CN111465522A - In-wheel motor - Google Patents

Abstract

One embodiment of an in-wheel motor includes: a motor unit having an output shaft that rotates around a central axis and outputting power from the output shaft; a hub carrier that extends along a plane perpendicular to the central axis, is fixed to the vehicle, and is provided with a central hole through which the output shaft is inserted; a hub bearing which is held by the hub carrier inside the center hole and supports the output shaft to be rotatable with respect to the hub carrier; and a wheel fixed to the output shaft. The motor unit has: a motor unit having a rotor that rotates around a central axis and an annular stator that is positioned radially outside the rotor; a speed reducer unit that reduces the rotation of the rotor and outputs the rotation from the output shaft; and a housing that houses the motor portion and the reducer portion. The motor unit is axially opposite the hub carrier and is fixed to the hub carrier in the housing.

Description

In-wheel motor

Technical Field

The present invention relates to an in-wheel motor. The present application claims priority based on U.S. provisional patent application No. 62/599870, filed on 12/18/2017, U.S. provisional patent application No. 62/627287, filed on 2/7/2018, and japanese application No. 2018-070049, filed on 3/30/2018, the contents of which are incorporated herein by reference.

Background

Japanese laid-open patent publication No. 2017-159883 discloses an in-wheel motor as follows: a motor unit for directly driving the wheel is provided in the wheel.

Documents of the prior art

Patent document

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

Disclosure of Invention

Problems to be solved by the invention

In the in-wheel motor, regular maintenance of the motor unit is required. Therefore, the in-wheel motor is required to have a structure in which the motor unit can be easily attached to and detached from the in-wheel motor.

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 easily attached and detached.

Means for solving the problems

An in-wheel motor according to an aspect of the present invention is an in-wheel motor mounted on a vehicle, including: a motor unit having an output shaft that rotates around a central axis and outputting power from the output shaft; a hub carrier that extends along a plane perpendicular to the center axis, is fixed to the vehicle, and is provided with a center hole through which the output shaft is inserted; a hub bearing that is held by the hub carrier inside the center hole and that supports the output shaft rotatably with respect to the hub carrier; and a wheel fixed to the output shaft. The motor unit has: a motor unit having a rotor that rotates around a central axis and an annular stator that is positioned radially outside the rotor; a speed reducer unit that reduces the rotation of the rotor and outputs the rotation from the output shaft; and a housing that houses the motor unit and the reducer unit. The motor unit is axially opposed to the hub carrier and is fixed to the hub carrier in the housing.

Effects of the invention

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

Drawings

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

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

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

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

Fig. 5 is a cross-sectional view of an embodiment pump section.

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, features may be enlarged for easy understanding, and the dimensional ratios of the components are not necessarily the same as actual ones.

An XYZ coordinate system is appropriately shown in each figure. The X-axis direction in 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 (+ Z side, one side) in the Z-axis direction is referred to as "upper side", and the negative side (-Z side, the other side) in the Z-axis direction is referred to as "lower side". The upper side and the lower side are directions for explanation only, and do not limit actual positional relationship and directions. Unless otherwise specified, a direction parallel to the central axis J (X-axis direction) is simply referred to as "axial direction" or "vertical direction", a radial direction about the central axis J is simply referred to as "radial direction", and a circumferential direction about the central axis J, that is, a direction around the central axis J is simply referred to as "circumferential direction". In the following description, the term "plan view" refers to a state 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 "outside in the vehicle width direction", and the-X side (right side in the drawing) may be referred to as "the other axial side", "the other side", or "inside in the vehicle width direction".

In addition, in the present specification, "extend in the axial direction" includes a case of extending in a direction inclined in a range of less than 45 ° with respect to the axial direction, in addition to a case of strictly extending in the axial direction (i.e., a direction parallel to the X axis). In the present specification, "extending along the central axis J" means extending in the axial direction around the central axis J. In addition, in the present specification, "extend in the radial direction" includes a case of extending in a direction inclined in a range of less than 45 ° with respect to the radial direction, in addition to a case of extending strictly in the radial direction, that is, a direction perpendicular to the axial 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 central axis J. Fig. 3 is a sectional view of the motor unit 2 of 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 sectional view of the motor unit 2 perpendicular to the central axis J.

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

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

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

The motor unit 10 is an electric motor as a power source of the in-wheel motor 1. The reducer unit 20 has an output shaft 29 that rotates about a central axis J extending in a direction perpendicular to the vertical direction. The speed reducer unit 20 reduces the rotation speed of the motor unit 10 and outputs the rotation speed from the output shaft 29. The output shaft 29 transmits the power of the motor unit 2 to the wheel 3. The case 40 houses the motor section 10, the reducer section 20, the pump section 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 central axis J. A center hole 50a is provided in the center of the hub carrier 50 in a plan view. The output shaft 29 is inserted through the center hole 50 a. In addition, a hub bearing 60 is located in the central bore 50 a. The hub carrier 50 rotatably supports the output shaft 29 via a hub bearing 60.

