JP2018034584A - In-wheel motor drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for attaching and fixing a wheel hub bearing and a casing of an in-wheel motor drive unit to a vehicle body side member.SOLUTION: An in-wheel motor drive unit comprises: an outer ring which rotates integrally with wheels; an inside fixing member (13) arranged at an internal periphery of the outer ring; a wheel hub bearing part having a plurality of rolling bodies which are arranged in an annular clearance between the outer ring and the inside fixing member; a casing (43b) for rotatably supporting an input gear and/or an output gear; a hub carrier (18) connected to a vehicle body side member; and three-member common connecting means (13b) for connecting and fixing the inside fixing member, the hub carrier and the casing in a lump.SELECTED DRAWING: Figure 4

Description

  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 peripheral structure of 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 in which the wheel hub bearing of the in-wheel motor has a rotating outer ring and a fixed inner ring, for example, Japanese Patent Application Laid-Open No. 2008-44438 (Patent Document) 1) and those described in Japanese Patent Application Laid-Open No. 2008-184111 (Patent Document 2) are known. The in-wheel motor structure described in Patent Document 1 and Patent Document 2 includes a wheel wheel, an outer ring side member that is coaxially coupled to the wheel wheel, and an inner ring side member that is disposed coaxially on the inner diameter side of the outer ring side member. And two rows of angular ball bearings disposed between the outer inner ring side members, a simple planetary gear mechanism disposed coaxially on the inner diameter side of the inner ring side member, and a simple planetary gear mechanism and the outer inner ring side member. And a counter gear mechanism that is shifted in the direction of the axle and a motor that is offset in the direction perpendicular to the axle and arranged in parallel with the axle.

  The outer ring side member is a rotating member of the wheel hub bearing. The inner ring side member becomes a fixing member of the wheel hub bearing and is connected and fixed to the knuckle. The knuckle also serves as a casing that houses the motor and counter gear mechanism. The simple planetary gear mechanism is accommodated in the inner ring side member. The one end in the axle direction of the knuckle and the other end in the axle direction of the inner ring side member are connected by, for example, a bolt or the like, although not explicitly disclosed in the patent literature. Further, the outer peripheral wall surface of the knuckle is connected to the suspension device via a ball joint. The knuckle and the inner ring side member have sufficient wall thickness and high rigidity to support the wheel load of the vehicle.

JP 2008-44438 A JP 2008-184111 A

  In the conventional in-wheel motor, a wheel load is applied from the suspension device, a lateral force is applied from the wheel during turning, and the wheel load and the lateral force act on the knuckle. On the other hand, the knuckle supports a motor rotation shaft arranged offset from the axle, and each shaft of the simple planetary gear mechanism and the counter gear mechanism via bearings. For this reason, when the knuckle and the casing are integrated, it is necessary to sufficiently ensure the strength and rigidity of the knuckle so that the respective shafts do not shift due to wheel load and lateral force.

  When transmitting the rotation of the motor to the wheel side, it is required to enlarge or add gears in order to increase the reduction ratio. Since the in-wheel motor is accommodated in a limited space inside the wheel, the space limitation is large. For this reason, it is conceivable to increase the number of gears or increase the thickness by reducing the wall thickness of the outer portion of the in-wheel motor. However, in the conventional in-wheel motor, one part of the knuckle is connected and fixed to the inner ring side member by one connecting means such as a bolt, and another part of the knuckle is connected to the suspension device by another connecting means called a ball joint. Is responsible for wheel loads and lateral forces, it is difficult to reduce the wall thickness of the knuckle.

  In view of the above circumstances, the present invention relates to an in-wheel motor including a gear reducer, an improved structure for attaching and fixing an outer portion of the in-wheel motor to a vehicle body side member such as a suspension device, and a fixing member for a wheel hub bearing It is an object of the present invention to provide an improved structure for mounting and fixing a to a vehicle body side member.

