planetary gear 22 by the guide 114e. This can improve the transmission efficiency of the sun gear 21, the planetary gears 22, and the ring gear 23. Further, wear of the sun gear 21, the planetary gears 22, and the ring gear 23 can be suppressed.

A part of the oil O scattered toward the planetary gear 22 is guided by the guide portion 114e into the 1 st pin oil passage 185 provided in the carrier pin 124. A part of the oil O flowing into the 1 st pin oil passage 185 is guided to the outer peripheral surface of the wheel carrier pin 124 via the 2 nd pin oil passage 186. A bearing member 22b is disposed between the outer peripheral surface of the carrier pin 124 and the inner peripheral surface of the gear center hole 22 a. According to the present modification, the oil O is supplied to the bearing member 22b, and the lubricity of the bearing member 22b can be improved. The oil O guided to the outer peripheral surface of the carrier pin 124 flows along the end surface of the planetary gear 22 and is supplied to the 1 st thrust washer 22c. According to this modification, the lubricity of the 1 st thrust washer 22c can be improved. The oil O flows radially outward and is supplied to tooth surfaces of the planetary gear 22 and the ring gear 23.

In the present modification, the guide portion 114e extends annularly in the circumferential direction. Therefore, the oil O scattered from the 2 nd flow path 183B of the 3 rd oil path 183 can be captured as much as possible and guided to the 1 st pin inner oil path 185.

The guide portion 114e does not have to extend annularly in the circumferential direction. As an example, the disk portion 114 may have a plurality of guide portions arranged in a circumferentially discrete manner.

Further, a part of the oil O scattered from the guide portion 114e reaches the inner peripheral surface of the cylindrical portion 115 of the rotor holder 113.

The 2 nd oil passage 182 opens at the 1 st end 112a of the input shaft 112. Accordingly, the oil O of the 2 nd oil passage 182 flows out from the 2 nd oil passage 182 at the 1 st end 112a of the input shaft 112. The 1 st end 112a of the input shaft 112 is accommodated in a recess 129a provided in the output shaft 129. Therefore, the 2 nd oil passage 182 opens in the recess 129a. The oil O flows from the 2 nd oil passage 182 into the recess 129a.

The oil O flowing into the recess 129a is supplied to the 2 nd thrust washer 29c and the bearing member 107 accommodated in the recess 129a. This allows smooth rotation of the input shaft 112.

In addition, a part of the oil O flowing into the concave portion 129a moves in the axial direction, and flows out from the opening of the concave portion 129a. A part of the oil O flowing out from the opening of the recess 129a flows radially outward and flows into the gap between the carrier 125 and the planetary gear 22. The oil O flowing into the gap between the carrier 125 and the pinion 22 improves the lubricity of the 2 nd thrust washer 29c interposed between the carrier 125 and the pinion 22.

The cylindrical portion 115 of the rotor holder 113 is located radially outward of the planetary gear 22. Therefore, a part of the oil O scattered radially outward of the planetary gear 22 is caught by the inner peripheral surface of the cylindrical portion 115 via the 1 st pin inner oil passage 185.

A blocking portion 115d is provided on the inner peripheral surface of the cylindrical portion 115. The blocking portion 115d blocks the oil O that is desired to flow out from the opening on the outer side (one side in the axial direction) of the tubular portion 115 in the vehicle width direction at the inner peripheral surface of the tubular portion 115. The disk portion 114 is provided with a disk portion through hole 114f extending in the axial direction. The oil O trapped by the blocking portion 115d and accumulated on the inner peripheral surface of the cylindrical portion 115 passes through the disc portion through hole 114f. The oil O passing through the disc portion through hole 114f is scattered radially outward to reach the 1 st coil end 18a, and cools the 1 st coil end 18 a. The oil O that has passed over the blocking portion 115d is scattered radially outward from the opening of the rotor holder 113. The oil O scattered from the opening of the rotor holder 113 cools the 2 nd coil end 18 b. According to this modification. By providing the blocking portion 115d and the disk portion through hole 114f in the rotor holder 113, the amount of the oil O scattered from the rotor holder 113 toward the 1 st coil end 18a can be made close to the amount of the oil O scattered toward the 2 nd coil end 18 b. This makes it possible to cool the 1 st coil end 18a and the 2 nd coil end 18b in a balanced manner.

