WO2019124242A1

WO2019124242A1 - In-wheel motor

Info

Publication number: WO2019124242A1
Application number: PCT/JP2018/046072
Authority: WO
Inventors: 山口　康夫; 久嗣藤原; 中村　圭吾
Original assignee: 日本電産株式会社
Priority date: 2017-12-18
Filing date: 2018-12-14
Publication date: 2019-06-27
Also published as: CN111465522A

Abstract

One aspect of this in-wheel motor is provided with: a motor unit that has an output shaft which rotates about the center axis, so as to output motive power from the output shaft; a hub carrier that extends along a plane orthogonal to the center axis, that is provided with a center hole in which the output shaft is inserted, and that is fixed to a vehicle; a hub bearing that is held, inside the center hole, by the hub carrier so as to support the output shaft in a rotatable manner with respect to the hub carrier; and a wheel that is fixed to the output shaft. The motor unit includes: a motor part including a rotor that rotates about the center axis and an annular stator that is positioned radially outside the rotor; a decelerator part that decelerates rotation of the rotor and outputs the decelerated rotation from the output shaft; and a case accommodating the motor part and the decelerator part. The motor unit is opposed, in the axial direction, to the hub carrier, and is fixed to the hub carrier inside the case.

Description

In-wheel motor

The present invention relates to an in-wheel motor. This application claims the benefit of US Provisional Application No. 62 / 599,870, filed Dec. 18, 2017, US Provisional Application No. 62 / 627,287, filed Feb. 7, 2018, and 2018 3, Priority is claimed on the basis of Japanese Patent Application No. 2018-070049 filed on May 30, the content of which is incorporated herein by reference.

Japanese Patent Laid-Open Publication No. 2017-159883 discloses an in-wheel motor provided with a motor unit for directly driving the wheel in the wheel.

Japanese Patent Publication: JP-A-2017-159883

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

SUMMARY OF THE INVENTION In view of the above-described problems, one aspect of the present invention aims to provide an in-wheel motor in which the motor unit can be easily attached and detached.

One aspect of the in-wheel motor according to the present invention is an in-wheel motor mounted on a vehicle, comprising: a motor unit having an output shaft rotating about a central axis and outputting power from the output shaft; A hub carrier is provided which extends along an orthogonal plane and through which the output shaft is inserted and which is fixed to the vehicle, and which is held by the hub carrier inside the central hole and against the hub carrier. A hub bearing that rotatably supports the transmission shaft, and a wheel fixed to the output shaft. The motor unit includes a motor unit having a rotor that rotates around a central axis and an annular stator that is located radially outward of the rotor, and a reduction gear unit that decelerates the rotation of the rotor and outputs it from the output shaft. And a case for housing the motor unit and the reduction gear unit. The motor unit is axially opposed to the hub carrier and fixed to the hub carrier in the case.

According to one aspect of the present invention, an in-wheel motor is provided that facilitates the attachment and detachment of the motor unit.

FIG. 1 is a cross-sectional view along the XZ plane of the in-wheel motor of one embodiment. FIG. 2 is a cross-sectional view taken along an XY plane of the in-wheel motor of one embodiment. FIG. 3 is a cross-sectional view along the central axis J of the motor unit of one embodiment. FIG. 4 is a cross-sectional view orthogonal to the central axis J of the motor unit of one embodiment. FIG. 5 is a cross-sectional view of a pump portion of an embodiment.

Hereinafter, with reference to the drawings, an in-wheel motor and a motor unit provided in the in-wheel motor according to an embodiment of the present invention will be described. In the drawings used in the following description, in order to make the features easy to understand, the features that are the features may be enlarged for the sake of convenience, and the dimensional ratio of each component may be limited to the same as the actual Absent.

In each figure, an XYZ coordinate system is shown as appropriate. The X-axis direction of each drawing is a direction parallel to the axial direction of the central axis J shown in FIG. 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, other side) as “lower side”. Call. Note that the upper and lower sides are directions used merely for the purpose of explanation, and do not limit the actual positional relationship or direction. Further, unless otherwise noted, a direction (X-axis direction) parallel to the central axis J is simply referred to as “axial direction” or “vertical direction”, and a radial direction centered on the central axis J is simply referred to as “radial direction”. The circumferential direction around the central axis J, that is, around the axis of the central axis J, is simply referred to as “circumferential direction”. Furthermore, in the following description, “plan view” means a state viewed from the axial direction.

In the following description, the direction in which the central axis J extends is taken as the axial direction. The central axis J coincides with the width direction of the vehicle. Further, in the following description, the + X side (left side in the figure) is referred to as “axial side”, “one side” or “vehicle width direction outer side”, and the −X side (right side in the figure) is “axial side other side It may be called "other side" or "vehicle width direction inner side."

Furthermore, in the present specification, “extending along the axial direction” means a range of less than 45 ° with respect to the axial direction in addition to the case of extending in the axial direction (that is, the direction parallel to the X axis) It also includes the case of extending in the inclined direction. In the present specification, “extending along the central axis J” means extending axially around the central axis J. Furthermore, in the present specification, “extend in the radial direction” means in the range of less than 45 ° with respect to the radial direction, in addition to the case of extending in the radial direction strictly, that is, perpendicular to the axial direction It also includes the case of extending in an inclined direction.

<In-wheel motor>
1 and 2 are cross-sectional views taken along the central axis J of the in-wheel motor 1 of the present embodiment. FIG. 3 is a cross-sectional view taken along the central axis J of the motor unit 2 provided in the in-wheel motor 1. FIG. 1 is a cross-sectional view taken along the XZ plane, and FIGS. 2 and 3 are cross-sectional views taken along the XY plane. FIG. 4 is a cross-sectional view orthogonal to the central axis J of the motor unit 2.

As shown in FIG. 1, the in-wheel motor 1 of the present embodiment is attached to, for example, a vehicle 9 of an ordinary automobile. However, in-wheel motor 1 may be attached to vehicles, 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 has a motor unit 10, a reduction gear unit 20, a bearing member (first bearing member) 4, a resolver 5, a pump unit 30, oil O and a case 40. That is, the in-wheel motor 1 includes a motor unit 10, a reduction gear unit 20, a bearing member 4, a pump unit 30, oil O and a case 40.

The motor unit 10 is an electric motor serving as a power source of the in-wheel motor 1. The reduction gear unit 20 has an output shaft 29 which rotates around a central axis J extending along a direction perpendicular to the vertical direction. The reduction gear unit 20 decelerates the rotation of the motor unit 10 and outputs it from the output shaft 29. The output shaft 29 transmits the power of the motor unit 2 to the wheel 3. The case 40 accommodates the motor unit 10, the reduction gear unit 20, the pump unit 30, and the oil O.

<Hub carrier>
The hub carrier 50 extends along a plane orthogonal to the central axis J. The hub carrier 50 is a disk-like member centered on the central axis J. A central hole 50 a is provided at the center of the hub carrier 50 in plan view. The output shaft 29 is inserted into the central hole 50a. Also, the hub bearing 60 is located in the central hole 50a. 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 connection portions (knuckles) 54. The bearing holding portion 51, the inclined portion 52, and the hub carrier flange portion 53 are connected to one another to form a disk 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 outer side.

