WO2017163480A1

WO2017163480A1 - In-wheel motor drive device

Info

Publication number: WO2017163480A1
Application number: PCT/JP2016/082962
Authority: WO
Inventors: 四郎田村; 真也太向
Original assignee: Ntn株式会社
Priority date: 2016-03-22
Filing date: 2016-11-07
Publication date: 2017-09-28

Abstract

A wheel hub bearing section (11) has: an outer ring (12) adapted to be joined to a wheel (W) disposed on one side of the wheel hub bearing section in the direction of the axis (O) thereof; a stationary shaft (15) passed through the center hole of the outer ring; and a plurality of rolling bodies (14) arranged in the annular space between the outer ring and the stationary shaft. A motor section (21) and a speed reduction section (31) are disposed offset from the axis of the wheel hub bearing section in the direction normal to the axis. The motor section is disposed adjacent to the other axial end (15r) of the stationary shaft. The speed reduction section has: an output gear (40) coupled with the outer ring; and a rolling bearing (41) provided between the output gear and the stationary shaft and rotatably supporting the output gear. A carrier (18) is disposed on the other axial side of the wheel hub bearing section and is affixed to the other axial end of the stationary shaft.

Description

In-wheel motor drive device

The present invention relates to an in-wheel motor drive device that is disposed inside a wheel and drives the wheel, and more particularly to a wheel hub bearing including a rotating outer ring and a fixed inner ring.

Among the in-wheel motors that are arranged inside the wheels and drive the wheels, as a technique for arranging the motors offset from the rotation axis of the wheel hub, for example, conventionally described in Japanese Patent No. 57669797 (Patent Document 1) Things like are known. An in-wheel motor (electric hub) described in Patent Document 1 includes a hub coupled to a wheel of a wheel, a brake shaft extending along an axle and having one end coupled to the hub, and a disc shape coupled to the other end of the brake shaft. Having a braking rotor. The outer diameter of the brake rotor is approximately half of the inner diameter of the wheel. The hub is located inside the wheel. The electric traction unit (motor) that drives the hub is disposed away from any of the hub, the brake shaft, and the brake rotor.

JP 57669797 A

However, the present inventor has found that there is a further improvement in the conventional in-wheel motor. In other words, the electric traction unit (motor) described in Patent Document 1 is limited in arrangement space due to the presence of the wheel coupled to one end of the hub and the brake rotor coupled to the other end of the hub, and is reduced in size. Specifically, the electric traction unit (motor) is disposed so as to be offset further to the outer diameter side than the outer periphery of the braking rotor. The electric traction unit (motor) is disposed on the inner diameter side of the rim portion on the outer periphery of the wheel.

That is, the electric traction unit (motor) is constrained by a narrow annular space in which the difference between the brake rotor radius and the wheel radius is made smaller than the radius of the brake rotor. A small-diameter electric traction unit (motor) cannot generate sufficient driving torque.

Also, since the electric traction unit (motor) is arranged farther inward in the vehicle width direction than the brake shaft and the braking rotor, the electric traction unit (motor) may completely protrude from the wheel inward in the vehicle width direction and may interfere with the vehicle body.

In the patent document 1, the present inventor makes the offset distance from the axis of the hub to the axis of the electric traction unit (motor) and the distance from the axis of the hub to the outer surface of the electric traction unit (motor) longer than the radius of the braking rotor. I noticed that. Then, the present inventors have arrived at the present invention of an in-wheel motor drive device that can shorten the distance from the hub axis to the outer peripheral surface of the motor.

An in-wheel motor drive device according to the present invention includes a motor unit, a wheel hub bearing unit, a deceleration unit that decelerates the rotation of the motor unit and transmits the rotation to the wheel hub bearing unit, and a carrier that is connected to the vehicle body side member. Prepare. The wheel hub bearing portion is disposed in an outer ring for coupling with a wheel disposed on one axial direction of the wheel hub bearing portion, a fixed shaft that is passed through a center hole of the outer ring, and an annular space between the outer ring and the fixed shaft. A plurality of rolling elements. The motor portion and the speed reduction portion are arranged offset in the direction perpendicular to the axis of the wheel hub bearing portion. The motor unit is disposed adjacent to the other end portion in the axial direction of the fixed shaft. The carrier is disposed on the other side in the axial direction than the wheel hub bearing portion, and is fixed to the other end portion in the axial direction of the fixed shaft.

According to the present invention, with respect to the axial position of the wheel hub bearing portion, the motor portion is disposed adjacent to the other axial end of the fixed shaft so as to be close to the fixed shaft, and from the hub axis to the electric traction unit (motor) axis. Offset distance and the distance from the wheel hub bearing axis to the outer peripheral surface of the motor part, and the diameter of the motor part can be made smaller than before in the limited space of the circular inner space of the wheel. Can be bigger. In addition, according to the present invention, by providing an output shaft bearing that rotatably supports the output shaft of the speed reduction unit separately from the wheel hub bearing unit, the output shaft can be stably supported so as not to be displaced. The reliability of the part is improved. Since the fixed shaft extends along the axis of the wheel hub bearing portion, the carrier is preferably arranged so that the axis of the wheel hub bearing portion intersects the carrier. Thereby, the load applied to the fixed shaft can be reliably received by the carrier. The vehicle body side member refers to a member close to the vehicle body side as viewed from the carrier. For example, a suspension device for attaching an in-wheel motor drive device to the vehicle body corresponds to the vehicle body side member. In order to increase the rigidity, the fixed shaft is preferably solid. A small space such as an oil passage may be formed in the solid fixed shaft. The speed reducer is not particularly limited, but is preferably a parallel shaft gear reducer or a combination of a parallel shaft gear reducer and a planetary gear set.

¡The fixed shaft and carrier are non-rotating members. Therefore, as one embodiment of the present invention, the casing wall portion of the speed reduction portion is disposed on the other axial direction side than the wheel hub bearing portion, and is coupled to the other axial end portion of the fixed shaft. According to this embodiment, the speed reduction part casing can be supported by the fixed shaft or the carrier. The casing wall portion refers to a part of the speed reduction part casing that forms the outline of the speed reduction part. The motor casing that forms the outline of the motor unit may be combined with the speed reduction unit casing.

As a preferred embodiment of the present invention, the other end portion in the axial direction of the fixed shaft includes a projecting portion projecting in the outer diameter direction from the one end portion in the axial direction, and the projecting portion of the fixed shaft as viewed in the axial direction of the wheel hub bearing portion. The motor parts are arranged so as to overlap each other. According to this embodiment, the outer diameter dimension of the motor part can be made larger than before while the motor part is offset from the axis of the wheel hub bearing part. Preferably, the motor part is an inner diameter side rotor / outer diameter side stator type, and the protruding part of the fixed shaft and the stator of the motor part are arranged so as to overlap each other when viewed in the axial direction of the wheel hub bearing part. The motor part may be arranged so as not to overlap the axial direction position of the fixed shaft with respect to the axial position of the wheel hub bearing part, and the protruding part may be installed at the boundary between the motor part and the fixed shaft. In this case, the shaft body of the fixed shaft and the stator of the motor portion can be arranged so as to overlap each other when viewed in the axial direction of the wheel hub bearing portion. Or a motor part may be arrange | positioned so that the axial direction position of a motor part may overlap with the axial direction position of a fixed shaft.