Modification 2 >

Fig. 7 is a partial cross-sectional view of in-wheel motor 201 according to modification 2 of the above embodiment. The in-wheel motor 201 of modification 2 is different from the above embodiment mainly in the sealing structure of the motor unit 202.

The same reference numerals are given to the same constituent elements as those of the above embodiment, and the description thereof will be omitted.

The in-wheel motor 201 of modification 2 includes a housing 240, a hub bearing 260, a speed reducer portion 20, and a wheel 3. The decelerator part 20 has an output shaft 29.

Although not shown in fig. 7, in-wheel motor 201 includes motor unit 10, pump unit 30, and oil O accommodated in accommodating portion 249 of case 240. An oil passage 80 for supplying oil O circulation is provided in the housing 240.

The in-wheel motor 201 of the present modification does not have the hub carrier 50 of the above embodiment. Accordingly, in-wheel motor 201 is directly fixed to the vehicle at housing 240.

The housing 240 is provided with a through-insertion hole 248 penetrating in the axial direction. That is, the housing 240 is provided with a through-insertion hole 248 connecting the inside and outside of the storage portion 249. The output shaft 29 is inserted through the insertion hole 248. A hub bearing 260 is disposed between the inner peripheral surface of the insertion hole 248 and the outer peripheral surface 29d of the output shaft 29.

The hub bearing 260 is located inside the through-insertion hole 248 of the housing 240. The hub bearing 260 rotatably supports the output shaft 29 with respect to the housing 240. The hub bearing 260 has an outer race 261, an inner race 262, a plurality of rolling bodies 263 located between the outer race 261 and the inner race 262, and a seal member 206 located between the outer race 261 and the inner race 262.

Hub bearing 260 is fixed to housing 240 at outer race 261. That is, the hub bearing 260 is held by the housing 240 inside the through-insertion hole 248. In addition, a hub bearing 260 is fixed to the output shaft 29 at an inner race 262.

The seal member 206 is provided at a portion where the outer race 261 and the inner race 262 are axially opposed. The seal member 206 is fixed to one of the outer ring 261 and the inner ring 262 and contacts the other. The seal member 206 suppresses the outflow of the oil O in the storage portion 249 from the gap between the outer ring 261 and the inner ring 262. The seal member 206 prevents foreign matter from entering the housing portion 249 from the gap between the outer ring 261 and the inner ring 262.

A 1 st O-ring (sealing member) 207A is provided between the outer race 261 of the hub bearing 260 and the housing 240. The 1 st O-ring 207A suppresses the outflow of the oil O from the gap between the hub bearing 260 and the housing 240. The 1 st O-ring 207A suppresses intrusion of foreign matter into the storage portion 249 from the gap between the hub bearing 260 and the housing 240.

A 2 nd O-ring (sealing member) 207B is provided between the inner ring 262 of the hub bearing 260 and the output shaft 29. The 2 nd O-ring 207B suppresses outflow of oil O from the gap between the inner ring 262 and the output shaft 29. The 1 st O-ring 207A suppresses intrusion of foreign matter into the storage portion 249 from the gap between the inner ring 262 and the output shaft 29.

Modification 3 >

Fig. 8 is a partial cross-sectional view of a motor unit 302 of modification 1 that can be employed in the in-wheel motor 1 of the above embodiment. The motor unit 302 of the present modification is different from the above embodiment mainly in the structure of the oil passage provided in the rotor 311.

The same reference numerals are given to the same constituent elements as those of the above embodiment and the constituent elements of each modification, and the description thereof will be omitted.

As in the above-described embodiment, the motor unit 302 of the present modification includes the motor portion 310, the speed reducer portion 20 (omitted in fig. 8), the bearing member 4, the bearing member 107, the resolver 5, the pump portion 30 (omitted in fig. 8), the oil O (omitted in fig. 8), and the housing 40 (omitted in fig. 8).

As in the above embodiment, the housing 40 (omitted in fig. 8) has a housing portion 49. The housing portion 49 is provided with an oil passage 380 through which the oil supply O circulates in the housing portion 49. The pump unit 30 (omitted in fig. 8) is provided in the path of the oil passage 380. The oil passage 380 includes a 1 st oil passage 81 (omitted in fig. 8) connecting the lower region of the housing portion 49 and the pump portion 30, similarly to the above embodiment.