The center hole 50 a described above is provided at the center of the bearing holder 51 in a plan view. The bearing holding portion 51 is provided with a screw hole (not shown) in 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 in the bearing holder 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 inner side in the vehicle width direction (the other side in the axial direction) as it goes radially outward. That is, the inclined portion 52 is conical.

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 53 a 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 along the circumferential direction. Fixing screws 59 for fixing the case 40 of the motor unit 2 to the hub carrier 50 are fastened to the plurality of screw holes 53 a.

The hub carrier flange portion 53 has a first fitting surface 53 j facing inward in the radial direction at a connection portion with the inclined portion 52. The first fitting surface 53j extends along the circumferential direction. As will be described later, the first fitting surface 53 j is fitted to the second fitting surface 43 j of the case 40.

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

<Hub bearing>
The hub bearing 60 is located inside the central hole 50 a of the hub carrier 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 positioned between the outer ring 61 and the inner ring 62.

The hub bearing 60 of the present embodiment is a double row ball bearing. For this reason, 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 and in the circumferential direction. However, the hub bearing 60 may be a bearing member of another configuration.

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

The inner ring 62 of the hub bearing 60 holds the output shaft 29. The inner peripheral surface 62 c of the inner ring 62 is provided with a female spline. On the other hand, male splines are provided on the outer peripheral surface 29 d of the output shaft 29. The inner ring 62 and the output shaft 29 are splined. Thereby, relative rotation of the inner ring 62 and the output shaft 29 in the circumferential direction is limited. That is, the inner ring 62 rotates with the output shaft 29.

The inner ring 62 of the hub bearing 60 has a first member 62A and a second member 62B. The first member 62A and the second member 62B are fixed to each other. The first member 62A and the second member 62B are disposed radially inward of different rolling elements 63, and the rolling elements 63 are in contact with each other.

As shown in FIG. 2, the first member 62A of the inner ring 62 has a hub bearing flange portion (wheel attachment portion) 62a extending radially outward. The hub bearing flange portion 62 a extends to the outer side (axially one side) of the outer ring 61 of the hub bearing 60 in the vehicle width direction. The hub bearing flange portion 62a is provided with a plurality of screw holes 62b aligned in the circumferential direction. Fixing screws 69 for fixing the inner ring 62, the wheel 3 and the disc rotor 72 of the brake unit 70 to each other are fastened to the screw holes 62b. That is, the wheel 3 and the disk rotor 72 are fixed to the inner ring 62.

<Case>
As shown in FIG. 1, the case 40 is located inward in the vehicle width direction (the other side in the axial direction) with respect to the hub carrier 50. The case 40 is fixed to the vehicle 9 via the hub carrier 50. The case 40 has a housing portion 49 for housing the motor portion 10, the reduction gear portion 20, and the pump portion 30.

The oil O is stored in the storage unit 49. The oil O accumulates 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 vertical center (that is, the central axis J) of the housing portion 49.

In the housing portion 49, an oil passage 80 for circulating the oil O in the housing portion 49 is provided. A pump unit 30 is provided in the path of the oil passage 80.

As shown in FIG. 3, the case 40 includes a cylindrical member 41, a first bottom plate 42, a second bottom plate 43, a lid 44, and the sealing member 6. The housing portion 49 is a space surrounded by the cylindrical member 41, the first bottom plate 42 and the second bottom plate 43.

The cylindrical member 41 has a cylindrical shape centered on the central axis J. The cylindrical member 41 extends along the axial direction. The cylindrical member 41 opens in the axial direction on both sides. Inside the radial direction of the cylindrical member 41, the motor unit 10 and the reduction gear unit 20 are accommodated.

As shown in FIG. 1, the cylindrical member 41 has a plurality of fixing plate portions 41 b protruding outward in the radial direction. The fixed plate portion 41 b has a plate shape extending in a direction orthogonal to the central axis J. The plurality of fixing plates 41 b are arranged along the circumferential direction. Each fixing plate portion 41 b is provided with a through hole 41 c penetrating in the axial direction. That is, the case 40 is provided with a plurality of through holes 41 c. Fixing screws 59 for fixing the case 40 to the hub carrier 50 are inserted into the through holes 41 c. That is, the case 40 is fixed to the hub carrier 50 at the fixing plate portion 41 b. The motor unit 2 is fixed to the hub carrier 50 in the case 40.

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

As shown in FIG. 3, the first bottom plate 42 covers the opening on the inner side (the other side in the axial direction) of the tubular member 41 in the vehicle width direction. The first bottom plate 42 is a disk extending in a direction orthogonal to the axial direction with the central axis J as a center. The first bottom plate 42 is provided with a bottom plate through hole 45 penetrating in the axial direction. Further, the first bottom plate 42 has a first surface 42 a facing inward in the vehicle width direction and a second surface 42 b facing outward in the vehicle width direction. The second surface 42 b constitutes a part of the inner wall surface of the housing portion 49.

The first surface 42 a of the first bottom plate 42 is provided with a pump receiving recess 46 which is recessed in the axial direction. A bottom plate through hole 45 opens in the pump housing recess 46.

The second surface 42 b of the first bottom plate 42 is provided with a bearing holding recess 47 which is recessed in the axial direction. A bottom plate through hole 45 opens in the bearing holding recess 47. The bearing holding recess 47 holds the bearing member 4 that rotatably supports the input shaft 12 of the motor unit 10.

The second surface 42b of the first bottom plate 42 is provided with a resolver stator pedestal 42c that protrudes in the axial direction. That is, the case 40 has a resolver stator pedestal 42c. The resolver stator base 42c extends along the circumferential direction. The resolver stator 5a is screwed to the resolver stator pedestal 42c.

As shown in FIG. 1, the first bottom plate 42 is provided with a first oil passage 81 penetrating the inside. That is, the first oil passage 81 is provided in the case 40. The first oil passage 81 extends upward from the lower region of the housing portion 49 of the case 40. As described above, the oil O is stored in the storage unit 49. The oil O accumulates in the lower region of the housing 49. The first oil passage 81 introduces the oil O accumulated in the lower region of the housing portion 49 into the suction port 35 of the pump chamber 31. That is, the first oil passage 81 connects the lower region of the housing portion 49 and the suction port 35.

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

The second bottom plate 43 covers the opening on the outer side (axial direction one side) of the cylindrical member 41 in the vehicle width direction. The second bottom plate 43 is a disk extending in a direction orthogonal to the axial direction with the central axis J as a center. The second bottom plate 43 is provided with an insertion hole 48 penetrating in the axial direction. That is, in the case 40, an insertion hole 48 connecting the inside and the outside of the housing portion 49 is provided. The output shaft 29 is inserted into the insertion hole 48.

The second bottom plate 43 has a first surface 43a facing inward in the vehicle width direction and a second surface 43b facing outward in the vehicle width direction. The first surface 43 a of the second bottom plate 43 constitutes an inner wall surface of the housing portion 49.

As shown in FIG. 1, the second surface 43 b of the second bottom plate 43 axially faces the hub carrier 50. The second surface 43 b is provided with a protruding portion 43 c that protrudes in the axial direction. The ridges 43 c protrude toward the hub carrier 50. The ridges 43c are annular in shape and extend circumferentially about the central axis J.