The fixed shaft and the carrier are non-rotating members and are connected to the vehicle body via a suspension device. The casing wall portion is also a non-rotating member and is preferably supported and fixed to the fixed shaft. As a more preferred embodiment of the present invention, the non-rotating protrusion is fixed to one axial wall surface of the casing wall portion. According to such an embodiment, the fixed shaft can be firmly supported at the root by setting the one end and the tip in the axial direction of the fixed shaft, the other end in the axial direction of the fixed shaft as the root, and thickening the root of the fixed shaft. . The protrusion formed at the base of the fixed shaft is preferably spread in a plate shape, for example, a flange.

As a further preferred embodiment of the present invention, the carrier is fixed to the other wall surface in the axial direction of the casing wall portion. According to this embodiment, it is possible to hold the casing wall portion so as to be sandwiched between the one fixed inner ring in the axial direction and the other carrier in the axial direction. Therefore, the fixed shaft can directly support the casing of the speed reduction unit and indirectly support the casing of the motor unit. Further, the fixed shaft is securely attached and fixed to the carrier.

As a further preferred embodiment of the present invention, the wheel hub bearing portion further includes a bolt including a head portion oriented in one axial direction and a shaft portion oriented in the other axial direction, and the shaft portion of the bolt is a protruding portion of the fixed shaft. And is screwed into a female screw hole provided in the casing wall portion. According to this embodiment, in the manufacturing and assembling process of the in-wheel motor drive device, the operator can attach and fix the fixed shaft to the casing wall portion from one side in the axial direction. Therefore, the space at the mounting location of the fixed inner ring and the casing wall portion is not restricted by the presence of the motor portion. In addition, the operator can perform the mounting and fixing work regardless of the presence or absence of the motor unit located on the other side in the axial direction, and the work efficiency is improved.

The coupling between the rotating outer ring and the output shaft is not particularly limited as long as it is coaxial. As one embodiment of the present invention, the outer ring and the output shaft are connected by a spline. According to this embodiment, the outer ring and the output shaft are connected so as not to be relatively rotatable, and the outer ring and the output shaft are allowed to move relative to each other in the axial direction and / or the direction perpendicular to the axial line. Therefore, even if the outer ring is displaced by the external force applied from the wheel, the output shaft is not displaced, and the reliability of the speed reduction unit is improved. As another embodiment, the outer ring and the output shaft may be connected by serration.

The present invention described above includes a wheel hub bearing portion for a rotating outer ring and a fixed inner ring. The inner ring is not limited to an annular shape and includes a solid shaft. In addition to this, the present invention may include a wheel hub bearing portion of a rotating inner ring / fixed outer ring. That is, an in-wheel motor drive device according to a second aspect of the present invention includes a motor unit, a wheel hub bearing unit, a deceleration unit that decelerates the rotation of the motor unit and transmits the rotation to the wheel hub bearing unit, and a carrier that is coupled to the vehicle body side member. The wheel hub bearing portion includes a rotating inner ring for coupling with a wheel arranged in one axial direction, a fixed outer ring arranged coaxially on the outer diameter side of the rotating inner ring, and an annular shape of the fixed outer ring and the rotating inner ring. The carrier includes a plurality of rolling elements arranged in the space, the motor part and the speed reduction part are arranged offset in a direction perpendicular to the axis of the wheel hub bearing part, and the carrier is arranged in the other axial direction than the wheel hub bearing part. The main body and an extending portion extending in one axial direction from the carrier main body are included, and the extended portion is fixed to the fixed outer ring.

According to such an embodiment, the carrier body is disposed on the other axial direction than the fixed outer ring. Moreover, the fixing location of the carrier and the fixed outer ring can be one side in the axial direction of the wheel hub bearing portion. Further, the motor part is arranged offset from the axis of the wheel hub bearing part. As a result, with respect to the axial position of the wheel hub bearing portion, the carrier body is the other axial direction, the fixed portion of the carrier and the fixed outer ring is also the other axial direction, and the motor portion is the intermediate in the axial direction between the carrier main body and the aforementioned fixed portion. It is arranged in the area and close to the fixed shaft, and the offset distance from the axis of the wheel hub bearing to the axis of the electric traction unit (motor) and the distance from the axis of the wheel hub bearing to the outer peripheral surface of the motor can be shortened. In addition, the diameter of the motor portion can be made larger than in the conventional case in a limited space of the circular inner space of the wheel. In addition, although one extension part may be sufficient, Preferably several are provided.

As a preferred embodiment of the present invention, the wheel hub bearing portion includes a hub attachment that is coupled to the fixed outer ring and projects outward from the fixed outer ring, and the extending portion of the carrier is attached and fixed to the hub attachment. According to this embodiment, the fixed outer ring of the wheel hub bearing part is substantially expanded to the outer diameter side, and the fixed outer ring can be securely attached and fixed to the carrier.

Thus, according to the present invention, the offset distance from the wheel hub axis to the motor axis and the distance from the wheel hub axis to the motor outer peripheral surface can be made shorter than before. Therefore, in the narrow space of the wheel wheel, the distance from the wheel wheel rim to the motor outer peripheral surface can be shortened to ensure the radial dimension of the motor portion and increase the motor output.

BRIEF DESCRIPTION OF THE DRAWINGS It is typical expanded sectional drawing which cut | disconnects and expand | deploys the in-wheel motor drive device which becomes 1st Embodiment of this invention in a predetermined plane. It is a rear view which shows the inside of the in-wheel motor drive device of the embodiment with a wheel. It is a longitudinal cross-sectional view which shows the in-wheel motor drive device of the embodiment. It is a rear view which shows the inside of the in-wheel motor drive device of the embodiment. It is sectional drawing which shows the in-wheel motor drive device of the embodiment with a suspension apparatus. It is a rear view which shows the inside of the in-wheel motor drive device of the embodiment. It is a longitudinal cross-sectional view which shows the in-wheel motor drive device of a reference example. It is sectional drawing which shows the in-wheel motor drive device which becomes 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic developed cross-sectional view showing the in-wheel motor drive device according to the first embodiment of the present invention cut and developed along a predetermined plane. FIG. 2 is a rear view showing the inside of the in-wheel motor drive device of the first embodiment together with the wheels, and the motor unit 21 and the rear portion 43b of the main body casing 43 are removed from the in-wheel motor drive device 10 in FIG. The state which looked at the inside of the in-wheel motor drive device 10 from the paper surface right side of FIG. 1 is represented. The predetermined plane shown in FIG. 1 includes a plane including the axis M and the axis Nf, a plane including the axis Nf and the axis Nl, and a plane including the axis Nl and the axis O shown in FIG. It is a connected development plane.

As shown in FIG. 1, the in-wheel motor drive device 10 includes a wheel hub bearing portion 11 connected to the center of the wheel wheel W represented by a virtual line, a motor portion 21 that drives the wheel wheel W of the wheel, and a motor portion. Is provided in a wheel housing (not shown) of the electric vehicle. The motor unit 21 and the speed reduction unit 31 are not arranged coaxially with the axis O of the wheel hub bearing unit 11 but are offset from the axis O of the wheel hub bearing unit 11 as shown in FIG. The wheel wheel W is well known, and a tire T is fitted on the outer periphery of the wheel wheel W, and is disposed on the front, rear, left and right sides of the vehicle body. Such a vehicle body constitutes an electric vehicle together with the wheels. The in-wheel motor drive device 10 can drive an electric vehicle at a speed of 0 to 180 km / h on a public road.