The motor unit 310 of the present modification example includes a rotor 311 and an annular stator 17. The rotor 311 rotates around the central axis J. The rotor 311 has an input shaft 312, a rotor holder 313, rotor magnets 13a, a rotor core 13b, and an end cap (annular member) 316.

The input shaft 312 is a hollow shaft centered on the central axis J. In other words, the input shaft 312 is provided with a hollow portion 312c extending in the axial direction and opening at both ends. As described in the subsequent stage, the hollow portion 312c functions as a 2 nd oil passage (in-input-shaft oil passage) 382, which is a part of the oil passage 380. That is, the 2 nd oil passage 382 extends in the axial direction inside the input shaft 312.

The input shaft 312 is provided with a 3 rd oil passage (input shaft inner oil passage) 383 extending radially outward from the 2 nd oil passage 382. The 3 rd oil passage 383 communicates the 2 nd oil passage 382 with the outside of the input shaft 312. A part of the oil O flowing through the 2 nd oil passage 382 flows into the 3 rd oil passage 383 by centrifugal force accompanying rotation of the rotor 311. The oil O flowing into the 3 rd oil path 383 spreads radially outward from the radially outward opening of the 3 rd oil path 383. The axial position of the radially outer opening of the 3 rd oil passage 383 overlaps with the axial position of the cylindrical portion 315. That is, the radially outer opening of the 3 rd oil path 383 is radially opposed to the cylindrical portion 315 of the rotor holder 313.

The rotor holder 313 holds the input shaft 312, the rotor core 13b, and the rotor magnet 13a. The rotor holder 313 has a bottomed cylindrical shape and is open on the outer side (one axial side) in the vehicle width direction. The axial position of the opening of the rotor holder 313 overlaps with the axial position of the 2 nd coil end 18 b. That is, the axial position of the opening of the rotor holder 313 overlaps with the axial position of one coil end 18b of the pair of coil ends 18a, 18 b.

The rotor holder 313 has: a disk portion 314 that expands in the radial direction; a cylindrical portion 315 located at the radially outer end of the disk portion 314; and a flange portion 315f located on the outer side (axial direction side) of the tubular portion 315 in the vehicle width direction. A rotor core 13b and a rotor magnet 13a are fixed to the outer peripheral surface of the cylindrical portion 315, and the rotor magnet 13a is fixed via the rotor core 13 b.

The flange portion 315f extends radially outward from an end portion of the tubular portion 315 on the vehicle width direction outer side (axial direction side). The flange portion 315f has a plate shape extending along a plane perpendicular to the axial direction. The flange portion 315f has a circular outer diameter when viewed from the axial direction. The flange portion 315f and the end cap 316 axially sandwich the rotor core 13b and the rotor magnet 13a.

The circular plate portion 314 is located at an opening on the inner side (the other side in the axial direction) of the tubular portion 315 in the vehicle width direction. The disk portion 314 has a 1 st surface (opposite surface) 314a facing the inside in the vehicle width direction and a 2 nd surface (bottom surface) 314b facing the outside in the vehicle width direction. The 2 nd surface 314b is a surface facing the axial direction and surrounded by the cylindrical portion 315. The 1 st surface 314a is a surface located opposite to the 2 nd surface 314b.

The disc portion 314 is provided with an oil introduction hole 314f penetrating in the axial direction. The oil introduction hole 314f connects the 1 st surface 314a and the 2 nd surface 314 b. The oil introduction hole 314f has: an inflow opening 314fb located on the vehicle width direction outer side (axial direction side); and an outflow opening 314fa located on the vehicle width direction inner side (the other axial side). The inflow opening 314fb opens at the 2 nd face 314 b. The outflow opening 314fa opens on the 1 st surface 314 a.

The oil introduction hole 314f extends linearly. The oil introduction hole 314f is inclined radially outward as it is directed inward in the vehicle width direction (axially on the other side). That is, the oil introduction hole 314f is inclined radially outward from the inflow opening 314fb toward the outflow opening 314 fa.