The hub carrier 50 has a bearing holding portion 51, an inclined portion 52, a hub carrier flange portion 53, and a pair of coupling portions (knuckles) 54. The bearing holding portion 51, the inclined portion 52, and the hub carrier 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 carrier flange portion 53 are arranged in this order from the radially inner side to the radially outer side.

The center hole 50a is provided at the center of the bearing holding portion 51 in a plan view. The bearing holding portion 51 is provided with a screw hole (not shown) to which a fixing screw 64 for fixing the outer ring 61 of the hub bearing 60 is fastened. That is, the hub carrier 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 holding portion 51. The inclined portion 52 is inclined toward the vehicle width direction inner side (the other axial side) as it goes toward the radial outer side. That is, the inclined portion 52 has a conical shape.

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

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

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

< hub bearing >

The hub bearing 60 is located inside the central hole 50a of the hub carrier 50. The hub bearing 60 supports the output shaft 29 rotatably 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 between the outer ring 61 and the inner ring 62.

The hub bearing 60 of the present embodiment is a double-row ball bearing. Therefore, 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 along 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 carrier 50. Specifically, the outer race 61 of the hub bearing 60 is detachably fixed to the bearing holding portion 51 of the hub carrier 50 by a fixing screw 64.

The inner race 62 of the hub bearing 60 holds the output shaft 29. An inner spline is provided on an inner peripheral surface 62c of the inner race 62. On the other hand, an outer spline is provided on an outer peripheral surface 29d of the output shaft 29. The inner race 62 is spline-coupled to the output shaft 29. This restricts the circumferential relative rotation of the inner race 62 and the output shaft 29. 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 part 62A and a 2 nd part 62B. The 1 st part 62A and the 2 nd part 62B are fixed to each other. The 1 st member 62A and the 2 nd member 62B are 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 one side) in the vehicle width direction with respect to the outer ring 61 of the hub bearing 60. The hub bearing flange 62a is provided with a plurality of screw holes 62b arranged in the circumferential direction. The screw hole 62b is fastened by a fixing screw 69, and the inner race 62, the wheel 3, and a disc rotor 72 of the brake portion 70 are fixed to each other by the fixing screw 69. That is, the wheel 3 and the disc rotor 72 are fixed to the inner race 62.

< housing >

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

The oil O is stored in the storage portion 49. The oil O is accumulated in the lower region of the housing 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 49 is provided with an oil passage 80 through which the oil O circulates in the housing 49. A pump section 30 is provided in a path of the oil passage 80.

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

The cylindrical 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 reducer portion 20 are housed radially inside the cylindrical 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 is plate-shaped extending in a direction perpendicular to the central axis J. The plurality of fixing plate portions 41b are arranged in the circumferential direction. Each fixing plate portion 41b is provided with a through hole 41c penetrating in the axial direction. That is, the housing 40 is provided with a plurality of through holes 41 c. A fixing screw 59 for fixing the housing 40 to the hub carrier 50 is inserted through the through hole 41 c. That is, the housing 40 is fixed to the hub carrier 50 at the fixing plate portion 41 b. In addition, the motor unit 2 is fixed to the hub carrier 50 at the housing 40.

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

As shown in fig. 3, the 1 st floor 42 covers the opening on the inside (the other axial side) in the vehicle width direction of the tubular member 41. The 1 st base plate 42 is a circular plate extending in a direction perpendicular to the axial direction with the center axis J as a center. The 1 st base plate 42 is provided with a base plate through hole 45 penetrating in the axial direction. The 1 st floor 42 has a 1 st surface 42a facing the inside in the vehicle width direction and a 2 nd surface 42b facing the outside 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 base plate 42 is provided with a pump accommodating recess 46 recessed in the axial direction. The bottom plate through hole 45 opens in the pump housing recess 46.

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

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

As shown in fig. 1, the 1 st base plate 42 is provided with a 1 st oil passage 81 penetrating therethrough. 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 casing 40. As described above, the oil O is stored in the storage portion 49. The oil O is accumulated in the lower region of the housing 49. The 1 st oil passage 81 introduces the oil O stored in the lower region of the housing 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 lid 44 is fixed to the 1 st surface 42a of the 1 st base plate 42. The cover 44 covers the opening of the pump housing recess 46 of the 1 st base plate 42. The pump chamber 31 of the pump section 30 is configured in a space surrounded by the inner wall surface of the pump housing recess 46 and the lid 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 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 with the center axis J as a center. The 2 nd base plate 43 is provided with a through insertion hole 48 penetrating in the axial direction. That is, the housing 40 is provided with a through-insertion hole 48 for connecting the inside and outside of the housing portion 49. The output shaft 29 is inserted through the insertion hole 48.

The 2 nd floor panel 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 base plate 43 is axially opposed to the hub carrier 50. The 2 nd surface 43b is provided with a ridge portion 43c projecting in the axial direction. The ridge portion 43c protrudes toward the hub carrier 50. The ridge portion 43c is annular and extends in the circumferential direction around the center axis J.