The wheel hub bearing portion 11 is disposed in an annular gap between the outer ring 12 as a wheel hub coupled with the wheel wheel W, the inner fixing member 13 passed through the center hole of the outer ring 12, and the outer ring 12 and the inner fixing member 13. A plurality of rolling elements 14 are included to constitute an axle. The inner fixing member 13 includes a non-rotating fixing shaft 15, a pair of inner races 16, and a retaining nut 17. The fixed shaft 15 has a root portion 15r having a larger diameter than the tip portion 15e. The inner race 16 is fitted to the outer periphery of the fixed shaft 15 between the root portion 15r and the tip portion 15e. The retaining nut 17 is screwed into the tip portion 15e of the fixed shaft 15, and the inner race 16 is fixed between the retaining nut 17 and the root portion 15r.

The fixed shaft 15 extends along the axis O, and the tip portion 15e of the fixed shaft 15 is directed outward in the vehicle width direction. The root portion 15r of the fixed shaft 15 protrudes inward in the vehicle width O direction from the outer ring 12 and faces an opening 43q formed in the back surface portion 43b of the main body casing 43. A carrier (not shown) is inserted into the opening 43q from the outside, and the carrier is attached and fixed to the root portion 15r inside the main body casing 43. Further, the carrier is coupled to a suspension member (not shown) outside the main body casing 43.

The rolling elements 14 are arranged in double rows with a separation in the direction of the axis O. The outer peripheral surface of one inner race 16 in the axis O direction constitutes the inner raceway surface of the rolling elements 14 in the first row, and faces one inner peripheral surface of the outer ring 12 in the axis O direction. The outer peripheral surface of the other inner race 16 in the direction of the axis O constitutes the inner raceway surface of the rolling elements 14 in the second row, and faces the other inner peripheral surface of the outer ring 12 in the direction of the axis O. In the following description, the vehicle width direction outer side (outboard side) is also referred to as one axial direction, and the vehicle width direction inner side (inboard side) is also referred to as the other axial direction. The left-right direction in FIG. 1 corresponds to the vehicle width direction. The inner peripheral surface of the outer ring 12 constitutes the outer raceway surface of the rolling element 14.

A flange portion 12f is formed at one end of the outer ring 12 in the axis O direction. The flange portion 12f constitutes a coupling seat portion for coupling coaxially with a brake rotor and a spoke portion Ws of the wheel W which are not shown. The outer ring 12 is coupled to the wheel wheel W at the flange portion 12f and rotates integrally with the wheel wheel W.

As shown in FIG. 1, the motor unit 21 has a motor rotating shaft 22, a rotor 23, a stator 24, a motor casing 25, and a motor casing cover 25v, and sequentially from the axis M of the motor unit 21 to the outer diameter side in this order. Be placed. The motor unit 21 is a radial gap motor of an inner rotor and outer stator type, but may be of other types. For example, although not shown, the motor unit 21 may be an axial gap motor.

The axis M that is the rotation center of the motor rotation shaft 22 and the rotor 23 extends in parallel with the axis O of the wheel hub bearing portion 11. That is, the motor unit 21 is disposed offset from the axis O of the wheel hub bearing unit 11. Most of the axial direction positions of the motor unit 21 excluding the front end of the motor rotating shaft 22 do not overlap with the axial direction O position of the inner fixing member 13 as shown in FIG. The motor casing 25 has a substantially cylindrical shape. The motor casing 25 is coupled to the back surface portion 43b of the main body casing 43 at one end in the axis M direction, and is sealed with a bowl-shaped motor casing cover 25v at the other end in the axis M direction. Both end portions of the motor rotating shaft 22 are rotatably supported by the motor casing 25 via rolling

bearings

27 and 28. The motor unit 21 drives the outer ring 12.

The speed reduction unit 31 includes an input shaft 32, an input gear 33, an intermediate gear 34, an intermediate shaft 35, an intermediate gear 36, an intermediate gear 37, an intermediate shaft 38, an intermediate gear 39, an output gear 40, an output shaft 41, and a main body casing 43. Have. The input shaft 32 is a cylindrical body having a larger diameter than the distal end portion 22 e of the motor rotation shaft 22, and extends along the axis M of the motor portion 21. The distal end portion 22 e is received in the center hole at the other end portion in the axis M direction of the input shaft 32, and the input shaft 32 is coupled coaxially with the motor rotation shaft 22. Both ends of the input shaft 32 are supported by the main body casing 43 via rolling

bearings

42a and 42b. The input gear 33 is an external gear having a smaller diameter than the motor unit 21 and is coupled to the input shaft 32 coaxially. Specifically, the input gear 33 is integrally formed on the outer periphery of the central portion of the input shaft 32 in the axis M direction.

The output shaft 41 is a cylindrical body having a diameter larger than that of the outer ring 12 and extends along the axis O of the wheel hub bearing portion 11. The other end of the outer ring 12 in the direction of the axis O is received in the center hole of one end of the output shaft 41 in the direction of the axis O, and the output shaft 41 is coupled to the outer ring 12 coaxially. Specifically, a spline groove 41s is formed on the inner peripheral surface of the output shaft 41, a spline groove 12s is formed on the outer peripheral surface of the other end of the outer ring 12 in the axis O direction, and the

spline grooves

41s and 12s are spline-fitted. . Such spline fitting realizes torque transmission between the output shaft 41 and the outer ring 12 and allows relative movement between the two.

The one end of the output shaft 41 in the direction of the axis O is supported by the main body casing 43 via a rolling bearing 44. The other end of the output shaft 41 in the direction of the axis O is supported by a root portion 15r of the fixed shaft 15 via a rolling bearing 46. The output gear 40 is an external gear and is coupled to the output shaft 41 coaxially. Specifically, the output gear 40 is integrally formed on the outer periphery of the other end of the output shaft 41 in the axis O direction.

The two

intermediate shafts

35 and 38 extend in parallel with the input shaft 32 and the output shaft 41. That is, the speed reduction unit 31 is a four-axis parallel shaft gear reducer, and the axis O of the output shaft 41, the axis Nf of the intermediate shaft 35, the axis Nl of the intermediate shaft 38, and the axis M of the input shaft 32 are parallel to each other. In other words, it extends in the vehicle width direction. The parallel shaft gear reducer refers to a reducer in which an input shaft and an output shaft extend in parallel, and may include one or a plurality of intermediate shafts extending in parallel.

The vehicle longitudinal direction position of each axis will be described. As shown in FIG. 2, the axis M of the input shaft 32 is arranged in front of the vehicle with respect to the axis O of the output shaft 41. The axis Nf of the intermediate shaft 35 is disposed in front of the vehicle with respect to the axis M of the input shaft 32. The axis Nl of the intermediate shaft 38 is arranged in front of the vehicle with respect to the axis O of the output shaft 41 and behind the axis M of the input shaft 32. As a modification (not shown), the input shaft 32, the intermediate shaft 35, the intermediate shaft 38, and the output shaft 41 may be arranged in this order in the vehicle front-rear direction. This order is also the order in which the driving force is transmitted.