  For this purpose, the in-wheel motor drive device according to the present invention includes an outer ring that rotates integrally with a wheel, an inner fixing member that is disposed on the inner periphery of the outer ring, and a plurality of rollers that are disposed in an annular gap between the outer ring and the inner fixing member. A wheel hub bearing portion having a moving body, a motor portion which is arranged offset from the axis of the wheel hub bearing portion and drives the outer ring, an input gear coupled to the motor rotation shaft of the motor portion, an output gear coupled to the outer ring, A reduction gear that has a casing that rotatably supports the input gear and / or the output gear, reduces the rotation of the input gear and transmits it to the output gear, a hub carrier that is connected to the vehicle body side member, and a hub carrier (knuckle) Comprises a separate member from the casing, and includes a three-member common connecting means for collectively connecting and fixing the three members of the inner fixing member, the hub carrier and the casing.

  According to the present invention, since the inner fixing member is connected and fixed to the hub carrier, the wheel load and the lateral force of the electric vehicle are supported by the hub carrier and the inner fixing member, and are not transmitted to the casing. The wall thickness can be made smaller than before. Further, since the casing is connected and fixed to the hub carrier, the casing firmly supports the gears of the speed reduction portion, and there is no possibility that the gears of the speed reduction portion are displaced from the axis of the wheel hub bearing portion. The three-member common connection means refers to, for example, a bolt that penetrates the three stacked members, and the three members are fixed by tightening the bolt. Alternatively, the three-member common connecting means refers to, for example, an unevenness formed on the surfaces of two adjacent members, and a fixture that fits at least two members and prohibits relative movement of the two members, and the remaining one member Is fixed to the two members by an uneven shape. The vehicle body side member refers to a member on the vehicle body side as viewed from a member to be described, here, a hub carrier, for example, a suspension device.

  The arrangement relationship between the inner fixing member, the hub carrier, and the casing is not particularly limited. However, as one embodiment of the present invention, the wall portion of the casing is interposed between the inner fixing member and the hub carrier, and the three-member common connecting means is provided on the inner side. A first through hole formed in one of the fixing member and the hub carrier, a second through hole formed in a wall portion of the casing, and a first female screw formed on the other remaining side of the inner fixing member and the hub carrier And a first bolt that penetrates the first and second through holes and is screwed into the first female screw. According to such an embodiment, the inner fixing member, the casing, and the hub carrier can be connected and fixed together. In another embodiment, the inner fixing member may be interposed between the wall portion of the casing and the hub carrier. Alternatively, as another embodiment, a hub carrier may be interposed between the wall portion of the casing and the inner fixing member.

  As a preferred embodiment of the present invention, the three-member common connecting means has an outer peripheral surface and an inner peripheral surface, and the outer peripheral surface is fitted with a second through-hole formed in the wall portion of the casing, and the inner peripheral surface is the first bolt. It further includes an intermediate member that surrounds the outer periphery, and a first seal member interposed between the intermediate member and the wall portion of the casing. According to this embodiment, even if the first bolt is loosened at the time of overhauling and the like, the lubricating oil inside the casing is prevented from leaking from the second through hole. As another embodiment, only the first bolt may be passed through the second through hole without providing the intermediate member. Alternatively, as another embodiment, the first sealing member may not be provided, and a sealing material may be interposed between the inner fixing member and the wall portion of the casing.

  As a further preferred embodiment of the present invention, the first through hole is formed in the hub carrier, the first female screw is a bottomed hole formed in the inner fixing member, and the three-member common connecting means includes an intermediate member and an inner fixing member. A second sealant interposed between the two. According to this embodiment, the lubricating oil inside the casing is prevented from leaking out of the casing along the outer peripheral surface of the first bolt. As another embodiment, the second seal member may be omitted, or the first female screw may be bottomless.

  As one embodiment of the present invention, a third through hole formed in the inner fixing member, a bottomed second female screw hole formed in the casing, and a screw through the third through hole to the second female screw hole And a second bolt. According to this embodiment, the second bolt can be completely accommodated inside the casing. Therefore, the lubricating oil inside the casing does not leak out of the casing along the outer peripheral surface of the second bolt. In addition, the second female screw hole and the second bolt and the first seal material are combined, so that the inner fixing member can be fixed to the casing even if the first bolt is loosened. Moreover, even if the second female screw hole and the second bolt are combined with the second sealing material and the first female screw having the bottom, the inner fixing member can be fixed to the casing even if the first bolt is loosened and extracted. The inner fixing member and the casing can be separated while the second through hole is sealed. Therefore, the lubricating oil inside the casing does not leak from the inner peripheral surface of the intermediate member to the outside of the casing.