The ridge portion 43c has a second fitting surface 43j that faces radially outward. That is, the case 40 has the second fitting surface 43j. The second fitting surface 43j extends along the circumferential direction. The second fitting surface 43 j fits in a first fitting surface 53 j provided on the hub carrier 50. Thereby, the case 40 is positioned in the radial direction with respect to the hub carrier 50.

According to the present embodiment, the hub carrier 50 holds the motor unit 2 from the outer side in the radial direction by the fitting of the first fitting surface 53 j and the second fitting surface 43 j. Therefore, the strength of fixing the motor unit 2 to the hub carrier 50 can be increased. In addition, according to the present embodiment, the motor unit 2 can be easily aligned with the hub carrier 50 by fitting the first fitting surface 53 j and the second fitting surface 43 j. 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 insertion hole 48 and the outer peripheral surface of the output shaft 29. The seal member 6 has an annular shape in a plan view. The seal member 6 is fixed to the inner peripheral surface of the insertion hole 48 of the second bottom plate 43. The inner end of the seal member 6 contacts the outer peripheral surface of the output shaft 29. The seal member 6 is made of an elastic material such as rubber or elastomeric resin. The seal member 6 prevents the oil O in the housing portion 49 from leaking out of the insertion hole 48. In addition, the seal member 6 suppresses the entry of foreign matter into the housing portion 49 from the outside.

<Motor section>
The motor unit 10 has 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 on the inner peripheral surface of the cylindrical member 41 of the case 40. The stator 17 faces the rotor magnet 13 a of the rotor 11 in the radial direction.
The stator 17 has 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 portion 19 a and a plurality of teeth portions 19 b extending inward in the radial direction from the core back portion 19 a. The stator core 19 is configured by laminating laminated steel plates along the axial direction.

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

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

As shown in FIG. 3, the coil 18 has a pair of coil ends 18 a and 18 b that respectively project on both sides in the axial direction with respect to the stator core 19. In the present embodiment, of the pair of coil ends 18a and 18b, the one located on the inner side in the vehicle width direction (the other side in the axial direction) is referred to as the first coil end 18a, and on the outer side in the vehicle width direction (one side in the axial direction). The one located is called the second coil end 18b.

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

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

The first end 12 a of the input shaft 12 is located outside the sun gear 21 in the vehicle width direction (one side in the axial direction). The first end 12 a is accommodated in a recess 29 a provided in the output shaft 29.

The second end 12 b of the input shaft 12 is positioned inward in the vehicle width direction (the other side in the axial direction) with respect to the sun gear 21. The second end 12 b is rotatably supported by the bearing member 4 held by the first bottom plate 42. The second end 12 b is supported by the case 40 via the bearing member 4.

The input shaft 12 has a first shaft 12A and a second shaft 12B. The first shaft 12A and the second shaft 12B are connected to each other.

The first shaft 12 </ b> A is located on the first end 12 a side of the input shaft 12. Further, the above-described sun gear 21 is provided on the outer peripheral surface of the first shaft 12A. The second shaft 12 B is located on the second end 12 b side of the input shaft 12. The input shaft 12 is supported by the bearing member 4 at the second shaft 12B.

The first shaft 12A and the second shaft 12B are both hollow shafts centered on the central axis J. The hollow portion of the first shaft 12A and the hollow portion of the second 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 the hollow portion 12 c extending along the axial direction and opening at both ends. As described later, the hollow portion 12 c functions as a second oil passage (an oil passage in the input shaft) 82 which is a part of the oil passage 80. That is, the second oil passage 82 extends in the axial direction inside the input shaft 12.

The second shaft 12B has a radially outwardly extending shaft flange portion 12d. The second shaft 12B is provided with a third oil passage (input shaft radial direction oil passage) 83 extending radially outward from the hollow portion 12c (that is, the second oil passage 82).

The third oil passage 83 brings the second oil passage 82 into communication with the outside of the input shaft 12. Part of the oil O flowing through the second oil passage 82 flows into the third oil passage 83 by the centrifugal force accompanying the rotation of the rotor 11. The oil O that has flowed into the third oil passage 83 is diffused radially outward from the radially outer opening of the third oil passage 83. The axial position of the third oil passage 83 is on the inner side in the vehicle width direction (the other side in the axial direction) than the axial position of the cylindrical portion 15 of the rotor holder 13. That is, the third oil passage 83 is located on the opposite side of the cylindrical portion 15 with respect to the disc portion 14. Further, the radial outer opening of the third oil passage 83 faces the first coil end 18a in the radial direction.

The rotor holder 13 holds the input shaft 12, the rotor core 13b and the rotor magnet 13a. The rotor holder 13 is cylindrical with a bottom, and opens to the outer side in the vehicle width direction (one side in the axial direction). The axial position of the opening of the rotor holder 13 overlaps the axial position of the second coil end 18b. 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 and 18b.

The rotor holder 13 has a disc portion 14 that spreads in the radial direction, and a cylindrical tubular portion 15 located at the radially outer end of the disc portion 14.

The cylindrical portion 15 is cylindrical with the central axis J as a center. The tubular portion 15 extends along the axial direction. The rotor core 13 b and the rotor magnet 13 a 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 13b.

The disc portion 14 is located at an opening on the inner side (the other side in the axial direction) of the cylindrical portion 15 in the vehicle width direction. Further, the disc portion 14 closes the opening on the inner side (the other side in the axial direction) of the cylindrical portion 15 in the vehicle width direction. The disk portion 14 has a disk shape centered on the central axis J. The disc portion 14 has a first surface 14a facing inward in the vehicle width direction and a second surface (bottom surface) 14b facing outward in the vehicle width direction. The second surface 14 b axially faces the planetary gear 22.

A fixing hole 14 h is provided at the center of the disc portion 14 in plan view. The outer peripheral surface of the second shaft 12B of the input shaft 12 is fitted in the fixing hole 14h. That is, the rotor holder 13 is fixed to the input shaft 12 at the disk portion 14. Further, the shaft flange portion 12 d of the input shaft 12 contacts the second surface 14 b. Thereby, the input shaft 12 is axially aligned with the disc portion 14.
The rotor holder 13 and the input shaft 12 may be indirectly fixed via other members.

On the first surface 14 a of the disk portion 14, a resolver support portion 14 c that protrudes in the axial direction is provided. That is, the disc part 14 has the resolver support part 14c. The resolver support portion 14c protrudes inward in the vehicle width direction (the other side in the axial direction). The resolver support 14 c extends along the circumferential direction. That is, the resolver support portion 14c is cylindrical with the central axis J as a center. The resolver rotor 5b is fixed to the tip of the resolver support 14c. The resolver rotor 5b radially faces the resolver stator 5a. The resolver rotor 5 b and the resolver stator 5 a constitute a resolver 5. The resolver 5 detects the rotation angle of the rotor 11 with respect to the case 40.

According to the present embodiment, the rigidity of the disc portion 14 can be enhanced by providing the disc portion 14 with the resolver support portion 14 c that protrudes in the axial direction and extends in the circumferential direction. When the disc portion 14 is deformed, the cylindrical portion 15 may be displaced, and the gap between the rotor magnet 13 a and the stator 17 may be uneven. 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 secured.

The rotor core 13 b is caulked and fixed to the cylindrical portion 15 of the rotor holder 13. The rotor core 13 b is configured by laminating laminated steel plates along the axial direction. The rotor core 13b is provided with a plurality of holding holes 13c for holding the rotor magnet 13a.