Describing the vertical position of each axis, the axis M of the input shaft 32 is arranged above the axis O of the output shaft 41. The axis Nf of the intermediate shaft 35 is disposed above the axis M of the input shaft 32. The axis Nl of the intermediate shaft 38 is disposed above the axis Nf of the intermediate shaft 35. The plurality of

intermediate shafts

35 and 38 need only be disposed above the input shaft 32 and the output shaft 41, and the intermediate shaft 35 may be disposed above the intermediate shaft 38 as a modification (not shown). Alternatively, as a modification not shown, the output shaft 41 may be disposed above the input shaft 32.

The intermediate gear 34 and the intermediate gear 36 are external gears, and are coupled coaxially with the central portion of the intermediate shaft 35 in the axis Nf direction as shown in FIG. Both ends of the intermediate shaft 35 are supported by the main body casing 43 via rolling

bearings

45a and 45b. The intermediate gear 37 and the intermediate gear 39 are external gears, and are coupled coaxially with the central portion of the intermediate shaft 38 in the direction of the axis Nl. Both ends of the intermediate shaft 38 are supported by the main body casing 43 via rolling

bearings

48a and 48b.

The main body casing 43 forms an outer shell of the speed reduction part 31 and the wheel hub bearing part 11, is formed in a cylindrical shape, and surrounds axes O, Nf, Nl and M extending in parallel to each other as shown in FIG. The main body casing 43 is accommodated in the inner space of the wheel wheel W. The inner space of the wheel W is defined by the inner peripheral surface of the rim portion Wr and the spoke portion Ws that is coupled to one end of the rim portion Wr in the axis O direction. One area in the axial direction of the wheel hub bearing portion 11, the speed reduction portion 31, and the motor portion 21 is accommodated in the inner space region of the wheel wheel W. Further, the other axial region of the motor unit 21 protrudes from the wheel W to the other axial direction. Thus, the wheel wheel W accommodates most of the in-wheel motor drive device 10.

Referring to FIG. 2, the main body casing 43 protrudes downward at a position away from the axis O of the output gear 40 in the longitudinal direction of the vehicle, specifically, directly below the axis M of the input gear 33. This protruding portion forms an oil tank 47. On the other hand, a space S is secured between a portion 43c of the main body casing 43 directly below the axis O and a lower portion of the rim portion Wr. A suspension member 71 extending in the vehicle width direction is disposed in the space S, and the vehicle width direction outer end 72 of the suspension member 71 and the inner fixing member 13 are connected to each other via the ball joint 60 so as to be freely directional.

The main body casing 43 has a cylindrical shape, and as shown in FIG. 1, the input shaft 32, the input gear 33, the intermediate gear 34, the intermediate shaft 35, the intermediate gear 36, the intermediate gear 37, the intermediate shaft 38, the intermediate gear 39, and the output gear. 40 and the output shaft 41 are accommodated, and the other end of the wheel hub bearing portion 11 in the axis O direction is covered. Lubricating oil is enclosed in the main body casing 43. The input gear 33, the intermediate gear 34, the intermediate gear 36, the intermediate gear 37, the intermediate gear 39, and the output gear 40 are helical gears.

As shown in FIG. 1, the main body casing 43 has a substantially flat front portion 43 f that covers one side in the axial direction of the cylindrical portion of the speed reduction portion 31 and a substantially flat surface that covers the other side in the axial direction of the cylindrical portion of the speed reduction portion 31. It includes a back portion 43b. The back surface portion 43 b is coupled to the motor casing 25. The back surface portion 43b is coupled to a suspension member (not shown) such as an arm or a strut via a carrier (not shown). Thereby, the in-wheel motor drive device 10 is supported by the suspension member.

An opening 43p through which the outer ring 12 passes is formed in the front portion 43f. The opening 43p is provided with a sealing material 43s for sealing an annular gap with the outer ring 12. For this reason, the outer ring 12 serving as a rotating body is accommodated in the main body casing 43 except for one end portion in the axis O direction. The front portion 43 f is a single member and supports the rolling bearing 42 a and the rolling bearing 44.

The small-diameter input gear 33 and the large-diameter intermediate gear 34 are arranged on one side in the axial direction of the speed reduction unit 31 and mesh with each other. The small-diameter intermediate gear 36 and the large-diameter intermediate gear 37 are arranged on the other side in the axial direction of the speed reduction portion 31 and mesh with each other. The small-diameter intermediate gear 39 and the large-diameter output gear 40 are disposed on one side in the axial direction of the speed reduction unit 31 and mesh with each other. Thus, the input gear 33, the plurality of

intermediate gears

34, 36, 37, 39 and the output gear 40 mesh with each other, and the input gear 33 passes through the plurality of

intermediate gears

34, 36, 37, 39 to the output gear 40. To reach the drive transmission path. The rotation of the input shaft 32 is decelerated by the intermediate shaft 35, the rotation of the intermediate shaft 35 is decelerated by the intermediate shaft 38, and the rotation of the intermediate shaft 38 is decelerated by the output shaft 41. Is done. Thereby, the deceleration part 31 ensures a sufficient reduction ratio. Among the plurality of intermediate gears, the intermediate gear 34 is a first intermediate gear positioned on the input side of the drive transmission path. Among the plurality of intermediate gears, the intermediate gear 39 is a final intermediate gear located on the output side of the drive transmission path.

As shown in FIG. 1, the input gear 33, the intermediate gear 34, the intermediate gear 39, and the output gear 40 are arranged on one side in the axial direction (outside in the vehicle width direction) of the speed reduction unit 31 to form a first row gear group. To do. The intermediate gear 36 and the intermediate gear 37 are arranged on the other side in the axial direction of the speed reduction unit 31 (inner side in the vehicle width direction) to constitute a first row gear group. The position in the axis O direction of the gear group in the first row overlaps with the position in the axis O direction of the outer ring 12, overlaps with the position in the axial direction of the rolling bearing 46, and overlaps with the position in the axial direction of the rolling elements 14 in the second row. On the other hand, the gear group in the second row is arranged away from the outer ring 12 in the other direction in the axis O direction, and the positions in the axis O direction of both do not overlap.

As shown in FIG. 2, the output shaft 41, the intermediate shaft 38, and the input shaft 32 are arranged at intervals in the vehicle front-rear direction in this order. Further, the intermediate shaft 35 and the intermediate shaft 38 are disposed above the input shaft 32 and the output shaft 41. According to the first embodiment, the intermediate shaft can be disposed above the outer ring 12 that serves as a wheel hub, and a space for the oil tank 47 can be secured below the outer ring 12, or the space S can be formed directly below the outer ring 12. Can be secured. Accordingly, the turning shaft extending in the vertical direction can be provided so as to intersect the space S, and the wheel wheel W and the in-wheel motor drive device 10 can be suitably turned around the turning shaft.

Further, according to the present embodiment, as shown in FIG. 2, the axis M of the motor portion 21 is arranged offset from the axis O of the wheel hub bearing portion in the vehicle front-rear direction, and the axis Nf of the intermediate shaft 35 is the wheel hub bearing. The axis Nl of the intermediate shaft 38 is offset upward from the axis O of the wheel hub bearing part. Thereby, the space S can be ensured between the portion 43c directly below the axis O in the in-wheel motor drive device 10 and the lower portion of the rim portion Wr. And the steering axis of a wheel can be arranged so that it may intersect with wheel wheel W, and the turning characteristic of a wheel improves.