The raised strip portion 43c has a 2 nd fitting surface 43j facing radially outward. That is, the housing 40 has the 2 nd fitting surface 43 j. 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 the radial direction with respect to the hub carrier 50.

According to the present embodiment, the motor unit 2 is held from the radially outer side by the hub carrier 50 by fitting the 1 st fitting surface 53j to the 2 nd fitting surface 43 j. Therefore, the fixing strength of the motor unit 2 to the hub carrier 50 can be improved. Further, according to the present embodiment, the motor unit 2 can be easily aligned with respect to the hub carrier 50 by fitting the 1 st fitting surface 53j and the 2 nd fitting surface 43j, 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 through insertion 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 contacts the outer peripheral surface of the output shaft 29. The sealing member 6 is made of an elastic material such as rubber or elastomer resin. The seal member 6 prevents the oil O in the housing portion 49 from leaking to the outside through the insertion hole 48. Further, the seal member 6 suppresses entry of foreign matter into the housing portion 49 from the outside.

< Motor part >

The motor unit 10 includes a rotor 11 and an annular stator 17. The rotor 11 rotates about the center axis J. The stator 17 is located radially outside the rotor 11.

The stator 17 is held on the inner peripheral surface of the cylindrical 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 includes 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 19 b. That is, the stator 17 of the present embodiment is a 72-slot stator. 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 19b with an insulating member interposed therebetween. The insulating member (not shown) is made of resin and covers at least a part of the tooth portion 19b of the stator core 19. The insulating member insulates the teeth from the coil. A rotating magnetic field is generated in the stator 17 by the 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 another winding method may be employed.

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

The rotor 11 rotates about the center axis J. The rotor 11 includes an input shaft 12, a rotor holder 13, a rotor magnet 13a, and a rotor core 13 b.

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

The 1 st end portion 12a of the input shaft 12 is located on the vehicle width direction outer side (one axial side) with respect to the sun gear 21. The 1 st end 12a is housed in a recess (recessed portion) 29a, and the recess (recessed portion) 29a is provided in the output shaft 29.

The 2 nd end portion 12b of the input shaft 12 is located on the inner side (the other side in the axial direction) in the vehicle width direction with respect to the sun gear 21. The 2 nd end portion 12b is rotatably supported by a bearing member 4, and the bearing member 4 is held by the 1 st base plate 42. The 2 nd end portion 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 shaft 12A and the 2 nd shaft 12B are coupled 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 each 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 opened at both ends. As will be described later, the hollow portion 12c functions as a 2 nd oil passage (input shaft inner 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. Further, 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 a centrifugal force caused by the rotation of the rotor 11. The oil O flowing into the 3 rd oil passage 83 spreads radially outward from the radially outer opening of the 3 rd oil passage 83. The axial position of the 3 rd oil passage 83 is located inward in the vehicle width direction (on the other axial side) of 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. 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 is in the shape of a bottomed cylinder, and is open on the outside in the vehicle width direction (one axial side). 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 the axial position of one coil end 18b of the pair of coil ends 18a, 18 b.

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

The cylindrical portion 15 is cylindrical with the center axis J as the center. 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 inside (the other axial side) in the vehicle width direction of the cylindrical portion 15. The disc portion 14 closes the opening on the inside (the other axial side) in the vehicle width direction of the tubular portion 15. The disc portion 14 has a disc shape centered on the central axis J. The circular plate 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 a plan view. The outer peripheral surface of the 2 nd shaft 12B of the input shaft 12 is fitted into the fixing hole 14 h. That is, the rotor holder 13 is fixed to the input shaft 12 at the disc portion 14. Further, the shaft flange portion 12d of the input shaft 12 contacts the 2 nd surface 14 b. Thereby, the input shaft 12 is axially aligned with respect to the disc portion 14. The rotor holder 13 and the input shaft 12 may be indirectly fixed via another member.

The 1 st surface 14a of the disk portion 14 is provided with a resolver support portion 14c projecting in the axial direction. That is, the disc portion 14 has the resolver support portion 14 c. The resolver support portion 14c protrudes inward in the vehicle width direction (toward the other axial 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 end of the resolver support portion 14 c. 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 a rotation angle of the rotor 11 with respect to the housing 40.

According to the present embodiment, the resolver support portion 14c protruding in the axial direction and extending in the circumferential direction is provided in the circular plate portion 14, whereby the rigidity of the circular plate 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 is varied. According to the present embodiment, by suppressing the deformation of the disc 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 fixed by pressure contact 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 and the stator 17 are radially opposed to each other. 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 constituted by 12 sector magnets 13 aa. That is, the rotor magnet 13a has 12 sector magnets 13 aa. 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 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. Further, 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 reducer unit 20 inside the cylindrical portion 15. Therefore, the degree of freedom in the number of teeth of the gears (the sun gear 21, the planet gears 22, and the ring gear 23) constituting the reduction gear unit 20 is increased, and a more preferable reduction gear ratio can be realized. More specifically, the diameter of the planetary gear 22 can be increased to increase the number of teeth of the planetary gear 22, and the reduction ratio of the reduction gear unit 20 can be increased.