  As an embodiment of the present invention, the three-member common connecting means further includes intermediate member movement restricting means for restricting the intermediate member from moving toward the hub carrier. According to this embodiment, the intermediate member is prevented from coming out of the second through hole in the wall portion. Further, the second female screw hole and the second bolt for fixing the inner fixing member to the one wall surface of the casing and the intermediate member movement restricting means combine to fix the intermediate member to the wall portion even if the first bolt is loosened. be able to.

  As an embodiment of the present invention, the intermediate member and the hub carrier are in contact with each other, and the hub carrier is disposed apart from the casing. According to this embodiment, even if an excessive external force acts on the hub carrier, the intermediate member, and the inner fixing member to deform them, the casing is not deformed. Therefore, the disadvantage that the shafts supported by the casing are displaced can be further suppressed.

  As one embodiment of the present invention, the speed reduction portion further includes a plurality of intermediate gears arranged offset from the axis of the motor rotation shaft and the wheel hub bearing portion, and the rotation of the input gear is reduced and output via the intermediate gear. The gear is transmitted to the gear, and the casing rotatably supports the intermediate gear. According to this embodiment, since the intermediate gear is provided, the reduction ratio of the reduction unit can be increased. A casing that rotatably supports the intermediate gear is firmly fixed to the hub carrier. As a result, it is possible to prevent inconveniences such as a shift in the arrangement relationship between the axis of the intermediate gear and the wheel hub bearing portion.

  Thus, according to the present invention, the inner fixing member is connected and fixed to the hub carrier by the three-member common connecting means, and the casing is connected and fixed to the hub carrier by the three-member common connecting means. There is no possibility that the gear of the speed reduction part is displaced with respect to the axis of the wheel hub bearing part by firmly supporting the gear. Further, the wheel load and the lateral force of the wheel of the electric vehicle are supported by the hub carrier and the inner fixing member and are not transmitted to the casing, so that the thickness of the casing can be made smaller than before. Therefore, an intermediate gear can be added in a limited space of wheel wheels, and the in-wheel motor drive device can be reduced in weight.

It is a schematic diagram which shows the in-wheel motor drive device which becomes one Embodiment of this invention, and represents the state seen from the vehicle width direction outer side. It is a cross-sectional view which shows typically the in-wheel motor drive device of the embodiment. It is an expanded sectional view showing typically the in-wheel motor drive device of the embodiment. It is sectional drawing which expands and shows the 3 member common connection means of the embodiment. It is an expanded sectional view showing typically the in-wheel motor drive which becomes other embodiments of the present invention. It is sectional drawing which expands and shows the 3 member common connection means of other embodiment. It is an expanded sectional view showing an in-wheel motor drive of a reference example typically.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing an in-wheel motor drive device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing the in-wheel motor drive device of the first embodiment. 1 and 2 show a state seen from the outside in the vehicle width direction. In FIG. 2, each gear in the speed reduction unit is represented by a tip circle, and individual teeth are omitted. FIG. 3 is a developed cross-sectional view schematically showing the in-wheel motor drive device of the first embodiment. 3 includes a plane including the axis M and the axis Nf, a plane including the axis Nf and the axis Nl, a plane including the axis Nl and the axis O, an axis O and the axis P illustrated in FIG. It is the expansion | deployment plane which connected the plane which contains in this order.

  The in-wheel motor drive device 10 includes a wheel hub bearing portion 11, a motor portion 21, and a speed reducing portion 31 that decelerates the rotation of the motor portion 21 and transmits it to the wheel hub bearing portion 11, and is an electric vehicle (not shown). Are arranged symmetrically on both the left and right sides in the vehicle width direction. At this time, as shown in FIG. 3, the wheel hub bearing portion 11 is disposed on the outer side in the vehicle width direction, and the motor portion 21 is disposed on the inner side in the vehicle width direction.

  The in-wheel motor drive device 10 is disposed in the inner space of the wheel wheel W represented by the phantom line in FIG. 1 and is connected to the center of the wheel wheel W represented by the phantom line in FIG. The wheel W is driven.