The inflow opening 314fb opens across the 2 nd surface 314b of the disk portion 314 and the inner peripheral surface of the cylindrical portion 315. Therefore, on the inner peripheral surface of the cylindrical portion 315, a part of the inner peripheral surface of the oil introduction hole 314f extends in a groove shape. The inner peripheral surface of the oil introduction hole 314f and the inner peripheral surface of the cylindrical portion 315 are adjacent to each other. That is, the oil introduction hole 314f extends continuously from the inner peripheral surface of the cylindrical portion 315.

End cap 316 extends circumferentially in an annular shape. End cap 316 has a plate shape extending along a plane perpendicular to the axial direction. End cap 316 is secured to rotor cage 313. More specifically, the end cap 316 is screwed to the circular plate portion 314 from the vehicle width direction inner side (the other axial side).

At least a portion of the 1 st surface 314a of the disk portion 314 is covered by the end cap 316. End cap 316 has an opposing face 316c that opposes 1 st face 314 a. At least a portion of the opposing face 316c is in contact with the 1 st face 314 a.

The opposing surface 316c is provided with a groove portion 316a recessed in the axial direction and extending in the radial direction. That is, the end cap 316 is provided with a groove portion 316a. The groove portion 316a faces the outflow opening 314 fa. The groove portion 316a opens radially outward at the radially outer edge of the end cap 316. The axial position of the radially outer opening of the groove portion 316a overlaps with the axial position of the 1 st coil end 18 a. That is, the radially outer opening of the groove 316a is radially opposed to the 1 st coil end 18 a.

Next, the oil passage 380 will be described. The oil passage 380 includes a 1 st oil passage 81 (omitted in fig. 8), a 2 nd oil passage 382, and a 3 rd oil passage 383.

When the pump unit 30 (omitted in fig. 8) is driven with the rotation of the input shaft 312, the oil O is supplied to the 2 nd oil passage 382. A part of the oil O in the 2 nd oil passage 382 flows into the 3 rd oil passage 383 by centrifugal force based on the rotation of the input shaft 312.

The oil O flowing into the 3 rd oil path 383 moves radially outward in the 3 rd oil path 383 by centrifugal force. The oil O reaching the radially outer side of the 3 rd oil path 383 is scattered radially outward from the outer peripheral surface of the input shaft 312. The oil O scattered from the 3 rd oil path 383 reaches the inner peripheral surface of the cylindrical portion 315 of the rotor holder 313.

A part of the oil O reaching the inner peripheral surface of the cylindrical portion 315 is scattered radially outward from the opening of the rotor holder 313. The oil O scattered from the opening of the rotor holder 313 cools the 2 nd coil end 18 b.

In addition, a part of the oil O reaching the inner peripheral surface of the cylindrical portion 315 is introduced into the oil introduction hole 314f from the inflow opening 314 fb. The oil O introduced into the oil introduction hole 314f flows out from the outflow opening 314fa and also flows into the groove portion 316a of the end cap 316. The oil O in the groove 316a is scattered radially outward from the opening of the groove 316 a. The oil O scattered from the opening of the groove 316a reaches the 1 st coil end 18a, and cools the 1 st coil end 18 a.

According to this modification, the disc portion 314 is provided with an oil introduction hole 314f. Therefore, the oil O can be scattered to the inner side (the other side in the axial direction) of the rotor holder 313 in the vehicle width direction via the oil introduction hole 314f. Further, according to the present modification, the oil O is scattered from the opening of the rotor holder 313 to the vehicle width direction outside (axial direction side) of the rotor holder 313. Therefore, according to this modification, the oil can be scattered toward both sides in the axial direction with respect to the rotor holder 313, and the pair of coil ends 18a and 18b can be cooled uniformly.

According to the present modification, the oil introduction hole 314f extends continuously from the inner peripheral surface of the cylindrical portion 315. Therefore, the oil O on the inner peripheral surface of the cylindrical portion 315 can be smoothly introduced into the oil introduction hole 314f.

According to the present modification, the oil introduction hole 314f opens across the 2 nd surface 314b and the inner peripheral surface of the cylindrical portion 315 at the inflow opening 314 fb. That is, the inflow opening 314fb is not located radially inward of the inner peripheral surface of the cylindrical portion 315. Therefore, the oil O reaching the inner peripheral surface of the cylindrical portion 315 can smoothly flow into the oil introduction hole 314f from the inflow opening 314 fb.