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

< bearing component >

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. Further, the outer ring of the bearing member 4 is fixed in a bearing holding recess 47 provided in the housing 40. The bearing member 4 supports the input shaft 12 at a position on the vehicle width direction inner side (the other side in the axial direction) than a connecting portion of 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 addition, when a material having high wear resistance is used as the housing 40 (more specifically, the 1 st base plate 42), the housing 40 itself may be used as a bearing in the housing 40.

< speed reducer part >

The speed reducer unit 20 is connected to the rotor 11 of the motor unit 10 to reduce the rotation speed of the rotor 11. The reduction gear unit 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 gears 22, the ring gear 23, the carrier pin 24, and the output shaft 29 constitute a planetary gear mechanism.

According to the present embodiment, the speed reducer section 20 constitutes a planetary gear mechanism, and therefore the input shaft 12 for inputting power and the output shaft 29 for outputting power can be arranged coaxially. This enables the motor unit 2 to be downsized.

In the present embodiment, the sun gear 21, the pinion gears 22, and the ring gear 23 are helical gears (helical gears). Therefore, when the reducer unit 20 operates, the sun gear 21, the pinion gears 22, and the ring gear 23 are subjected to stress in the axial direction from the gears that mesh with each other. 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 pinion gears 22 are subjected. In the present embodiment, when the vehicle is moving forward, the sun gear 21 and the ring gear 23 receive stress from the pinion gear 22 toward the inside in the vehicle width direction (the other side in the axial direction), and the pinion gear 22 receives stress from the sun gear 21 and the ring gear 23 toward the outside in the vehicle width direction (the one side in the axial direction). When the vehicle is driven backward, each gear receives stress in a direction opposite to the forward direction.

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, and may be provided on the outer periphery of the input shaft 12 by press-fitting a pinion gear of a separate member into the input shaft 12.

The plurality of planetary gears 22 are disposed radially outward of the sun gear 21. The planetary gear 22 rotates while meshing with the sun gear 21. The planetary gear 22 rotates about the rotation axis Jp. The planetary gear 22 revolves around the sun gear 21. The reducer unit 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. In addition, the number of the planetary gears 22 is not limited as long as the plurality of planetary gears 22 are provided in the speed reducer portion 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 22 a. The planetary gear 22 rotates about the carrier pin 24.

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

In contrast, the planetary gear 22 of the present embodiment is not a step gear. The planetary gears 22 mesh with the sun gear 21 and the ring gear 23 in 1 gear. Therefore, the sun gear 21, the pinion gears 22, and the ring gear 23 are axially overlapped with each other. By adopting such a structure, the axial dimension of the reducer portion 20 can be reduced.

The carrier pin 24 rotatably supports the planetary gear 22. The carrier pins 24 revolve 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 (cage and roller). However, the type of the bearing member 22b is not limited to this, and the bearing member 22b may be a needle bearing, for example.

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

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

The 2 nd pin inner oil passage 86 extends radially outward of the rotation axis Jp from the 1 st pin inner oil passage 85. The 2 nd pin inner oil passage 86 communicates the 1 st pin inner oil passage 85 with the outside of the carrier pin 24. The 2 nd pin internal oil passage 86 axially overlaps with the planetary gear 22. Therefore, the 2 nd pin internal oil passage 86 opens inside the gear center hole 22 a. In the present embodiment, 42 nd pin internal oil passages 86 are provided in the carrier pin 24. The 42 nd pin internal oil passages 86 are arranged at equal intervals in the circumferential direction of the rotation axis Jp.

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

The output shaft 29 supports the carrier pin 24. The output shaft 29 rotates about the central axis J with the revolution of the planetary gears 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 body portion 29A extending in the axial direction about the center axis J; and a carrier (flange portion) 25. The carrier 25 extends radially outward in a flange shape with respect to the output shaft body portion 29A. In the present embodiment, the output shaft body 29A and the carrier 25 are one member. However, the output shaft body 29A and the carrier 25 may be separate members coupled to each other.

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

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

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

The lid body portion 26a has a circular plate shape centered on the central axis J. The planetary gears 22 are disposed between the carrier 25 and the cover body 26a in the axial direction. When viewed from the axial direction, some of the teeth of the planetary gear 22 protrude radially outward from the carrier 25 and the cover body 26 a.

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

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

Axially, the 1 st thrust washers 22c are provided between the carrier 25 and the planetary gears 22 and between the cover main body portion 26a and the planetary gears 22, respectively. When the reduction gear unit 20 operates, the planet gears 22 are stressed in any direction in the 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 made smooth, 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 carrier 25 facing the inside in the vehicle width direction (the other side in the axial direction). That is, the carrier 25 is provided with a recess 29a that opens in the axial direction.

The recess 29a extends along the central axis J. The recess 29a is circular in plan view about the central axis J. The 1 st end 12a of the input shaft 12 is housed in the recess 29 a.