  Each in-wheel motor drive device 10 is connected to the vehicle body of the electric vehicle via a suspension device (not shown). 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 motor part 21 and the speed reduction part 31 are not arranged coaxially with the axis O of the wheel hub bearing part 11 as shown in FIGS. 1 and 2, but are perpendicular to the axis O of the wheel hub bearing part 11 as shown in FIG. It is arranged offset. In other words, the in-wheel motor drive device 10 will be described in detail later, but a part disposed forward of the vehicle, a part disposed rearward of the vehicle, a part disposed above, and a part disposed below. including.

  As shown in FIG. 3, the wheel hub bearing portion 11 includes an outer ring 12 as a wheel hub coupled to the wheel wheel W, an inner fixing member 13 that is passed through a center hole of the outer ring 12, an outer ring 12, and an inner fixing member 13. A plurality of rolling elements 14 disposed in the annular gap are configured to constitute an axle. The inner fixing member 13 includes a non-rotating fixing shaft 15, a pair of inner races 16, a retaining nut 17, and a hub carrier 18. 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 penetrates the main body casing 43 that forms the outline of the speed reduction portion 31. The tip 15e of the fixed shaft 15 passes through an opening 43p formed in the front portion 43f of the main body casing 43, and protrudes outward in the vehicle width direction from the front portion 43f. The root portion 15r of the fixed shaft 15 is covered with the back surface portion 43b of the main body casing 43 from the inner side in the vehicle width direction. The front portion 43f and the rear portion 43b are casing wall portions facing each other with an interval in the direction of the axis O. A hub carrier 18 is attached and fixed to the root portion 15r by connecting means described later. The hub carrier 18 is connected to a suspension device and a tie rod (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 axis O direction, and the vehicle width direction inner side (inboard side) is also referred to as the other axis O direction. The left-right direction in FIG. 3 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 the brake disc BD and the spoke portion Ws of the wheel / wheel W. The outer ring 12 is coupled to the brake disc BD and the wheel wheel W at the flange portion 12f, and rotates integrally with the wheel wheel W. As a modification not shown, the flange portion 12f may be a protruding portion that protrudes toward the outer diameter side with an interval in the circumferential direction.

  As shown in FIG. 3, the motor unit 21 includes a motor rotation shaft 22, a rotor 23, a stator 24, and a motor casing 25, which are sequentially arranged from the axis M of the motor unit 21 to the outer diameter side in this order. 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.

  An axis M serving as 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 tip 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. Specifically, one end of the input shaft 32 in the axis M direction is supported by the front portion 43f via the rolling bearing 42a, and the other end of the input shaft 32 in the axis M direction is supported by the back surface portion 43b via the rolling bearing 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.

  One end of the output shaft 41 in the axis O direction is supported by the main body casing 43 via the 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 vehicle longitudinal direction position of each axis will be described. As shown in FIG. 2, the axis M of the input shaft 32 is disposed ahead of 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 an unillustrated modification, the axis M of the input shaft 32 is arranged at an arbitrary position around the axis O, and the input shaft 32, the intermediate shaft 35, the intermediate shaft 38, and the output shaft 41 are arranged in this order in the vehicle longitudinal direction. It may be arranged. In this case, the vertical position of each axis is determined by the longitudinal position and vertical position of the motor unit 21. The shafts 32, 35, 38, and 41 constitute the driving force transmission order in this order.

  Explaining the vertical position of each axis, the axis M of the input shaft 32 and the axis O of the output shaft 41 are arranged at substantially the same vertical position. 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. It is sufficient that the plurality of intermediate shafts 35 and 38 are 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. In the modification in which the axis M of the input shaft 32 is arranged at the arbitrary position described above around the axis O, the vertical positions of the input shaft 32, the intermediate shaft 35, the intermediate shaft 38, and the output shaft 41 are motors. Determined by the position in the front-rear direction and the position in the vertical direction.

  The intermediate gear 34 and the intermediate gear 36 are external gears, and are coupled coaxially with the central portion in the direction of the axis Nf of the intermediate shaft 35 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. Specifically, one end of the intermediate shaft 35 in the axis Nf direction is supported by the front portion 43f via the rolling bearing 45a, and the other end of the intermediate shaft 35 in the axis Nf direction is supported by the back surface portion 43b via the rolling bearing 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. Specifically, one end of the intermediate shaft 38 in the axis Nl direction is supported by the front portion 43f via the rolling bearing 48a, and the other end of the intermediate shaft 38 in the axis Nl direction is supported by the back surface portion 43b via the rolling bearing 48b. .