According to the present modification, the oil introduction hole 314f is inclined radially outward from the inflow opening 314fb toward the outflow opening 314 fa. Therefore, the oil O in the oil introduction hole 314f smoothly flows toward the outflow opening 314fa by centrifugal force. According to this modification, the oil O in the oil introduction hole 314f can be smoothly discharged from the discharge opening 314 fa.

According to the present modification, the outflow opening 314fa is opposed to the groove portion 316a of the end cap 316. In addition, the groove portion 316a of the end cap 316 extends in the radial direction and opens at the radially outer edge of the end cap 316. Therefore, the oil O flowing out from the outflow opening 314fa can be scattered in the radial direction in agreement with a desired position in the axial direction.

According to this modification, the radially outer opening of the groove 316a is radially opposed to one of the pair of coil ends 18a, 18b (the 1 st coil end 18 a). Therefore, the oil O scattered from the radially outer opening of the groove 316a collides with the 1 st coil end 18a, and the 1 st coil end 18a can be cooled effectively.

While the embodiments and modifications of the present invention have been described above, the structures and combinations thereof in the embodiments and modifications are examples, and the structures may be added, omitted, substituted, and other modified without departing from the spirit of the present invention. The present invention is not limited to the embodiments.

For example, the case where a gear mechanism is used as the speed reducer portion of the above embodiment and modification is exemplified, but a roller mechanism speed reducer may be used.

In the motor unit described above, the case where the output shaft that outputs the power of the motor unit is connected to the planetary gear is exemplified. However, the output shaft may be connected to the ring gear.

For example, the motor units according to the above embodiments and modifications thereof are not limited to vehicles, and can be widely used in various devices having wheels, such as unmanned conveyors, agricultural implements, and robots such as cleaning robots.

Description of the reference numerals

1. 201: an in-wheel motor; 2. 102, 202: a motor unit; 3: a wheel; 3a: a rim portion; 3c, 26b: a fixing part; 3d, 41c, 72d, 72e, 114d: a through hole; 4: bearing parts (1 st bearing part); 6. 206: a sealing member; 9: a vehicle; 10. 110, 310: a motor section; 11. 111, 311: a rotor; 12. 112, 312: an input shaft; 12a, 112a: a 1 st end; 12b, 112b: a 2 nd end; 13. 113, 313: a rotor holder; 13a: a rotor magnet; 13c: a holding hole; 14. 114: a circular plate portion; 14a, 114a, 314b: plane 1 (opposite); 14b, 114b, 314b: 2 nd (bottom) surface; 15. 115: a cylindrical portion; 17: a stator; 18: a coil; 18a, 18b: a coil end; 19: a stator core; 20. 120: a speed reducer section; 21: a sun gear; 22: a planetary gear; 22a: a gear central bore; 22b: a bearing member; 22c: a 1 st thrust washer; 23: a gear ring; 23d: a ring gear through hole; 24. 124: wheel carrier pins; 25. 125: a wheel carrier; 25a, 125a: 1 st pin holding hole (pin holding hole); 29. 129: an output shaft; 29a, 129a: a concave portion; 29b: a groove portion; 29c: a 2 nd thrust washer; 29d: an outer peripheral surface; 30: a pump section; 31: a pump chamber; 32: an external gear; 33: an internal tooth gear; 35: a suction inlet; 36: a pump outlet; 40. 240: a housing; 43j: a 2 nd mating surface; 48. 248: penetration holes; 49. 249: a storage section; 50: a hub frame; 50a: a central aperture; 53a, 62b, 72f: a threaded hole; 53j: a 1 st fitting surface; 59. 64, 69, 72c: a fixing screw; 60. 260: a hub bearing; 61. 261: an outer ring; 62. 262: an inner ring; 62c: an inner peripheral surface; 63. 263: a rolling element; 70: a brake section; 71: a brake caliper; 71b: a brake pad; 72: a disc-shaped rotor; 80. 180, 380: an oil path; 81: the 1 st oil way; 82. 182: a 2 nd oil passage; 82. 182, 382: the 2 nd oil path (the oil path in the input shaft); 83. 183, 383: a 3 rd oil path; 83. 183: a 3 rd oil passage (an input shaft inner diameter oil passage); 84: an oil way in the wheel frame; 85. 185: the 1 st pin inner oil way; 86. 186: the 2 nd pin inner oil way; 87: a 3 rd pin inner oil path; 107: bearing parts (2 nd bearing part); 114e: a guide section; 114f: a disk portion through hole; 115d: a blocking part; 207A: a 1 st O-ring (sealing member); 207B: a 2 nd O-ring (sealing member); 314f: an oil introduction hole; 316: an end cap (annular member); 316a: a groove portion; 314fa: an outflow opening; 314fb: an inflow opening; j: a central axis; o: and (3) oil.