A 2 nd thrust washer 29c is provided between the bottom surface of the recess 29a and the 1 st end portion 12a of the input shaft 12. When the input shaft 12 rotates in a predetermined direction, the sun gear 21 receives stress from the planetary gears 22 in one axial direction. Accordingly, the 1 st end 12a of the input shaft 12 is pressed against the bottom surface of the recess 29 a. According to the present embodiment, the 2 nd thrust washer 29c is provided, so that the rotation of the input shaft 12 can be made smooth, and the wear of the end surface 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 circumferential surface of the recess 29 a. The groove portion 29b extends from the bottom surface of the recess portion 29a to the opening in the axial direction. The plurality of grooves 29b are arranged at equal intervals in the circumferential direction.

The carrier 25 is provided with a carrier internal oil passage 84 extending radially outward from the recess 29 a. The carrier internal oil passage 84 opens to the groove portion 29b at the inner peripheral surface of the recess portion 29 a. Further, the carrier internal oil passage 84 opens on the inner circumferential surface of the 1 st pin holding hole 25 a.

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

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

The ring gear 23 has a ring gear body portion 23a, a ring gear cylindrical portion 23b, and a ring gear flange portion 23 c. The ring gear main body portion 23a is annular. The inner peripheral surface of the ring gear main body portion 23a is provided with a tooth surface of a gear. The ring gear main body portion 23a is annular. The ring gear tubular portion 23b extends outward (one axial 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 tubular portion 23b on the outer side 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 23 d. The ring gear through hole 23d penetrates in the radial direction. Preferably, the ring gear through hole 23d overlaps the central axis J when viewed in the vertical 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 about the central axis J with the revolution of the planetary gears 22. The carrier 25 is fixed to the wheel 3 via the output shaft body portion 29A. Thus, the rotation of the 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 can reduce the thickness of the ring gear main body portion 23a in the radial direction, thereby reducing the weight of the motor unit 2.

In the present embodiment, at least a part of the sun gear 21, the pinion 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. Further, the in-wheel motor 1 can be thinned in the axial direction.

< Pump part >

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

The pump section 30 has 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 the pump storage recess 46 provided on the 1 st surface 42a of the 1 st base plate 42 and the lid 44 covering the opening of the pump storage recess 46. An O-ring 44a is provided between the cover 44 and the 1 st surface 42a of the 1 st base 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 central axis J passes through the pump chamber 31. The pump chamber 31 has a circular shape 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 through the outer peripheral surface. The other end of the connecting member 34 is fitted to the external gear central hole 32a of the external gear 32 through 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 portion 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 sectional view of the pump section 30 in a section perpendicular to the central 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 circumferential 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 with respect 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 an 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 therefore, a trochoid pump can be configured. Therefore, noise generated from the pump section 30 can be reduced, and the pressure and amount of the oil O discharged from the pump section 30 can be easily stabilized.

A 1 st pump internal oil passage 38 and a 2 nd pump internal oil passage 39 are provided in an inner wall surface of the pump chamber 31. The 1 st pump internal oil passage 38 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. Similarly, the 2 nd in-pump oil passage 39 is an oil passage provided in a groove portion of the bottom surface of the pump housing recess 46 and the facing surface of the lid portion facing the bottom surface. The 1 st pump inner oil passage 38 and the 2 nd pump inner oil passage 39 extend in an arc shape in the circumferential direction. The 1 st pump inner oil passage 38 and the 2 nd pump inner oil passage 39 are arranged in a circumferential direction. The 1 st pump internal oil passage 38 and the 2 nd pump internal 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 inner oil passage 39 is connected to the hollow portion 34a of the coupling member 34. That is, the 2 nd pump internal oil passage 39 is connected to the 2 nd oil passage 82.

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

Pump outlet 36 is provided at a boundary portion between pump-2 internal oil passage 39 and pump-2 oil passage 82. The pump outlet 36 discharges 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 about the center axis J. Thereby, the internal gear 33 meshing with the external gear 32 rotates around the rotation axis Jt. In addition, the portion where the gap between the external gear 32 and the internal gear 33 is widened moves around the central axis J. The oil O sucked into the pump chamber 31 from the suction port 35 is sent 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 section 30 is driven via the input shaft 12.

According to the present embodiment, the pump section 30 is driven by the rotation of the input shaft 12, the oil O is sucked from the lower region of the housing section 49, and the oil O circulates in the oil passage 80. Therefore, an external power supply is not required to drive the pump section 30. Further, by circulating the oil O in the housing portion 49, the lubricity of the gears 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 about 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 at a negative pressure, and as a result, the suction of the oil O by the pump section 30 is promoted. Therefore, even when the pump section 30 is downsized, the pump section 30 can be made to have a sufficient suction force. According to the present embodiment, the pump section 30 can be downsized, and the motor unit 2 can be downsized.