  The main body casing 43 forms an outer shell of the speed reduction portion 31 and the wheel hub bearing portion 11 and is formed in a cylindrical shape so as to surround 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 (FIG. 1). As shown in FIG. 3, the inner space of the wheel W is partitioned 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, main body casing 43 protrudes downward at a position away from axis O of output gear 40 in the vehicle front-rear direction, specifically, just below axis M of input gear 33. This protruding portion forms an oil tank 47. On the other hand, a space is secured between the portion 43c of the main body casing 43 directly below the axis O and the lower portion of the rim portion Wr. A suspension member (not shown) extending in the vehicle width direction is arranged in the space, and the outer end of the suspension member in the vehicle width direction and the hub carrier 18 are connected to each other through a ball joint.

  The main body casing 43 has a cylindrical shape, and as shown in FIG. 3, 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. 3, 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. Further, the back surface portion 43 b is coupled to a suspension member (not shown) such as an arm or a strut via the hub carrier 18. Thereby, the in-wheel motor drive device 10 is connected to the suspension device. The arms, struts, and the like of the suspension device are also referred to as vehicle body side members because they are attached to the vehicle body side as viewed from the members to be described, here the in-wheel motor drive device 10. Since the main body casing 43, the motor casing 25, and the motor casing cover 25v are connected to the vehicle body side member via the hub carrier 18, they are separated from the vehicle body side 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 small-diameter input gear 33 and the large-diameter intermediate gear 34 are arranged on one side (flange portion 12f side) in the axial direction of the speed reduction portion 31 and mesh with each other. The small-diameter intermediate gear 36 and the large-diameter intermediate gear 37 are disposed on the other side in the axial direction of the speed reduction unit 31 (on the motor unit 21 side) and mesh with each other. The small-diameter intermediate gear 39 and the large-diameter output gear 40 are arranged on one side in the axial direction (flange portion 12f side) of the speed reduction portion 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 output by the meshing of the drive side small gear and the driven large diameter gear. Decelerated by the shaft 41. 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.

  According to the present embodiment, as shown in FIG. 2, the output shaft 41, the intermediate shaft 38, and the input shaft 32 are arranged in this order with an interval in the vehicle front-rear direction. Further, the intermediate shaft 35 and the intermediate shaft 38 are disposed above the input shaft 32 and the output shaft 41. According to this embodiment, the intermediate shaft can be arranged above the outer ring 12 that becomes the wheel hub, and a space for arranging the oil tank 47 can be secured below the outer ring 12, or a space can be secured just below the outer ring 12. can do. Therefore, the turning shaft extending in the vertical direction can be provided so as to intersect the space directly below the outer wheel 12, 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 unit 21 is arranged offset from the axis O of the wheel hub bearing in the vehicle front-rear direction, and the axis Nf of the intermediate shaft 35 is arranged as the wheel hub bearing. The axis Nl of the intermediate shaft 38 is offset upward from the axis O of the wheel hub bearing portion. Thereby, a space can be ensured between the portion 43 c directly below the axis O in the in-wheel motor drive device 10 and the lower portion of the wheel W. 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. 3, 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. 3, the outer ring 12 serving as 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. The driving force can be transmitted to the outer ring 12 from the intermediate shaft 38 that is arranged offset from the outer ring 12.

  As shown in FIG. 3, the main body casing 43 further houses a pump shaft 51, rolling bearings 52 a and 52 b, a pump gear 53, and an oil pump 54. 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 rotatably supported on both sides of the axis P direction via rolling bearings 52a and 52b, and is coaxial with the pump gear 53 at the center of the axis P direction. Join. The pump gear 53 is an external gear, a helical gear, and meshes with the output gear 40 and is driven by 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. The oil pump 54 is connected to the suction oil passage 59i and the discharge oil passage 59o shown in FIG. The suction oil passage 59 i extends downward from the oil pump and reaches the oil tank 47, and the suction port 59 j at the lower end of the suction oil passage 59 i is disposed near the bottom wall of the oil tank 47. The discharge oil passage 59 o extends upward from the oil pump, and the discharge port 59 p at the upper end of the discharge oil passage 59 o is disposed at a position higher than the intermediate gear 37.