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

In the present embodiment, the rotor magnet 13a is composed of twelve segment magnets 13aa. That is, the rotor magnet 13a has twelve segment magnets 13aa. Further, in the present embodiment, the rotor magnet 13a has 12 poles. The rotor magnet 13a may be configured of 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 segment magnet 13aa corresponding to each pole decreases, and the magnetic force of each segment magnet 13aa decreases. As a result, the radial dimension of the rotor core 13b can be reduced. Thereby, weight reduction of the in-wheel motor 1 can be achieved. Moreover, the internal diameter of the cylindrical part 15 can be expanded by reducing the radial direction dimension of the rotor core 13b. The rotor holder 13 of the present embodiment accommodates the reduction gear unit 20 inside the cylindrical portion 15. Therefore, the degree of freedom of the number of teeth of each gear (the sun gear 21, the planetary gear 22 and the ring gear 23) constituting the reduction gear unit 20 is increased, and a more preferable reduction ratio can be realized. More specifically, the diameter of the planetary gear 22 can be increased, the number of teeth of the planetary gear 22 can be increased, and the reduction gear ratio by the reduction gear unit 20 can be increased.

Further, according to the present embodiment, by setting the number of poles of the rotor magnet 13a to 10 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, the radial dimension of the motor unit 2 can be reduced in size and weight 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 ring of the bearing member 4 is fixed to the input shaft 12. Further, the outer ring of the bearing member 4 is fixed to a bearing holding recess 47 provided in the case 40. The bearing member 4 supports the input shaft 12 on the inner side in the vehicle width direction (the other side in the axial direction) of the connection portion between the input shaft 12 and the rotor holder 13.

The type of bearing member 4 is not limited. For example, a slide bearing made of a sintered material may be used as the bearing member 4. In that case, the bearing is fixed to one of the input shaft 12 and the case 40. In the case where a material with high wear resistance is used as the case 40 (more specifically, the first bottom plate 42), the case 40 itself may be used as a bearing.

<Reduction gear section>
The reduction gear unit 20 is connected to the rotor 11 of the motor unit 10 to reduce the rotation 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 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 reduction gear unit 20 constitutes a planetary gear mechanism, the input shaft 12 for inputting motive power and the output shaft 29 for outputting motive power can be coaxially arranged. Thereby, the motor unit 2 can be miniaturized.

In the present embodiment, the sun gear 21, the planetary gear 22 and the ring gear 23 are helical gears (helical gears). Therefore, when the reduction gear unit 20 operates, the sun gear 21, the planetary gear 22 and the ring gear 23 receive axial stress from the gears meshing with each other. The axial stress received by the sun gear 21 and the ring gear 23 and the axial stress received by the planetary gear 22 are opposite to each other. In the present embodiment, when moving the vehicle forward, the sun gear 21 and the ring gear 23 receive a stress from the planetary gear 22 facing inward in the vehicle width direction (the other side in the axial direction), and the planetary gear 22 receives the stress from the sun gear 21 and the ring gear 23. Receives stress that is directed outward (one axial side). Also, when moving the vehicle backward, each gear is subjected to stress in the opposite direction when moving forward.

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 with the input shaft 12.

In the present embodiment, the sun gear 21 is provided by processing teeth on the outer peripheral surface of the first shaft 12A. That is, in the present embodiment, the sun gear 21 and the first shaft 12A are a single 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 another 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 meshes with the sun gear 21 and rotates. The planetary gear 22 rotates on the rotation axis Jp. The planetary gear 22 revolves around the sun gear 21. Three planetary gears 22 are provided in the reduction gear unit 20 of the present embodiment. The three planetary gears 22 are arranged at equal intervals along the circumferential direction. The number of planetary gears 22 is not limited as long as a plurality of planetary gears 22 are provided in the reduction gear unit 20.

At the center of the planetary gear 22, an axially extending gear central hole 22a is provided. The carrier pin 24 is inserted into the gear center hole 22a. The planetary gear 22 rotates around the carrier pin 24.

In general, a stepped gear may be used as a planetary gear of a planetary gear mechanism. Such a stepped gear has two gears arranged axially and coaxially. The two gears are fixed to one another. The stepped gear meshes with the sun gear in one of the two gears, and meshes with the ring gear in the other gear.
On the other hand, 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 in one gear. Accordingly, the sun gear 21, the planetary gear 22 and the ring gear 23 mutually overlap in the axial direction. With such a configuration, the axial dimension of the reduction gear unit 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 gear 22. A bearing member (third bearing member) 22 b is disposed between the outer peripheral surface of the carrier pin 24 and the inner peripheral surface of the gear center hole 22 a of the planetary gear 22.

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

The carrier pin 24 is provided with a first in-pin oil passage 85, a plurality of second in-pin oil passages 86, and a third in-pin oil passage 87.

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

The second in-pin oil passage 86 extends from the first in-pin oil passage 85 radially outward of the rotation axis Jp. The second in-pin oil passage 86 establishes communication between the first in-pin oil passage 85 and the outside of the carrier pin 24. The second in-pin oil passage 86 overlaps the planetary gear 22 in the axial direction. Therefore, the second in-pin oil passage 86 opens inside the gear center hole 22a. In the present embodiment, the carrier pin 24 is provided with four second in-pin oil passages 86. The four second in-pin oil passages 86 are equally spaced in the circumferential direction of the rotation axis Jp.

The third in-pin oil passage 87 extends radially inward from the first in-pin oil passage 85. The third in-pin oil passage 87 establishes communication between the first in-pin oil passage 85 and the outside of the carrier pin 24. The third in-pin oil passage 87 is located outside (in the axial direction) the second in-pin oil passage 86 in the vehicle width direction. The third in-pin oil passage 87 opens inside the first pin holding hole 25 a provided in the carrier 25 of the output shaft 29.

The output shaft 29 supports the carrier pin 24. The output shaft 29 rotates around the central axis J as the planetary gear 22 and the carrier pin 24 revolve. The output shaft 29 is rotatably supported by the hub bearing 60 described above.

The output shaft 29 has a cylindrical output shaft main body 29 </ b> A extending in the axial direction around the central 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 29A. In the present embodiment, the output shaft body 29A and the carrier 25 are a single member. However, the output shaft main body 29A and the carrier 25 may be separate members connected to each other.

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

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

The carrier lid 26 is fixed to the carrier 25. Carrier lid portion 26 is located on the inner side in the vehicle width direction (the other side in the axial direction) with respect to carrier 25. The carrier lid 26 includes a lid body 26 a and a fixing portion 26 b projecting from the lid body 26 a toward the carrier 25.

The lid main body portion 26 a is in the shape of a disk centered on the central axis J. The planetary gear 22 is disposed between the carrier 25 and the lid 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 lid main body 26a.

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

The fixing portion 26 b extends outward in the vehicle width direction (one side in the axial direction) from the outer peripheral edge of the lid main portion 26 a in the radial direction. The fixing portion 26 b is fixed to the carrier 25 at the tip end. That is, the carrier cover 26 is fixed to the carrier 25 at the fixing part 26 b. The fixing portion 26 b extends between the planetary gears 22 in the circumferential direction. In the present embodiment, the carrier lid 26 is provided with three fixing portions 26 b.