< oil passage >

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

The oil passage 80 includes a 1 st oil passage 81, a 2 nd oil passage 82, a 3 rd oil passage 83, a carrier internal oil passage 84, a 1 st pin internal oil passage 85, a 2 nd pin internal oil passage 86, and a 3 rd pin internal 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 liquid 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 prevent the oil O from acting as resistance to the rotation of the rotor 11. The opening of the 1 st oil passage 81 in the housing portion 49 is located below the lower limit of the liquid level of the oil O.

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 section 30 is driven, the oil O accumulated in the lower region of the housing section 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 a 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 outer end (one axial side) in the vehicle width direction of the 2 nd oil passage 82.

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 scatters 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 portion 49 by the centrifugal force of the input shaft 12. This can improve the lubricity of each part in the housing 49, and can cool the motor unit 10 with the oil O.

The axial position of the 3 rd oil passage 83 overlaps with the axial position of one of the pair of coil ends 18a, 18b (the 1 st coil end 18a in the present embodiment). 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 positioned between the radially outer opening of the 3 rd oil passage 83 and the 1 st coil end 18 a. 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.

Further, 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 portion 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 portion 12a of the input shaft 12 is housed in a recess 29a provided in the output shaft 29. Therefore, the 2 nd oil passage 82 opens inside the recess 29 a. The oil O flows into the recess 29a from the 2 nd oil passage 82.

The oil O flowing into the recess 29a is supplied to the 2 nd thrust washer 29c housed in the recess 29 a. This improves the lubricity between the 2 nd thrust washer 29c and the end surface of the input shaft 12, and allows the input shaft 12 to rotate more smoothly.

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

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

Further, a part of the oil O flowing into the recess 29a moves in the axial direction and flows out from the opening of the recess 29 a. Part of the oil O flowing out of the opening of the recess 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 planetary gears 22 improves the lubricity of the 2 nd thrust washer 29c interposed between the carrier 25 and the planetary gears 22.

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

According to the present embodiment, the carrier internal oil passage 84 and the 3 rd pin internal 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 internal oil passage 85 by the centrifugal force accompanying the rotation of the output shaft 29.

A part of the oil O flowing into the 1 st pin inner oil passage 85 is guided to the outer peripheral surface of the carrier pin 24 via the 2 nd pin inner 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 lubricating property of the bearing member 22b can be improved by supplying the oil O to the bearing member 22 b. 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. Then, the oil O flows radially outward and is supplied to the tooth surfaces of the pinion gears 22 and the ring gear 23.

A part of the oil O flowing into the 1 st pin inner oil passage 85 flows out from the 1 st pin inner oil passage 85 at the opening in the 1 st pin inner oil passage 85 in the axial direction and scatters radially outward. The ring gear 23 is disposed radially outward of the carrier pin 24. Therefore, the oil O scattered from the 1 st pin internal 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 pinion 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 the lubricity of the meshing between the ring gear 23 and the pinion gear 22, and can also improve the lubricity of the meshing between the pinion gear 22 and the sun gear 21. This can improve the transmission efficiency among the sun gear 21, the pinion gears 22, and the ring gear 23. Further, wear of the sun gear 21, the pinion gears 22, and the ring gear 23 can also be suppressed.

The oil O that has reached the ring gear 23 is accumulated in the lower region on the radially inner side 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 radially inner side of the ring gear 23 moves to the lower region of the housing portion 49 provided in the housing 40 through the ring gear through hole 23 d. According to the present embodiment, the ring gear through hole 23d is provided, whereby circulation of the oil O in the housing portion 49 can be promoted, and the oil O can be effectively used.

Preferably, the ring gear through hole 23d overlaps the central axis J when viewed in the vertical direction. The ring gear 23 extends in the circumferential direction around the center axis J. Therefore, the lowermost 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 in the vertical direction, the ring gear through-hole 23d can be positioned at the lowermost point of the inner peripheral surface of the ring gear 23. This enables the oil O on the radially inner side of the ring gear 23 to be efficiently discharged.

As shown in fig. 3, the cylindrical portion 15 of the rotor holder 13 is located radially outward of the planetary gears 22. Therefore, a part of the oil O scattered radially outward of the planetary gear 22 via the 1 st pin internal oil passage 85 is captured by the inner circumferential surface of the cylindrical portion 15. The oil O trapped on the inner circumferential 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 with 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 collected again to the lower region of the receiver 49.

< brake part >

As shown in fig. 2, the brake portion 70 has a disc 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 72 b. The tray main body portion 72a and the bracket portion 72b are fixed to each other by a fixing screw 72 c.

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

The bracket portion 72b has an annular plate shape centered on the central axis J. The bracket portion 72b is tapered so as to incline inward in the vehicle width direction (toward the other axial side) as it goes radially outward. A screw hole 72f to which the fixing screw 72c is fastened is provided at a radially outer end of the bracket portion 72 b.

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

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

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

The pair of brake pads 71b are fixed to the inner wall surfaces of the slits 71 c. The pair of brake pads 71b axially face each other with the disc main body 72a interposed therebetween.