Further, according to the present embodiment, as shown in FIG. 1, the input shaft 32 and the output shaft 41 extend in the vehicle width direction, and as shown in FIG. 2, the input gear 33 and the output gear 40 are set to stand up and down. The lower edge 40b of the output gear 40 is disposed below the lower edge 33b of the input gear 33. As a result, the input gear 33 that rotates at a high speed is not immersed in the lubricating oil stored in the lower portion of the speed reduction unit 31 inside the main body casing 43, and the stirring resistance of the input gear 33 can be avoided.

Further, according to the present embodiment, as shown in FIG. 2, the plurality of

intermediate shafts

35, 38 are arranged adjacent to each other above the input shaft 32 and are supplied with driving torque from the input shaft 32. , And a final intermediate shaft 38 that is disposed adjacent to the output shaft 41 and supplies driving torque to the output shaft 41, and includes the input shaft 32, the first intermediate shaft 35, the final intermediate shaft 38, and the output shaft 41. Are the center of the input shaft (axis line M), the center of the first intermediate shaft 35 (axis line Nf), the center of the final intermediate shaft 38 (axis line Nl) and the output shaft in the axial direction of the plurality of

intermediate shafts

35, 38. The reference lines sequentially connecting the centers of 41 (axis O) are arranged so as to draw an inverted U-shape. As a result, the overall arrangement of the plurality of shafts and gears constituting the drive transmission path is reduced in size, and the plurality of shafts and gears can be accommodated in the wheel wheel W.

Further, according to the present embodiment, as shown in FIG. 1, the outer ring 12 that becomes a wheel hub is a cylindrical body, and the wheel hub bearing portion 11 is disposed in the center hole of the outer ring 12 to rotatably support the outer ring 12. The fixed shaft 15 is further included. Thereby, the output gear 40 can be coaxially coupled to the outer diameter side of the outer ring 12. Then, the driving force can be transmitted to the outer ring 12 from the intermediate shaft 38 arranged to be offset with respect to the outer ring 12.

The main body casing 43 further accommodates a pump shaft 51, rolling

bearings

52a and 52b, a pump gear 53, and an oil pump 54 as shown in FIG. The axis P of the pump shaft 51 extends in parallel with the axis O of the output shaft 41. The pump shaft 51 is disposed away from the output shaft 41 in the vehicle front-rear direction, is supported rotatably at both ends in the axis P direction via rolling

bearings

52a and 52b, and is coaxial with the pump gear 53 at the center in the axis P direction. Join. The pump gear 53 meshes with the output gear 40.

The oil pump 54 is disposed further on the other side in the axis P direction than the rolling bearing 52 b and is provided on the other end in the axis P direction of the pump shaft 51. When the oil pump 54 is driven by the output gear 40, the oil pump 54 sucks lubricating oil from the oil tank 47 and discharges the sucked lubricating oil to the motor unit 21 and the speed reducing unit 31. Thereby, the motor part 21 and the deceleration part 31 are lubricated.

2, the pump shaft 51 of the present embodiment is disposed below the input shaft 32, and the oil tank 47 is disposed below the pump shaft 51. The oil pump 54 is arranged substantially coaxially with the pump shaft 51 and pumps the lubricating oil stored in the oil tank 47 directly above the oil tank 47. The pump shaft 51 and the oil tank 47 are disposed in front of the output shaft 41 in the vehicle. When the wheel is driven by the in-wheel motor drive device 10 and the vehicle travels, the oil tank 47 receives traveling wind from the front of the vehicle and is cooled by air.

Next, the connection structure of the main body casing 43 and the inner fixing member 13 will be described.

FIG. 3 is a longitudinal sectional view showing the in-wheel motor drive device 10, and represents a cut surface cut along a plane including the axis O and the axis M in FIG. 2. 4 and 6 are rear views showing the inside of the in-wheel motor drive device of the embodiment, and the motor unit 21 and the back portion 43b of the main body casing 43 are removed from the in-wheel motor drive device 10 in FIG. The state which looked at the inside of the in-wheel motor drive device 10 from the paper surface right side (vehicle width direction inner side) of FIG. 1 is represented. As shown in FIG. 3, a back surface portion 43 b of the main body casing 43 is interposed between the motor portion 21 and the speed reduction portion 31 and between the motor portion 21 and the wheel hub bearing portion 11. The back surface portion 43b covers the other end of the speed reduction portion 31 and the wheel hub bearing portion 11 in the axis O direction. In FIG. 2 and subsequent figures, individual teeth on the outer periphery of the intermediate gear 34 are omitted.

The other end surface 15n of the axis O direction located on the other side of the fixed shaft 15 in the axis O direction is fixed to the one wall surface 43bm of the back surface portion 43b in the axis O direction. Specifically, a protruding portion 15p that protrudes in the outer diameter direction is provided at the root portion 15r that is the other end of the fixed shaft 15 in the axis O direction. The protruding portion 15p is fixed to the one wall surface 43bm in the axis O direction of the back surface portion 43b. The one wall surface 43 bm in the axis O direction refers to a wall surface that faces the outside in the vehicle width direction among the back surface portion 43 b that becomes the wall portion of the main body casing 43, and is an inner wall surface of the main body casing 43.

The protruding portion 15p is fixed to the back surface portion 43b by a bolt 13c. A coupling seat 43z is formed on the back surface portion 43b. The coupling seat portion 43z has a bolt hole 43zt directed in one axial direction. The bolt 13c extends parallel to the axis O, has a head portion 13cd on one side in the axis O direction, has a shaft portion 13ct on the other side in the axis O direction, and the shaft portion 13ct penetrates the protruding portion 15p to the coupling seat portion 43z. Screw together.

Suppose here that most of the wheel hub bearing portion 11 excluding the root portion 15r is disposed on the one side in the axis O direction with respect to the rear portion 43b. Most of the motor part 21 excluding the front end part 22e is arranged on the other side in the axis O direction with respect to the rear part 43b. That is, the back surface portion 43 b forms a boundary between the wheel hub bearing portion 11 and the motor portion 21. The motor casing 25 of the motor unit 21 is disposed adjacent to the root portion 15 r of the fixed shaft 15.

In FIG. 4, the motor unit 21 located on the front side in the direction perpendicular to the paper surface is indicated by a two-dot chain line. As shown in FIG. 4, the fixed shaft 15 and the motor unit 21 are disposed so as to overlap each other when viewed in the direction of the axis O of the wheel hub bearing unit 11. The protruding portion 15p extends in a plate shape from one outer peripheral surface of the fixed shaft 15 in the axis O direction, and the protruding portion 15p is also arranged so as to overlap the motor portion 21. Preferably, the protruding portion 15p of the fixed shaft 15 and the cylindrical stator 24 (FIG. 3) are arranged so as to overlap each other when viewed in the direction of the axis O. More preferably, when viewed in the direction of the axis O, the fixed shaft 15 shaft body including the distal end portion 15e (FIG. 3) and the stator 24 (FIG. 3) are arranged to overlap each other.

Next, a connection structure between the in-wheel motor drive device 10 and the suspension member 71 will be described.

FIG. 5 is a cross-sectional view showing a connection structure between the in-wheel motor drive device 10 and the suspension device 70, and shows a state seen in the vehicle front-rear direction. The spoke portion Ws of the wheel wheel W and the brake rotor BD are attached and fixed to the flange portion 12 f of the outer ring 12. A caliper (not shown) is attached and fixed to the vehicle rear portion of the main body casing 43. The caliper brakes the brake rotor BD. In order to facilitate understanding of the present invention, the brake rotor BD arranged in the inner space of the wheel W is omitted from FIG. The outer ring 12 is disposed on the outer side in the vehicle width direction when viewed from the wheel center of the wheel wheel W (the center from one end to the other end of the wheel wheel W on the axis O).