In the axial direction, first thrust washers 22c are interposed between the carrier 25 and the planetary gear 22 and between the lid main body 26a and the planetary gear 22, respectively. When the reduction gear unit 20 operates, the planetary gear 22 is stressed from the sun gear 21 and the ring gear 23 in any axial direction. By providing the first 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 29 a is provided on the end face of the carrier 25 facing inward in the vehicle width direction (the other side in the axial direction). That is, the carrier 25 is provided with a recess 29 a that opens in the axial direction.

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

A second thrust washer 29 c is interposed between the bottom surface of the recess 29 a and the first end 12 a 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 gear 22. Along with this, the first end 12a of the input shaft 12 is pressed against the bottom of the recess 29a. According to the present embodiment, by providing the second thrust washer 29 c, the rotation of the input shaft 12 can be made smooth and the wear of the end face of the first end 12 a of the input shaft 12 can be suppressed.

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

The carrier 25 is provided with an internal carrier oil passage 84 extending radially outward from the recess 29a. The in-carrier oil passage 84 opens in the groove 29 b on the inner peripheral surface of the recess 29 a. Further, the in-carrier oil passage 84 opens at the inner peripheral surface of the first pin holding hole 25a.

The in-carrier oil passage 84 is connected to a third in-pin oil passage 87 provided in the carrier pin 24. The in-carrier oil passage 84 is connected to the first in-pin oil passage 85 via the third in-pin oil passage 87. That is, the third in-pin oil passage 87 is in communication with the first in-pin oil passage 85 and the in-carrier 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 at the radially inner side, and meshes with the ring gear 23 at the radial outer side.

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

As shown in FIG. 1, the ring gear cylindrical portion 23 b is provided with a ring gear through hole 23 d located below the central 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. The ring gear through hole 23 d preferably overlaps the central axis J when viewed in the vertical direction.

As shown in FIG. 3, the ring gear 23 is fixed to the second bottom plate 43 of the case 40 at the ring gear flange portion 23 c. Therefore, when the sun gear 21 rotates, the planetary gear 22 rotates while revolving around the sun gear 21. The carrier 25 rotates around the central axis J as the planetary gear 22 revolves. The carrier 25 is fixed to the wheel 3 via the output shaft main body 29A. Thus, the rotation of the carrier 25 is transmitted to the wheel 3.

According to the present embodiment, since the ring gear 23 has the ring gear flange portion 23c, the rigidity is enhanced. Thereby, the thickness in the radial direction of the ring gear main body 23a can be reduced, and the weight reduction of the motor unit 2 can be achieved.

In the present embodiment, at least a part of the sun gear 21, the planetary gear 22 and the ring gear 23 is accommodated radially inward of the cylindrical portion 15 of the rotor holder 13. Therefore, the axial dimension of the motor unit 2 can be reduced. Furthermore, the in-wheel motor 1 can be thinned in the axial direction.

<Pump part>
The pump unit 30 is provided at the center of the first bottom plate 42. The pump unit 30 is disposed on the inner side in the vehicle width direction (the other side in the axial direction) of the input shaft 12.

The pump unit 30 has a pump chamber 31, a connection member 34, an external gear (inner rotor) 32, an internal gear (outer rotor) 33, an inlet 35, and an outlet 36.

The pump chamber 31 is formed in a space surrounded by the inner wall surface of the pump housing recess 46 provided on the first surface 42 a of the first bottom plate 42 and the lid 44 covering the opening of the pump housing recess 46. An O-ring 44 a is provided between the lid 44 and the first surface 42 a of the first bottom plate 42. Thus, the pump chamber 31 is sealed to the outside. The pump chamber 31 accommodates the external gear 32 and the internal gear 33. A central axis J passes through the pump chamber 31. The outer shape of the pump chamber 31 is circular when viewed from the axial direction.

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

The connecting member 34 connects the input shaft 12 and the external gear 32. One end of the connecting member 34 engages with the second shaft 12B of the input shaft 12 on the outer peripheral surface. Further, the other end of the connecting member 34 is fitted to the external gear central hole 32 a of the external gear 32 on the outer peripheral surface. The hollow portion 34 a of the connecting member 34 communicates with the hollow portion 12 c provided on the input shaft 12. The hollow portion 34 a of the connecting member 34 constitutes a part of the second oil passage 82.

The external gear 32 is fixed to the second end 12 b of the input shaft 12 via the connecting member 34. The external gear 32 rotates around the central axis J together with the input shaft 12.

FIG. 5 is a cross-sectional view of the pump portion 30 in a cross section orthogonal to the central axis J. As shown in FIG.
The external gear 32 is accommodated in the pump chamber 31. The external gear 32 has a plurality of teeth 32b on the outer peripheral surface. The tooth form of the tooth portion 32b of the external gear 32 is a trochoidal tooth form.

The internal gear 33 surrounds the radially outer side of the external gear 32. The internal gear 33 is an annular gear rotatable around the rotation axis Jt which is eccentric with respect to the central axis J. The internal gear 33 is accommodated 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 shape of the tooth portion 33b of the internal gear 33 is a trochoidal tooth shape.

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

A first in-pump oil passage 38 and a second in-pump oil passage 39 are provided on the inner wall surface of the pump chamber 31. The first in-pump oil passage 38 is an oil passage in a groove provided in the bottom surface of the pump housing recess 46 and the opposing surface of the lid portion facing the bottom surface. Similarly, the second in-pump oil passage 39 is an oil passage in a groove provided in the bottom surface of the pump housing recess 46 and the opposing surface of the lid opposite to the bottom surface. The first pump internal oil passage 38 and the second pump internal oil passage 39 extend in an arc shape along the circumferential direction. The first pump internal oil passage 38 and the second pump internal oil passage 39 are arranged side by side in the circumferential direction. The first in-pump oil passage 38 and the second in-pump oil passage 39 overlap the teeth 33 b of a portion of the internal gear 33 as viewed in the axial direction.

The first in-pump oil passage 38 is connected to the first oil passage 81.
The second pump internal oil passage 39 is connected to the hollow portion 34 a of the connecting member 34. That is, the second pump internal oil passage 39 is connected to the second oil passage 82.

The suction port 35 is provided at the boundary between the first pump inner oil passage 38 and the first 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 via the first oil passage 81.

The discharge port 36 is provided at the boundary between the second in-pump oil passage 39 and the second oil passage 82. The discharge port 36 discharges the oil O from the inside of the pump chamber 31. That is, the second oil passage 82 is connected to the discharge port 36.

When the input shaft 12 rotates, the external gear 32 fixed to the input shaft 12 rotates around the central axis J. Thereby, the internal gear 33 meshing with the external gear 32 rotates around the rotation axis Jt. Further, a portion where the gap between the external gear 32 and the internal gear 33 is wide moves around the central axis J. Furthermore, oil O sucked into the pump chamber 31 from the suction port 35 is sent to the discharge port 36 through the gap between the external gear 32 and the internal gear 33. The oil O discharged from the discharge port 36 flows into the second 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 using the rotation of the input shaft 12 to suck the oil O from the lower region of the housing 49 and circulate the oil O in the oil passage 80. For this reason, the drive of the pump unit 30 does not require an external power supply. Further, oil O is circulated in the housing portion 49 to enhance the lubricity of the gears of the reduction gear portion 20, and the motor portion 10 can be cooled by the oil O.