The brake pad 71b is pushed out by the disc caliper main body portion 71a in a direction toward the disc main body portion 72 a. As a result, the brake pad 71b comes into contact with the surface of the disk main body 72a facing in the axial direction, and brakes the disk main body 72 a. That is, the pair of brake pads 71b sandwich the disc rotor 72.

In fig. 2, for the sake of easy understanding, the axial gap between the disc main body portion 72a and the brake pad 71b is shown 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 located between the disc rotor 72 and the motor unit 2 in the axial direction.

< wheel >)

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

The wheel 3 is connected to an output shaft 29 of the reduction gear unit 20.

The rotation of the rotor 11 of the motor unit 10 is transmitted to the wheel 3 via the reduction gear unit 20. The wheel 3 holds a tire, not shown, at the rim portion 3 a. The wheels 3 transmit power to a road surface via tires.

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

An end portion of the motor unit 2 on the vehicle width direction outer side (one axial side) is positioned on the vehicle width direction outer side (one axial side) with respect to an end portion of the rim portion 3a on the vehicle width direction inner side (the other axial side). 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 inside the wheel 3, it is possible to suppress these components from protruding largely inward in the vehicle width direction, and to improve the degree of freedom in designing the vehicle.

An end portion of the motor unit 2 on the inside in the vehicle width direction (the other side in the axial direction) is positioned on the inside in the vehicle width direction (the other side in the axial direction) with respect to an end portion of the rim portion 3a on the inside 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 the in-wheel motor 1 is driven, the vehicle having the in-wheel motor starts running. According to the present embodiment, the motor unit 2 is exposed from the wheel 3, and therefore, when the vehicle travels, a relative air flow (wind) with respect to the housing 40 is generated outside the housing 40, thereby cooling the housing 40. Accordingly, the stator core 19 held by the case 40 and the oil O in the case 40 are cooled.

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

The fixed portion 3c is located at the center of the wheel 3 in plan view. The fixing portion 3c has an annular plate shape centered on the central axis J. The fixed 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 race 62 of the hub bearing 60 and the disc rotor 72 at the fixing portion 3 c. Further, the inner race 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.

< arrangement of parts >

Next, the arrangement of the characteristic components 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 side in the axial direction) with respect to the hub carrier 50. That is, the motor unit 2 and the hub carrier 50 axially face each other. In addition, the motor unit 2 is fixed to the hub carrier 50 at the housing 40. The hub bearing 60 that rotatably holds the output shaft 29 of the motor unit 2 is held by the hub carrier 50 inside the center hole 50a of the hub carrier 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 to the hub carrier 50. Therefore, even in a state where the in-wheel motor 1 is mounted on a vehicle and is in contact with the ground via a 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 facilitated.

According to the present embodiment, as shown in fig. 1, the housing 40 is provided with the through hole 41c, and the hub carrier 50 is provided with the screw hole 53 a. The housing 40 is fixed to the hub carrier 50 by fastening the fixing screws 59 inserted through the through holes 41c to the screw holes 53 a. Therefore, the head of the fixing screw 59 is turned by a wrench or the like on the side where the motor unit 2 is arranged with respect to the hub carrier 50. That is, the head of the fixing screw 59 and the motor unit 2 are located in the same direction with respect to the hub carrier 50. The worker does not need to move to the opposite side of the hub carrier 50 after removing the fixing screw 59 in the attachment work and the detachment work of the motor unit 2. 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 to 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 screws 59 are removed, the entire motor unit 2 is moved inward in the vehicle width direction, whereby the motor unit 2 can be easily detached from the in-wheel motor. Therefore, maintenance of the motor unit 2 is easily performed.

According to the present embodiment, as shown in fig. 3, the 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 portion 49. The sealing of the housing 49 is completed only in 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 is maintained, and the oil O is prevented from flowing out of the housing portion 49.

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 fixed portion 3c with respect to the hub carrier 50. That is, the motor unit 2 is positioned on the vehicle width direction inner side (the other axial side) with respect to the hub carrier 50, and the fixed portion 3c is positioned on the vehicle width direction outer side (the one axial side). Therefore, in the present embodiment, when the motor unit 2 is detached, the wheel 3 does not need to be detached, and thus 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 positioned on the vehicle width direction inner side (the other axial side) with respect to the hub carrier 50, and the disc rotor 72 is positioned on the vehicle width direction outer side (the one axial side). Therefore, in the present embodiment, when the motor unit 2 is detached, the disk rotor 72 does not need to be detached, and thus the motor unit 2 is easily detached. Similarly, when the disc rotor 72 is removed, the motor unit 2 does not need to be removed, and therefore the disc rotor is easily removed. Therefore, maintenance of the disc rotor 72 is easily performed.

While the embodiments of the present invention have been described above, the respective configurations and combinations thereof in the embodiments are examples, and additions, omissions, substitutions, and other modifications of the configurations can be made without departing from the scope of the present invention. The present invention is not limited to the embodiments.

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

In the motor unit described above, an example is given in which an output shaft that outputs power of the motor unit is connected to a planetary gear. However, the output shaft may be connected to the ring gear.