The suspension device 70 is a strut suspension device and includes two

suspension members

71 and 76. The suspension member 76 is a strut extending in the vertical direction, and includes a shock absorber 76s and can be expanded and contracted in the vertical direction. A coil spring (not shown) is coaxially disposed on the outer periphery of the upper end region 77 of the suspension member 76 to relieve the vertical axial force acting on the suspension member 76. The damper incorporated in the shock absorber 76s attenuates the expansion and contraction motion of the suspension member 76 (strut). The upper end of the suspension member 76 supports a vehicle body side member (not shown).

The suspension member 71 is a lower arm (suspension arm) that is disposed below the suspension member 76 and extends in the vehicle width direction. The end portions of the suspension member 71 constitute a vehicle width direction outer end 72 and a vehicle width direction inner end 73. The suspension member 71 is connected to the in-wheel motor drive device 10 via the ball joint 60 at the outer end 72 in the vehicle width direction. The suspension member 71 is connected to a vehicle body side member (not shown) at an inner end 73 in the vehicle width direction. The suspension member 71 can swing in the vertical direction with the vehicle width direction inner end 73 as a base end and the vehicle width direction outer end 72 as a free end. The vehicle body side member refers to a member that is attached to the vehicle body side as viewed from a member to be described.

The ball joint 60 includes a ball stud 61 and a socket 62. The ball stud 61 extends in the vertical direction, and has a ball portion 61b formed at the upper end and a stud portion 61s formed at the lower end. The socket 62 is provided on the inner fixing member 13 side and slidably accommodates the ball portion 61b. The stud portion 61s penetrates the vehicle width direction outer end 72 in the vertical direction. A male screw is formed on the outer periphery of the lower end of the stud portion 61s, and the stud portion 61s is attached and fixed to the suspension member 71 by screwing a nut 72n from below.

As shown in FIG. 5, the carrier 18 is coupled to the back surface portion 43b by a bolt 13b. The fixed shaft 15 is arranged inside the main body casing 43 and the carrier 18 is arranged outside the main body casing 43 with the back surface portion 43b which is a wall portion of the main body casing 43 as a boundary. The bolt 13b extends in parallel with the axis O, has a head portion on the inner side in the vehicle width direction, is inserted into the through hole of the carrier 18 from the inner side in the vehicle width direction, and is a through hole in the rear portion 43b on the outer side in the vehicle width direction than the carrier 18 Is further screwed into the female screw hole of the root portion 15r of the fixed shaft 15 on the outer side in the vehicle width direction than the back surface portion 43b.

As shown in FIG. 5, the carrier 18 has an upper arm portion 18a extending upward and a lower arm portion 18b extending downward. The upper arm portion 18a protrudes upward beyond the wheel hub bearing portion 11, and is attached and fixed to the lower end portion 76b of the suspension member 76 (strut) by a bolt 78 at the tip portion. The lower arm portion 18b protrudes downward beyond the wheel hub bearing portion 11, and has a socket 62 of the ball joint 60 at the tip portion. The lower arm portion 18b changes its direction at the tip portion and extends in parallel with the axis O, and wraps directly under the wheel hub bearing portion 11. For this reason, the position of the socket 62 in the direction of the axis O overlaps the position of the fixed shaft 15 in the direction of the axis O. As shown in FIG. 6, the edge of the carrier 18 is formed in an arc 18 t corresponding to the outer peripheral surface of the motor unit 21. The concave arc 18t receives the motor casing 25. For this reason, the motor unit 21 does not interfere with the carrier 18.

The ball portion 61b is allowed to rotate in a free direction as a connection point between the in-wheel motor drive device 10 and the suspension device 70. The straight line extending in the vertical direction through the upper end of the suspension member 76 (strut) and the ball portion 61b constitutes the wheel wheel W and the steered shaft K of the in-wheel motor drive device 10.

By the way, according to the in-wheel motor drive device 10 of the present embodiment, the back surface portion 43b which becomes the casing wall portion of the main body casing 43 covers the other end of the wheel hub bearing portion 11 in the axis O direction. The rear portion 43 b covers one end of the motor portion 21 in the axis O direction and is interposed between the motor portion 21 and the wheel hub bearing portion 11. Then, the other end face 15n in the axis O direction of the fixed shaft 15 is fixed to the one wall face 43bm in the axis O direction of the back surface portion 43b. The carrier 18 is disposed on the other side in the axis O direction with respect to the wheel hub bearing portion 11 and is fixed to the back surface portion 43b. Thus, the wheel hub bearing portion 11 is disposed on one side in the axis O direction and the motor portion 21 is disposed on the other side in the axis O direction with the back surface portion 43b of the main body casing 43 as a boundary. Therefore, as shown in FIG. 4, the offset distance Ds from the axis O of the wheel hub bearing 11 to the axis M of the motor 21 and the distance from the axis O of the wheel hub bearing 11 to the outer peripheral surface of the motor 21 are shortened. The diameter dimension of the motor part 21 can be made larger than before. Moreover, the dimension Dm which the motor part 21 protrudes from the main body casing 43 can be made small, and interference with the wheel wheel W and the motor part 21 can be avoided. According to the present embodiment, the wheel wheel W can be reduced in diameter, and the unsprung weight of the suspension device 70 can be reduced.

Moreover, according to this embodiment, since it has the rolling bearing 46 which supports the output shaft 41 of the deceleration part 31 rotatably besides the wheel hub bearing part 11, it supports stably so that the output shaft 41 may not displace. As a result, the durability and reliability of the deceleration unit 31 are improved.

In order to facilitate understanding of the present embodiment, a reference example will be described. FIG. 7 is a longitudinal sectional view showing an in-wheel motor drive device 20 of a reference example. About a reference example, about the structure which is common in embodiment mentioned above, the same code | symbol is attached | subjected and description is abbreviate | omitted and a different structure is demonstrated below. In the reference example, although the root portion 15r of the fixed shaft 15 is coupled to the back surface portion 43b, the fixed shaft 15 is passed through the opening 43q of the back surface portion 43b from the other side in the axis O direction and protrudes to one side in the axis O direction. The root portion 15r is located on the other side in the axis O direction with respect to the back surface portion 43b, and is fixed to the other wall surface 43bn in the axis O direction of the back surface portion 43b. A carrier 18 is fixed to the other end face 15n of the root portion 15r in the direction of the axis O by a bolt 13b. Similarly to the bolt 13b shown in FIG. 5, the bolt 13b shown in FIG. 7 has a head portion formed on the inner side in the vehicle width direction and a shaft portion formed on the outer side in the vehicle width direction. Is screwed into a female screw formed in 15n. In FIG. 7, the individual teeth on the outer periphery of the intermediate gear 34 are omitted.

According to the reference example shown in FIG. 7, the wheel hub bearing portion 11 is disposed on one side in the axis O direction and the motor portion 21 is disposed on the other side in the axis O direction with the back surface portion 43 b of the main body casing 43 as a boundary. The root portion 15r of the fixed shaft 15 and the motor portion 21 of the wheel hub bearing portion 11 are arranged on the same side in the direction of the axis O when viewed from the back surface portion 43b. For this reason, the motor part 21 must be arranged away from the root part 15r so that the root part 15r and the motor part 21 do not overlap when viewed in the direction of the axis O, and the offset distance from the axis O to the motor part 21 is increased. The diameter of the motor unit 21 cannot be increased.