According to the present embodiment, the discharge port 36 of the pump unit 30 is connected to the second oil passage 82 in the input shaft 12. Since the input shaft 12 rotates around the central axis J, the oil O coming out of the second oil passage 82 splashes radially outward due to the centrifugal force of the input shaft 12. For this reason, the inside of the second oil passage 82 has a negative pressure, and as a result, the suction of the oil O by the pump unit 30 is promoted. Therefore, even when the pump unit 30 is miniaturized, the pump unit 30 can have a sufficient suction force. According to this embodiment, the pump unit 30 can be miniaturized, and the motor unit 2 can be miniaturized.

<Oil path>
Next, an oil passage 80 in which the oil O is circulated in the housing portion 49 of the case 40 will be described.
The oil passage 80 includes a first oil passage 81, a second oil passage 82, a third oil passage 83, an in-carrier oil passage 84, a first in-pin oil passage 85, and a second pin. An inner oil passage 86 and a third in-pin oil passage 87 are included.

When the in-wheel motor 1 is stopped, the oil O accumulates 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 below the lower end portion of the rotor 11. Thereby, the oil O can be suppressed from becoming a resistance of the rotation of the rotor 11. The opening of the first oil passage 81 with respect to the storage 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 unit 30 is driven along with the rotation of the input shaft 12. When the pump unit 30 is driven, the oil O accumulated in the lower region of the storage unit 49 moves from the suction port 35 into the pump chamber 31 through the first oil passage 81. The oil O in the pump chamber 31 moves from the discharge port 36 to the second oil passage 82.

Part of the oil O in the second oil passage 82 flows into the third oil passage 83 by the centrifugal force caused by the rotation of the input shaft 12. Further, part of the oil O in the second oil passage 82 reaches an end of the second oil passage 82 at the outer side (one side in the axial direction) of the vehicle width direction.

The oil O flowing into the third oil passage 83 moves radially outward in the third oil passage 83 by centrifugal force. The oil O that has reached the radially outer side of the third oil passage 83 splashes radially outward from the outer peripheral surface of the input shaft 12.

According to the present embodiment, the third oil passage 83 is provided in the input shaft 12 so that oil O is scattered from the third oil passage 83 into the housing portion 49 using the centrifugal force of the input shaft 12. It can be done. As a result, the lubricity of each portion in the housing portion 49 can be enhanced, and the motor portion 10 can be cooled with the oil O.

The axial position of the third oil passage 83 overlaps the axial position of one of the pair of coil ends 18 a and 18 b (the first coil end 18 a in the present embodiment). That is, the radially outer opening of the third oil passage 83 radially faces the first coil end 18 a. The oil O splashed radially outward from the third oil passage 83 reaches the first coil end 18a and cools the first coil end 18a.
In the present embodiment, the resolver support portion 14 c of the rotor holder 13 is located between the radially outer opening of the third oil passage 83 and the first coil end 18 a. Therefore, the oil O splashed from the third oil passage 83 reaches the first coil end 18a after traveling along the surface of the resolver support portion 14c.

Further, part of the oil O diffused from the opening of the third oil passage 83 is supplied to the bearing member 4. The oil O supplied to the bearing member 4 promotes the lubrication of the bearing member 4 and suppresses the wear of the bearing member 4.

The second oil passage 82 opens at the first end 12 a of the input shaft 12. Therefore, the oil O of the second oil passage 82 flows out of the second oil passage 82 at the first end 12 a of the input shaft 12. The first end 12 a of the input shaft 12 is accommodated in a recess 29 a provided on the output shaft 29. Therefore, the second oil passage 82 opens inside the recess 29a. The oil O flows from the second oil passage 82 into the recess 29a.

The oil O flowing into the recess 29a is supplied to the second thrust washer 29c housed in the recess 29a. Thereby, the lubricity of the second thrust washer 29c and the end face of the input shaft 12 is enhanced, and the rotation of the input shaft 12 can be made smoother.

A centrifugal force is applied to the oil O flowing into the recess 29 a as the output shaft 29 rotates around the central axis J. As a result, the oil O concentrates in the plurality of grooves 29b provided on the inner peripheral surface of the recess 29a. Furthermore, the oil O flows into the in-carrier oil passage 84 opened to 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-carrier oil passage 84 opens in the groove 29b. Thus, the oil O in the recess 29a can be smoothly introduced into the in-carrier oil passage 84.

Further, part of the oil O flowing into the recess 29 a moves in the axial direction and flows out from the opening of the recess 29 a. A portion of the oil O flowing out of the opening of the recess 29 a 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 gear 22 enhances the lubricity of the second thrust washer 29 c interposed between the carrier 25 and the planetary gear 22.

The oil O flowing into the in-carrier oil passage 84 flows radially outward by the centrifugal force of the output shaft 29, and flows into the first in-pin oil passage 85 through the third in-pin oil passage 87.

According to this embodiment, the in-carrier oil passage 84 and the third in-pin oil passage 87 extend in the radial direction. Therefore, the oil O can be smoothly introduced from the recess 29 a to the first in-pin oil passage 85 by utilizing the centrifugal force accompanying the rotation of the output shaft 29.

A part of the oil O flowing into the first in-pin oil passage 85 is guided to the outer peripheral surface of the carrier pin 24 through the second in-pin oil passage 86. A bearing member 22 b 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 can be supplied to the bearing member 22b to improve the lubricity of the bearing member 22b. The oil O guided to the outer peripheral surface of the carrier pin 24 flows along the end face of the planetary gear 22 and is supplied to the second thrust washer 29 c. According to this embodiment, the lubricity of the second thrust washer 29c can be enhanced. Furthermore, the oil O flows radially outward and is supplied to the tooth surfaces of the planetary gear 22 and the ring gear 23.

A portion of the oil O flowing into the first in-pin oil passage 85 flows out of the first in-pin oil passage 85 at the axial opening of the first in-pin oil passage 85 and splashes radially outward. . A ring gear 23 is disposed radially outside the carrier pin 24. Therefore, the oil O splashed from the first in-pin oil passage 85 reaches the tooth surface of the ring gear 23. The tooth flanks of the ring gear 23 contact the tooth flanks of the planetary gear 22. The tooth flanks of the planetary gear 22 contact the tooth flanks of the sun gear 21. Therefore, the oil O reaching the tooth surface of the ring gear 23 not only enhances the lubricity of the meshing between the ring gear 23 and the planetary gear 22, but also enhances the lubricity of the meshing of the planetary gear 22 and the sun gear 21. Thereby, the mutual transmission efficiency of the sun gear 21, the planetary gear 22 and the ring gear 23 can be enhanced. In addition, wear of the sun gear 21, the planetary gear 22 and the ring gear 23 can be suppressed.

The oil O that has reached the ring gear 23 accumulates in the lower region inside the ring gear 23 in the radial direction. As shown in FIG. 1, the ring gear 23 is provided with a ring gear through hole 23 d located below the central 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 case 40 via the ring gear through hole 23d. According to the present embodiment, by providing the ring gear through hole 23d, the circulation of the oil O in the housing portion 49 can be promoted, and the oil O can be effectively used.