For example, the motor unit of the above embodiment is not limited to a vehicle, and can be widely used for various types of equipment having wheels, such as a robot, such as an unmanned carrier, an agricultural implement, or a cleaning robot.

Description of the reference symbols

1: an in-wheel motor; 2: a motor unit; 3: a wheel; 3 a: a rim portion; 3c, 26 b: a fixed part; 3d, 41c, 72d, 72 e: a through hole; 4: a bearing member (1 st bearing member); 6: a sealing member; 9: a vehicle; 10: a motor section; 11: a rotor; 12: an input shaft; 12 a: 1 st end part; 12 b: a 2 nd end portion; 13: a rotor holder; 13 a: a rotor magnet; 13 c: a retaining hole; 14: a circular plate portion; 14 b: the 2 nd face (bottom face); 15: a cylindrical portion; 17: a stator; 18: a coil; 18a, 18 b: a coil end; 19: a stator core; 20: a speed reducer section; 21: a sun gear; 22: a planetary gear; 22 a: a gear central bore; 22 b: a bearing member; 22 c: 1 st thrust washer; 23: a ring gear; 23 d: a gear ring through hole; 24: a carrier pin; 25: a gear carrier; 25 a: 1 st pin holding hole (pin holding hole); 29: an output shaft; 29 a: a recess; 29 b: a groove part; 29 c: a 2 nd thrust washer; 29 d: an outer peripheral surface; 30: a pump section; 31: a pump chamber; 32: an outer gear; 33: an internal gear; 35: a suction inlet; 36: an outlet of the pump; 40: a housing; 43 j: a 2 nd fitting surface; 48: a through insertion hole; 49: a storage section; 50: a hub carrier; 50 a: a central bore; 53a, 62b, 72 f: a threaded hole; 53 j: the 1 st fitting surface; 59. 64, 69, 72 c: a set screw; 60: a hub bearing; 61: an outer ring; 62: an inner ring; 62c, the ratio of: an inner peripheral surface; 63: a rolling body; 70: a brake section; 71: a disc caliper; 71 b: a brake pad; 72: a disc rotor; 80: an oil path; 81: the 1 st oil path; 82: a 2 nd oil passage; 82: the 2 nd oil path (the input shaft inner oil path); 83: a 3 rd oil path; 83: a 3 rd oil passage (input shaft inner radial oil passage); 84: an oil path in the gear carrier; 85: the 1 st pin inner oil way; 86: the 2 nd pin internal oil way; 87: the 3 rd pin internal oil way; j: a central axis; o: and (3) oil.

Claims (8)

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

the in-wheel motor includes:

a motor unit having an output shaft that rotates around a central axis and outputting power from the output shaft;

a hub carrier that extends along a plane perpendicular to the center axis, is fixed to the vehicle, and is provided with a center hole through which the output shaft is inserted;

a hub bearing that is held by the hub carrier inside the center hole and that supports the output shaft rotatably with respect to the hub carrier; and

a wheel fixed to the output shaft,

the motor unit has:

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

a speed reducer unit that reduces the rotation of the rotor and outputs the rotation from the output shaft; and

a case that houses the motor unit and the reducer unit,

the motor unit is axially opposed to the hub carrier and is fixed to the hub carrier at the housing.

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

a plurality of screw holes arranged along the circumferential direction and extending along the axial direction are arranged on the hub carrier,

the housing is provided with a plurality of through holes through which a plurality of fixing screws fastened to the screw holes are inserted.

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

a spline is arranged on the outer peripheral surface of the output shaft,

and the output shaft is in spline combination with the inner ring of the hub bearing.

4. The in-wheel motor according to any one of claims 1 to 3,

the wheel has:

a rim portion that holds a tire; and

a fixing portion fixed to the output shaft,

the fixing portion is located on an axially opposite side of the motor unit with respect to the hub carrier.

5. The in-wheel motor according to any one of claims 1 to 4,

the in-wheel motor has a brake part,

the brake unit includes:

a disc caliper fixed to the hub carrier; and

a disc rotor fixed to the wheel,

the disc caliper has a pair of brake pads sandwiching the disc rotor,

the disc rotor is located on an axially opposite side of the motor unit with respect to the hub carrier.

6. The in-wheel motor according to any one of claims 1 to 5,

the speed reducer unit includes:

a sun gear fixed to the rotor of the motor unit;

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

a ring gear disposed radially outward of the plurality of pinion gears and meshing with the plurality of pinion gears;

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

and a carrier that holds the plurality of carrier pins.

7. The in-wheel motor according to any one of claims 1 to 6,

the hub carrier has a 1 st fitting surface extending in a circumferential direction and facing radially inward,

the housing has a 2 nd fitting surface that is fitted to the 1 st fitting surface, and the 2 nd fitting surface extends in the circumferential direction and faces radially outward.

8. The in-wheel motor according to any one of claims 1 to 7,

the housing is provided with a through-insertion hole through which the output shaft is inserted,

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

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