Returning to the description of the present embodiment, as shown in FIG. 4, the fixed shaft 15 and the motor portion 21 are arranged so as to overlap each other when viewed in the direction of the axis O of the wheel hub bearing portion 11. The distance from the axis O to the outer peripheral surface of the motor part 21 can be further shortened, and the diameter of the motor part 21 can be increased regardless of the presence of the wheel hub bearing part 11.

Further, according to the present embodiment, as shown in FIG. 3, the other end of the fixed shaft 15 in the axis O direction is provided with the protruding portion 15 p that protrudes in the outer diameter direction, and the protruding portion 15 p is in the direction of the axis O of the back surface portion 43 b. On the other hand, it is fixed to the wall surface 43bm. As a result, one end of the fixed shaft 15 in the direction of the axis O and the tip portion 15e, the other end of the fixed shaft 15 in the direction of the axis O as the root portion 15r, the base portion 15r is thickened, and the fixed shaft 15 is firmly supported at the root. be able to.

Further, the protruding portion 15p of the present embodiment has a head portion 13cd on one side in the axis O direction and a shaft portion 13ct on the other side in the axis O direction. The shaft portion 13ct penetrates the protruding portion 15p and is screwed to the back surface portion 43b. It is fixed to the back surface portion 43b by a bolt 13c to be joined. Thereby, in the manufacturing and assembling process of the in-wheel motor drive device 10, the operator can attach and fix the fixed shaft 15 to the back surface portion 43b from one side in the axis O direction. Therefore, the space at the mounting location of the fixed shaft 15 and the back surface portion 43 b is not restricted by the presence of the motor unit 21. In addition, the operator can perform the mounting and fixing work regardless of the presence or absence of the motor unit 21 located on the other side in the axis O direction, and the work efficiency is improved.

Further, according to the present embodiment, the outer ring 12 and the output shaft 41 are coupled by a spline, so that the outer ring 12 and the output shaft 41 are connected so as not to be relatively rotatable, and the outer ring 12 and the output shaft 41 are in the direction of the axis O. Relative movement in the direction perpendicular to the axis O is allowed slightly. Therefore, even if the outer ring 12 is displaced by an external force applied from the wheel W, the output shaft 41 is not displaced, and the reliability of the speed reduction unit 31 is improved.

Next, a second embodiment of the present invention will be described. FIG. 8 is a longitudinal sectional view showing a second embodiment of the present invention. About 2nd Embodiment, about the structure which is common in embodiment mentioned above, the same code | symbol is attached | subjected and description is abbreviate | omitted, and a different structure is demonstrated below. In the second embodiment, the wheel hub bearing portion 11 is configured to rotate the inner ring and fix the outer ring. This is different from the inner ring fixed / outer ring rotating type wheel hub bearing 11 described above.

The wheel hub bearing portion 11 of the second embodiment includes a rotating inner ring 82, a fixed outer ring 83, a double row rolling element 14 disposed in these annular spaces, and a hub attachment 85. The in-wheel motor drive device 30 of the second embodiment has the same configuration as the motor unit 21 and the speed reduction unit 31 shown in FIG. 1, but these are offset from the axis O and appear in FIG. 8. Absent. The output shaft 41 of the speed reduction portion 31 is a shaft body, and one region in the direction of the axis O of the output shaft 41 is inserted into the center hole of the rotating inner ring 82, and both are spline-fitted.

A flange 83 f is formed at one end in the axial direction of the fixed outer ring 83. A hub attachment 85 is attached and fixed to the flange 83f with bolts 84. The hub attachment 85 is formed with a through hole through which the bolt 84 is passed. The bolt 84 extends parallel to the axis O, the head is directed to the other side (inboard side) in the axis O direction, the shaft part is directed to one side (outboard side) in the axis O direction, and passes through the hub attachment 85, The tip end region of the portion is screwed into a female screw hole provided in the flange 83f.

The hub attachment 85 is a plate material having a center hole for receiving the fixed outer ring 83, and has an action of expanding the fixed outer ring 83 to the outer diameter side. The bolt 84 described above passes through the inner edge side of the hub attachment 85. A through hole through which the bolt 86 is passed is formed on the outer edge side of the hub attachment 85. The hub attachment 85 is attached and fixed to the carrier 18 described later with bolts 86.

The outer peripheral surface of the fixed outer ring 83 is supported by the inner peripheral surface of the annular wall 43g of the main body casing 43. The annular wall 43g is erected on the inner wall surface (the other side in the direction of the axis O) of the front portion 43f and protrudes to the other side in the direction of the axis O. An output shaft 41 is passed through the center hole of the annular wall 43g, and a rolling bearing 44 is provided between the inner periphery of the other end of the annular wall 43g in the axis O direction and the outer periphery of the output shaft 41.

Regarding the main body casing 43, an annular wall 43d is erected on the inner wall surface (one side in the axis O direction) of the back surface portion 43b and protrudes in one direction in the axis O direction. A rolling bearing 46 is provided between the inner periphery of the annular wall 43d and the outer periphery of the other end of the output shaft 41 in the axis O direction. As a result, the output shaft 41 and the output gear 40 are both supported by the rolling

bearings

44 and 46. However, the rolling

bearings

44 and 46 are arranged away from the fixed outer ring 83 in the other direction of the axis O.

The carrier 18 has an upper arm portion 18a extending upward and a lower arm portion 18b extending downward as shown in FIG. The upper arm portion 18a protrudes upward beyond the main body casing 43, and is attached and fixed to the lower end portion 76b of the suspension member 76 (strut) by a bolt 78 at the tip portion. The lower arm portion 18b protrudes downward beyond the main body casing 43, and has a socket 62 for the ball joint 60 at the tip. The lower arm portion 18b changes its direction at the tip portion and extends in parallel with the axis O, and wraps directly under the wheel hub bearing portion 11. For this reason, the position of the socket 62 in the direction of the axis O overlaps the position of the fixed shaft 15 in the direction of the axis O. As shown in FIG. 6, the edge of the carrier 18 is formed in an arc 18 t corresponding to the outer peripheral surface of the motor unit 21. The concave arc 18t receives the motor casing 25. For this reason, the motor unit 21 does not interfere with the carrier 18.

Returning to FIG. 8, a plurality of extending portions 19 are formed on the carrier 18. With the upper arm portion 18a and the lower arm portion 18b as carrier bodies, the carrier body is disposed on the other side in the axis O direction than the wheel hub bearing portion 11, and the extending portion 19 extends from the carrier body to one side in the axis O direction. The position of the extending portion 19 in the axis O direction overlaps with the position of the main body casing 43 in the axis O direction, overlaps with the position of the output gear 40 in the axis O direction, overlaps with the position of the rotating inner ring 82 in the axis O direction, and the axis O of the fixed outer ring 83. It overlaps with the direction position and also overlaps with the position of the second row of rolling elements 14 in the direction of the axis O.