The ring gear through hole 23 d preferably overlaps the central axis J when viewed in the vertical direction. The ring gear 23 extends circumferentially around the central axis J. Therefore, the lowest point of the inner peripheral surface of the ring gear 23 is located directly below the central axis J. The ring gear through hole 23 d can be positioned at the lowermost point of the inner peripheral surface of the ring gear 23 by arranging the ring gear through hole 23 d so as to overlap with the central axis J when viewed in the vertical direction. Thus, the oil O in the radial direction of the ring gear 23 can be efficiently discharged.

As shown in FIG. 3, the cylindrical portion 15 of the rotor holder 13 is located on the radially outer side of the planetary gear 22. Therefore, a part of the oil O scattered to the outside in the radial direction of the planetary gear 22 via the first in-pin oil passage 85 is captured on the inner circumferential surface of the cylindrical portion 15. The oil O captured on 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 second coil end 18 b. Therefore, the oil O splashed from the opening of the rotor holder 13 reaches the second coil end 18 b and cools the second coil end 18 b.

The oil reaching the first coil end 18a and the second coil end 18b moves downward by gravity. Thus, the oil O is recovered again to the lower region of the storage portion 49.

<Brake part>
As shown in FIG. 2, the brake unit 70 includes a disk caliper 71 and a disk rotor 72. The brake unit 70 brakes the rotation of the wheel 3.

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

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

The bracket portion 72 b has an annular plate shape centered on the central axis J. In addition, the bracket portion 72b has a conical shape that inclines inward in the vehicle width direction (the other side in the axial direction) as it goes radially outward. At a radially outer end of the bracket portion 72b, a screw hole 72f is provided to which the fixing screw 72c is fastened.

An axially extending through hole 72d is provided at a radially inner end of the bracket portion 72b. The fixing screw 69 for fixing the bracket portion 72b, the inner ring 62 of the hub bearing 60 and the wheel 3 to each other is inserted through the through hole 72d. That is, the disk rotor 72 is fixed to the inner ring 62 and the wheel 3 of the hub bearing 60 at the bracket portion 72 b. Therefore, the disk rotor 72 rotates around the central axis J together with the wheel 3.

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

The caliper main body 71 a is disposed on the vehicle front side or the vehicle rear side with respect to the central axis J. The caliper main body 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 in the caliper main body 71 a. The caliper main body 71a is provided with a slit 71c extending along the circumferential direction. The slits 71c open radially inward. The disc main body 72a of the disc rotor 72 is disposed inside the slit 71c.

The pair of brake pads 71b is fixed to the inner wall surface of the slit 71c. The pair of brake pads 71b axially oppose each other with the disc main body 72a interposed therebetween.

The brake pad 71b is pushed out by the caliper body 71a in the direction approaching the disc body 72a. Thereby, the brake pad 71b contacts the surface of the disc body 72a facing in the axial direction, and brakes the disc body 72a. That is, the pair of brake pads 71 b sandwich the disc rotor 72. In FIG. 2, the axial gap between the disc main body 72a and the brake pad 71b is enlarged and displayed for easy understanding.

In the present embodiment, the disk 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 disk rotor 72 and the motor unit 2 in the axial direction.

<Wheel>
The wheel 3 has a rim portion 3a, a disc portion 3b, and a fixing portion 3c. The wheel 3 is connected to the 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 3a. The wheel 3 transmits power to the road surface via a tire.

The rim portion 3a has a cylindrical shape centered on the central 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 3a. More specifically, the entire hub carrier 50 and the entire hub bearing 60 are disposed radially inward of the rim portion 3a. That is, the entire hub carrier 50 and the entire hub bearing 60 are located inside the wheel 3.

The end of the motor unit 2 on the outer side in the vehicle width direction (one side in the axial direction) is located on the outer side in the vehicle width direction (one side in the axial direction) than the end on the inner side in the vehicle width direction (the other side in the axial direction) Do. For this reason, at least a part of the motor unit 2 is disposed radially inward of the rim portion 3a. That is, at least a part of the motor unit 2 is located inside the wheel 3.

According to the present embodiment, at least a part of the motor unit 2, the hub carrier 50, and the hub bearing 60 is accommodated inside the wheel 3 to suppress that these parts largely protrude inward in the vehicle width direction. , Can increase the freedom of design of the vehicle.

The end in the vehicle width direction inner side (axial direction other side) of the motor unit 2 is positioned inward in the vehicle width direction (axial side other side) than the end portion in the vehicle width direction inner side (axial direction other side) of the rim portion 3a. Do. For this reason, at least a part of the motor unit 2 is disposed outside the rim portion 3a. 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, a vehicle equipped with the in-wheel motor travels. According to the present embodiment, since the motor unit 2 is exposed from the wheel 3, when the vehicle travels, a flow (wind) of air relative to the case 40 is generated outside the case 40, and the case 40 is cooled. Along with this, 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 outer side (one side in the axial direction) of the rim portion 3a in the vehicle width direction. The disk 3 b extends radially inward from an end of the rim 3 a on the outer side (one side in the axial direction) in the vehicle width direction. A fixing portion 3c is provided at the radial inner end of the disc portion 3b. That is, the disk portion 3b connects the rim portion 3a and the fixing portion 3c.

The fixing portion 3 c is located at the center of the wheel 3 in plan view. The fixing portion 3 c has an annular plate shape centering on the central axis J. The fixing portion 3 c is located on the axially opposite side of the motor unit 2 with respect to the hub carrier 50 and the disk 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 along the circumferential direction.

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

<Placement of each part>
Next, the arrangement of each characteristic part of the in-wheel motor 1 of the present embodiment will be described.
As shown in FIG. 2, the motor unit 2 is positioned inward in the vehicle width direction (the other side in the axial direction) with respect to the hub carrier 50. That is, the motor unit 2 faces the hub carrier 50 in the axial direction. Also, the motor unit 2 is fixed to the hub carrier 50 in the case 40. Further, a hub bearing 60 rotatably holding the output shaft 29 of the motor unit 2 is held by the hub carrier 50 inside the central hole 50 a of the hub carrier 50. According to the present embodiment, the motor unit 2 can be easily detached from the in-wheel motor 1 by releasing the fixing with the hub carrier 50. Therefore, the motor unit 2 can be removed from the in-wheel motor 1 even when the in-wheel motor 1 is attached to the vehicle and in contact with the ground through the tires. According to this embodiment, maintenance of the motor unit 2 is facilitated.

According to the present embodiment, as shown in FIG. 1, the through hole 41 c is provided in the case 40 and the screw hole 53 a is provided in the hub carrier 50. The case 40 is fixed to the hub carrier 50 by fastening the fixing screw 59, through which the through hole 41c is inserted, to the screw hole 53a. Therefore, the head of the fixing screw 59 is turned by a spanner or the like on the side where the motor unit 2 is disposed with respect to the hub carrier 50. That is, the head of the fixing screw 59 and the motor unit 2 are positioned in the same direction with respect to the hub carrier 50. An operator does not have to move to the opposite side of the hub carrier 50 after removing the fixing screw 59 in the mounting and removing operations of the motor unit 2. According to this embodiment, the mounting operation and the removing operation of the motor unit 2 can be simplified.

According to the present embodiment, the output shaft 29 and the inner ring 62 of the hub bearing 60 are splined. Therefore, the output shaft 29 can be easily detached from the hub bearing 60 by axially moving the output shaft 29 with respect to the hub bearing 60. By moving the entire motor unit 2 inward in the vehicle width direction after removing the fixing screw 59, the motor unit 2 can be easily detached from the in-wheel motor. Therefore, maintenance of the motor unit 2 becomes easy.