Claims

1. An in-wheel motor mounted on a vehicle, wherein,

the in-wheel motor has:

a motor unit having a rotor that rotates around a central axis and an annular stator that is positioned radially outward of the rotor;

a speed reducer unit connected to the rotor for reducing the rotation of the rotor;

a housing fixed to the vehicle and having a housing portion that houses the motor portion and the speed reducer portion; and

a wheel connected to the speed reducer section, transmitting rotation of the rotor through the speed reducer section,

the rotor has:

an input shaft extending along the central axis;

a rotor magnet radially opposed to the stator; and

a rotor holder for holding the input shaft and the rotor magnet,

the rotor holder has:

a cylindrical portion having a cylindrical shape centered on the central axis, the rotor magnet being fixed to an outer peripheral surface thereof; and

a circular plate part which is positioned at one opening of the tubular part and is fixedly provided with the input shaft,

the speed reducer section has:

a sun gear provided on an outer peripheral surface of the input shaft;

a plurality of planetary gears disposed radially outward of the sun gear and meshed with the sun gear;

A ring gear disposed radially outward of the plurality of planetary gears and meshed with the plurality of planetary gears;

a plurality of carrier pins inserted into gear center holes provided in the planetary gears, the carrier pins supporting the plurality of planetary gears, respectively; and

a wheel carrier holding a plurality of the wheel carrier pins,

at least a part of the planetary gear is housed inside the cylindrical portion in the radial direction,

the in-wheel motor has:

an oil stored in the storage section; and

a pump section located in the housing section and driven via the rotor,

the pump section has:

an external gear fixed to an end of the input shaft;

an internal gear that surrounds the external gear in a radial direction and meshes with the external gear;

a pump chamber provided in the housing and accommodating the internal gear and the external gear;

a suction port that sucks the oil into the pump chamber; and

a pump outlet that discharges the oil from the pump chamber,

an oil passage through which the oil circulates is provided in the housing portion,

the oil passage includes:

a 1 st oil passage connecting a lower region of the housing portion to the suction port;

A 2 nd oil passage extending axially inside the input shaft and connected to the pump outlet; and

a 3 rd oil passage extending radially outward from the 2 nd oil passage to communicate the 2 nd oil passage with an outside of the input shaft,

the ring gear is provided with a ring gear through hole which is located below the central axis and penetrates in the radial direction.

2. The in-wheel motor according to claim 1, wherein,

the planetary gear is housed entirely inside the cylindrical portion in the radial direction.

3. The in-wheel motor according to claim 1 or 2, wherein,

the input shaft has a 1 st end and a 2 nd end on both sides of the sun gear in an axial direction,

the 2 nd end portion is rotatably supported on the housing via the 1 st bearing member,

the 1 st end is rotatably supported on the wheel carrier via a 2 nd bearing member.

4. The in-wheel motor according to claim 1 or 2, wherein,

the gear ring is fixed on the shell body,

the planetary gears revolve around the sun gear,

the carrier is fixed to the wheel and rotates around the center axis along with revolution of the planetary gear.

5. The in-wheel motor according to claim 1 or 2, wherein,

a recess extending along the central axis and opening in an axial direction is provided on the wheel carrier,

a 2 nd bearing member is provided between the inner peripheral surface of the recess and the outer peripheral surface of the 1 st end portion,

the 2 nd oil passage is open at the 1 st end portion.

6. The in-wheel motor according to claim 5, wherein,

a thrust washer is interposed between the bottom surface of the recess and the 1 st end portion.

7. The in-wheel motor according to claim 1 or 2, wherein,

the axial position of the opening radially outside the 3 rd oil passage overlaps with the axial position of the cylindrical portion,

a blocking part extending along the circumferential direction and protruding towards the radial inner side is arranged on the inner circumferential surface of the cylindrical part,

the disk portion is provided with a disk portion through hole penetrating in the axial direction.