1 extension part 19 branches and extends from upper arm part 18a. The other extending portion 19 further extends from the tip of the lower arm portion 18b. A female screw hole to be screwed with the bolt 86 is formed at the tip of each extending portion 19. The bolt 86 extends in parallel with the axis O, the head is oriented in one direction of the axis O, the shaft is oriented in the other direction of the axis O and penetrates the hub attachment 85, and the tip region of the shaft is extended to the extended portion 19. Screwed into the provided female screw hole. The carrier 18, the hub attachment 85, and the fixed outer ring 83 are connected and fixed in series in this order by the

bolts

84 and 86.

The front end surface 19t of the extended portion 19 is abutted against and contacts the other surface of the hub attachment 85 in the axis O direction. Each tip 19t is flush. Regarding the position in the axis O direction, the position in the axis O direction of the front end surface 19t overlaps with the position in the axis O direction of the front portion 43f, or although not shown, it is one side in the axis O direction than the position in the axis O direction of the front portion 43f. Separated. Further, the position of the distal end surface 19 t in the axis O direction overlaps with the position of the fixed outer ring 83 in the axis O direction.

A through hole through which the bolt 87 is passed is formed on the inner diameter side of the hub attachment 85. A female screw hole that engages with the bolt 87 is formed in the front portion 43f. Such a female screw hole is provided inside the wall thickness of the annular wall 43g. The bolt 87 extends in parallel with the axis O, the head is oriented in one direction of the axis O, the shaft is oriented in the other direction of the axis O and penetrates the hub attachment 85, and the tip end region of the shaft is provided in the main body casing 43. The female screw hole is screwed. The carrier 18, the hub attachment 85, and the main body casing 43 are connected and fixed in series in this order by the

bolts

86 and 87.

In another embodiment shown in FIG. 8, a motor unit (not shown) is also arranged adjacent to the fixed outer ring 83 so that the offset distance from the axis O to the axis of the motor unit is shorter than before, and from the axis O as viewed in the direction of the axis O. The distance from the motor part to the stator can be shortened to ensure a sufficient outer diameter of the stator. This point should be understood by replacing the fixed shaft 15 with the fixed outer ring 83 with reference to FIG. Therefore, it is possible to secure a sufficient driving torque by ensuring a sufficient diameter of the motor portion.

The embodiment of the present invention has been described above with reference to the drawings, but the present invention is not limited to the illustrated embodiment. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention. In the present embodiment, the strut type suspension device 70 is illustrated, but the suspension device that couples the in-wheel motor driving device 10 to the vehicle body is not limited to the strut type. In the embodiment described above, the speed reducing unit 31 is a parallel four-shaft gear reducer. However, the number of parallel axes is not limited to this, and the speed reducing unit 31 may be a parallel twin-shaft gear reducer as an embodiment not shown. Alternatively, it may be a parallel triaxial gear reducer.

The in-wheel motor drive device according to the present invention is advantageously used in electric vehicles and hybrid vehicles.

10 in-wheel motor drive unit, 11 wheel hub bearing, 12 outer ring, 12f flange, 12s spline groove, 13 inner fixing member, 13b, 13c, 78 bolt, 14 rolling element, 15 fixed shaft, 15p protrusion, 15r root Part, 16 inner race, 18 carrier, 21 motor part, 22 motor rotating shaft, 25 motor casing, 25v motor casing cover, 44 rolling bearing (output shaft bearing), 31 reduction part, 32 input shaft, 33 input gear, 34, 36, 37, 39 Intermediate gear, 35, 38 Intermediate shaft, 40 Output gear, 41 Output shaft, 41s Spline groove, 43 Main body casing, 43b Rear portion (casing wall portion), 43bm One axial wall surface, 43bn Other axial wall surface , 43c 43f front part, 43p, 43q opening, 43z coupling seat part, 47 oil tank, 51 pump shaft, 53 pump gear, 54 oil pump, 60 ball joint, 61 ball stud, 61b ball part, 61s stud part, 62 socket, 70 suspension Device, 71, 76 Suspension member, 72 Outer end in the vehicle width direction, 73 End in the vehicle width direction, 76b Lower end, 76s Shock absorber, 77 Upper end region, BD Brake rotor, 82 Rotating inner ring, 83 Fixed outer ring, 85 Hub attachment, K Steering shaft, M, Nf, Nl, O, P axis S space, T tire, W wheel wheel, Wr rim part, Ws spoke part.

Claims

A motor part, a wheel hub bearing part, a speed reducing part that decelerates the rotation of the motor part and transmits it to the wheel hub bearing part, and a carrier for connecting to the vehicle body side member,
The wheel hub bearing portion includes an outer ring for coupling with a wheel disposed on one axial direction of the wheel hub bearing portion, a fixed shaft that is passed through a center hole of the outer ring, and an annular space between the outer ring and the fixed shaft. Having a plurality of rolling elements arranged in
The motor part and the speed reduction part are arranged offset in the direction perpendicular to the axis of the wheel hub bearing part,
The motor portion is disposed adjacent to the other end portion in the axial direction of the fixed shaft,
The speed reduction unit includes an output gear coupled to the outer ring, and a rolling bearing provided between the output gear and the fixed shaft and rotatably supporting the output gear,
The in-wheel motor drive device, wherein the carrier is disposed on the other axial direction other than the wheel hub bearing portion and is fixed to the other axial end of the fixed shaft.
2. The in-wheel motor drive device according to claim 1, wherein a casing wall portion of the speed reduction portion is disposed on the other side in the axial direction than the wheel hub bearing portion and is coupled to the other end portion in the axial direction of the fixed shaft.
The other axial end portion of the fixed shaft includes a projecting portion projecting in an outer diameter direction from the one axial end portion, and the projecting portion and the motor portion overlap each other when viewed in the axial direction of the wheel hub bearing portion. The in-wheel motor drive device of Claim 2 arrange | positioned.
The in-wheel motor drive device according to claim 3, wherein the protruding portion is fixed to one wall surface in the axial direction of the casing wall portion.
The in-wheel motor drive device according to claim 4, wherein the carrier is fixed to the other axial wall surface of the casing wall portion.
The wheel hub bearing portion further includes a bolt including a head portion oriented in one axial direction and a shaft portion oriented in the other axial direction,
6. The in-wheel motor drive device according to claim 4, wherein the shaft portion of the bolt penetrates the protruding portion and is screwed into a female screw hole provided in the casing wall portion.
A motor part, a wheel hub bearing part, a speed reducing part that decelerates the rotation of the motor part and transmits it to the wheel hub bearing part, and a carrier for connecting to the vehicle body side member,
The wheel hub bearing portion is arranged in a rotating inner ring for coupling with a wheel arranged in one axial direction, a fixed outer ring coaxially arranged on the outer diameter side of the rotating inner ring, and an annular space between the fixed outer ring and the rotating inner ring. Including a plurality of rolling elements,
The motor part and the speed reduction part are arranged offset in the direction perpendicular to the axis of the wheel hub bearing part,
The speed reduction portion includes an output gear coupled to the rotating inner ring, and a rolling bearing provided between the output gear and the rotating inner ring and rotatably supporting the output gear,
The in-wheel motor drive device, wherein the carrier includes a carrier body disposed on the other side in the axial direction than the wheel hub bearing portion, and an extending portion extending in the axial direction from the carrier body, and is fixed to the fixed outer ring by the extending portion. .
The wheel hub bearing portion includes a hub attachment that is coupled to the outer ring and projects outward from the outer ring.
The in-wheel motor drive device according to claim 7, wherein the extending portion of the carrier is attached and fixed to the hub attachment.