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 case 40 and the outer peripheral surface of the output shaft 29 to seal the inside of the storage portion 49. Do. The sealing of the housing portion 49 is completed only by the motor unit 2. Therefore, even if the motor unit 2 is easily removed from the in-wheel motor 1, the sealing of the housing portion 49 is maintained, and the oil O can be prevented from flowing out from the housing portion 49.

According to the present embodiment, as shown in FIG. 1 and FIG. 2, the motor unit 2 is located on the axially opposite side of the fixed portion 3 c with respect to the hub carrier 50. That is, the motor unit 2 is positioned inward in the vehicle width direction (the other side in the axial direction) with respect to the hub carrier 50, and the fixing portion 3c is positioned outward in the vehicle width direction (one side in the axial direction). For this reason, in this embodiment, when removing the motor unit 2, it is not necessary to remove the wheel 3, and the removal of the motor unit 2 becomes easy.

According to this embodiment, the motor unit 2 is located on the axially opposite side of the disk rotor 72 with respect to the hub carrier 50. That is, the motor unit 2 is positioned inward in the vehicle width direction (the other side in the axial direction) with respect to the hub carrier 50, and the disc rotor 72 is positioned outward in the vehicle width direction (one side in the axial direction). For this reason, in the present embodiment, when removing the motor unit 2, it is not necessary to remove the disk rotor 72, and the removal of the motor unit 2 becomes easy.
Similarly, when removing the disc rotor 72, it is not necessary to remove the motor unit 2, and the disc rotor can be easily removed. Therefore, maintenance of the disk rotor 72 is facilitated.

Although the embodiment of the present invention has been described above, each configuration and combination thereof in the embodiment are an example, and addition, omission, substitution and other modifications of the configuration are possible without departing from the spirit of the present invention. Is possible. Further, the present invention is not limited by the embodiments.

For example, although the case where the reduction gear of a gear mechanism was employ | adopted was illustrated as a reduction gear part of the above-mentioned embodiment, you may employ | adopt the reduction gear of a roller mechanism.

Moreover, in the above-mentioned motor unit, the case where the output shaft which outputs the motive power of a motor unit was connected to a planetary gear was illustrated. However, the output shaft may be connected to the ring gear.

For example, the motor unit according to the above-described embodiment can be widely used not only for vehicles but also for various devices provided with wheels, such as unmanned transport machines, agricultural machines, robots such as cleaning robots, and the like.

DESCRIPTION OF SYMBOLS 1 ... In-wheel motor, 2 ... Motor unit, 3 ... Wheel, 3a ... Rim part, 3c, 26b ... Fixed part, 3d, 41c, 72d, 72e ... Through hole, 4 ... Bearing member (1st bearing member), DESCRIPTION OF SYMBOLS 6 ... Seal member, 9 ... Vehicle, 10 ... Motor part, 11 ... Rotor, 12 ... Input shaft, 12a ... 1st end, 12b ... 2nd end, 13 ... Rotor holder, 13a ... Rotor magnet, 13c ... Holding hole, 14 disk portion 14b second surface (bottom surface) 15 cylindrical portion 17 stator 18

coil

18a, 18b coil end 19 stator core 20 speed reducer portion 21 ... Sun gear, 22 ... Planetary gear, 22a ... Gear central hole, 22b ... Bearing member, 22c ... First thrust washer, 23 ... Ring gear, 23d ... Ring gear through hole, 24 ... Carrier pin Reference Signs List 25 carrier 25a first pin holding hole (pin holding hole) 29 output shaft 29a concave portion 29b groove portion 29c second thrust washer 29d outer peripheral surface 30 pump portion 31 ... pump chamber, 32 ... external gear, 33 ... internal gear, 35 ... suction port, 36 ... discharge port, 40 ... case, 43 j ... second fitting surface, 48 ... insertion hole, 49 ... housing part, 50 ... Hub carrier, 50a ... central hole, 53a, 62b, 72f ... screw hole, 53j ... first fitting surface, 59, 64, 69, 72c ... fixed screw, 60 ... hub bearing, 61 ... outer ring, 62 ... inner ring , 62c: inner circumferential surface, 63: rolling element, 70: brake portion, 71: disc caliper, 71b: brake pad, 72: disc rotor, 80: oil path, 81: first oil path, 82: second Oil passage, 82 ... 2nd Oil path (oil path in the input shaft), 83 ... third oil path, 83 ... third oil path (input shaft inner diameter direction oil path), 84 ... carrier internal oil path, 85 ... first in-pin oil path , 86 ... second pin internal oil passage, 87 ... third pin internal oil passage, J ... central axis, O ... oil

Claims

An in-wheel motor mounted on a vehicle,
A motor unit having an output shaft rotating about a central axis and outputting power from the output shaft;
A hub carrier provided along a plane orthogonal to the central axis and provided with a central hole through which the output shaft is inserted and fixed to the vehicle;
A hub bearing held on the hub carrier inside the central hole and rotatably supporting the output shaft with respect to the hub carrier;
And a wheel fixed to said output shaft,
The motor unit is
A motor portion having a rotor rotating around a central axis and an annular stator located radially outward of the rotor;
A reduction gear unit that decelerates the rotation of the rotor and outputs it from the output shaft;
And a case for housing the motor unit and the reduction gear unit,
The motor unit is axially opposed to the hub carrier and fixed to the hub carrier in the case.
In-wheel motor.
The hub carrier is provided with a plurality of screw holes extending along the circumferential direction and extending along the axial direction,
The case is provided with a plurality of through holes through which a plurality of fixing screws fastened to the screw holes are inserted.
The in-wheel motor according to claim 1.
Splines are provided on the outer peripheral surface of the output shaft,
The output shaft and the inner ring of the hub bearing are splined,
The in-wheel motor of Claim 1 or 2.
The wheel is
A rim that holds the tire,
And a fixing portion fixed to the output shaft,
The fixing portion is located on the axially opposite side of the motor unit with respect to the hub carrier.
The in-wheel motor according to any one of claims 1 to 3.
Equipped with a brake unit,
The brake unit is
A disc caliper fixed to the hub carrier;
And a disk rotor fixed to the wheel.
The disc caliper has a pair of brake pads sandwiching the disc rotor,
The disk rotor is located axially opposite to the motor unit with respect to the hub carrier.
The in-wheel motor according to any one of claims 1 to 4.
The reduction gear unit
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 planetary gears and meshed with the plurality of planetary gears;
A plurality of carrier pins which are inserted into a gear center hole provided in the planetary gear and respectively support a plurality of the planetary gears;
And a carrier for holding a plurality of the carrier pins.
The in-wheel motor according to any one of claims 1 to 5.
The hub carrier has a first mating surface extending along the circumferential direction and facing radially inward,
The case has a second fitting surface that extends along the circumferential direction and faces radially outward and is fitted to the first fitting surface.
The in-wheel motor according to any one of claims 1 to 6.
The case is provided with an insertion hole through which the output shaft is inserted,
A seal member is provided between the inner peripheral surface of the insertion hole and the outer peripheral surface of the output shaft.
The in-wheel motor according to any one of claims 1 to 7.