8. The in-wheel motor according to claim 1 or 2, wherein,

the stator has:

an annular stator core having a plurality of teeth; and

a coil wound around the teeth,

the coil has a pair of coil ends protruding axially to both sides with respect to the stator core,

The opening of the 3 rd oil passage on the radially outer side is radially opposed to one of the pair of coil ends.

9. The in-wheel motor according to claim 1 or 2, wherein,

the stator has:

an annular stator core having a plurality of teeth; and

a coil wound around the teeth,

an axial position of an opening of the rotor holder overlaps an axial position of one of the pair of coil ends.

10. The in-wheel motor according to claim 1 or 2, wherein,

the speed reducer part is provided with an output shaft for outputting power,

the shell is provided with a penetrating insertion hole for penetrating and inserting the output shaft,

a sealing member is provided between an inner peripheral surface of the insertion hole and an outer peripheral surface of the output shaft.

11. The in-wheel motor according to claim 1 or 2, wherein,

the in-wheel motor has a hub bearing,

the speed reducer part is provided with an output shaft for outputting power,

the hub bearing is held by the housing inside the penetration hole, supports the output shaft rotatably with respect to the housing,

The hub bearing has:

an inner ring;

an outer ring;

a plurality of rolling elements located between the inner ring and the outer ring; and

and a seal member located between the inner ring and the outer ring.

12. The in-wheel motor according to claim 11, wherein,

sealing members are provided between the hub bearing and the housing and between the hub bearing and the output shaft.

13. The in-wheel motor according to claim 1 or 2, wherein,

the inner peripheral surface of the cylindrical portion is radially opposed to the opening of the 3 rd oil passage on the radially outer side,

the disk portion has:

a bottom surface facing the axial direction and surrounded by the cylindrical portion; and

an opposite side located on an opposite side of the bottom surface,

an oil introduction hole penetrating in the axial direction and connecting the bottom surface and the opposite surface is provided in the disk portion,

the oil introduction hole extends continuously from an inner peripheral surface of the cylindrical portion.

14. The in-wheel motor according to claim 13, wherein,

the oil introduction hole opens across the bottom surface and the inner peripheral surface of the cylindrical portion.

15. The in-wheel motor according to claim 13, wherein,

the oil introduction hole has an inflow opening opened at the bottom surface and an outflow opening opened at the opposite surface,

The oil introduction hole is inclined radially outward as going from the inflow opening to the outflow opening.

16. The in-wheel motor according to claim 13, wherein,

the rotor holder has an annular member extending annularly in a circumferential direction and covering at least a part of the opposite faces,

the oil introduction hole has an outflow opening opened at the opposite side,

the annular member is provided with a groove portion extending in a radial direction and opposed to the outflow opening,

the groove portion opens radially outward at a radially outer edge of the annular member.

17. The in-wheel motor according to claim 16, wherein,

the stator has:

an annular stator core having a plurality of teeth; and

a coil wound around the teeth,

an opening of a radially outer side of the groove portion is radially opposed to one of the pair of coil ends.

18. An in-wheel motor mounted on a vehicle, wherein,

the in-wheel motor has:

the rotor has:

an input shaft extending along the central axis;

a rotor magnet radially opposed to the stator; and

a rotor holder for holding the input shaft and the rotor magnet,

the rotor holder has:

the speed reducer section has:

a sun gear provided on an outer peripheral surface of the input shaft;

A wheel carrier holding a plurality of the wheel carrier pins,

the in-wheel motor has:

an oil stored in the storage section; and

a pump section located in the housing section and driven via the rotor,

the pump section has:

an external gear fixed to an end of the input shaft;

a suction port that sucks the oil into the pump chamber; and

a pump outlet that discharges the oil from the pump chamber,

the oil passage includes:

The disk portion has:

an opposite side located on an opposite side of the bottom surface,

19. The in-wheel motor according to claim 18, wherein,

20. An in-wheel motor according to claim 18 or 19, wherein,

21. An in-wheel motor according to claim 18 or 19, wherein,

the oil introduction hole has an outflow opening opened at the opposite side,

22. The in-wheel motor according to claim 21, wherein,

the stator has:

an annular stator core having a plurality of teeth; and

a coil wound around the teeth,