  When the oil pump 54 is driven by the output gear 40, the oil pump 54 sucks the lubricating oil in the oil tank 47 from the suction port 59j, and discharges the sucked lubricating oil through the discharge port 59p. The discharge port 59p is positioned higher than all the gears (the input gear 33, the intermediate gears 34, 36, 37, 39, and the output gear 40), and supplies lubricating oil to these gears from above. Lubricating oil is injected into the motor unit 21 from the discharge oil passage 59o. Thereby, the motor part 21 and the deceleration part 31 are lubricated and cooled.

  With reference to FIG. 2, the pump shaft 51 of this 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 wheel W is driven by the in-wheel motor drive device 10 and the electric vehicle travels, the oil tank 47 receives the traveling wind from the front of the vehicle and is air-cooled.

  Next, means for connecting the main casing 43 and the inner fixing member 13 will be described.

  As shown in FIG. 3, the inner fixing member 13 is disposed on one axial side with respect to the rear portion 43 b of the main body casing 43, and the hub carrier 18 is disposed on the other axial direction with respect to the rear portion 43 b. Between the motor part 21 and the speed reduction part 31 and between the motor part 21 and the wheel hub bearing part 11, a back surface part 43 b is interposed. The back surface portion 43 b is a casing wall portion that covers the other end of the speed reduction portion 31 and the wheel hub bearing portion 11 in the axis O direction.

  The other end surface 15n in the axis O direction located on the other side in the axis O direction of the fixed shaft 15 is fixed to the one wall surface 43bm in the axis O direction of the back surface portion 43b. 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. Specifically, a through hole 15h is formed in the protruding portion 15p. A bottomed female screw hole 43t directed to the other axial direction is formed in the back surface portion 43b. 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 through hole 15h of the projecting portion 15p. Screwed into the hole 43t. The bolt 13 c is accommodated in the main body casing 43.

  If it adds here, the wheel hub bearing part 11 will be arrange | positioned rather than the back surface part 43b at the axis line O direction one side. 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.

  Next, a three-member common connecting means for connecting the main body casing 43, the inner fixing member 13 and the hub carrier 18 together will be described.

  As shown in FIG. 3, a back surface portion 43 b as a wall portion of the main body casing 43 is interposed between the inner fixing member 13 and the hub carrier 18. The three members of the inner fixing member 13, the back surface portion 43b, and the hub carrier 18 are arranged adjacent to each other in the axis O direction in this order, and are connected and fixed together by a bolt 13b as a three-member common connecting means.

  FIG. 4 is an enlarged view of the encircled portion of the alternate long and short dash line in FIG. 3, and represents a three-member common connecting means for connecting and fixing the inner fixing member 13, the hub carrier 18, and the main body casing 43 together. A first through hole 18 h is formed in the hub carrier 18. A second through hole 43h is formed in the back surface portion 43b. The bolt 13b is screwed into a bottomed female screw hole 15t formed in the protruding portion 15p through the first through hole 18h and the second through hole 43h. In the present embodiment, the shaft portion of the bolt 13b is directed to one side in the axis O direction, and the head portion of the bolt 13b is directed to the other side in the axis O direction.

  In the shaft portion of the bolt 13b, a male screw is formed only on the outer peripheral surface of the tip portion, and the cross section from the central region of the shaft portion to the lower neck portion is a circle having a constant outer diameter. For this reason, the bolt 13b is screwed into the inner fixing member 13 at the tip portion, and is passed through the inner peripheral surface 19n and the first through hole 18h, which are round holes, from the central region of the shaft portion to the lower neck portion. The inner diameters of the inner peripheral surface 19n and the first through hole 18h are set to dimensions corresponding to the outer diameter of the bolt 13b shaft portion.

  The material of the main casing 43 is made of aluminum or an alloy mainly composed of light metal. An intermediate member 19 is provided in the second through hole 43 h of the main body casing 43. The intermediate member 19 is considered as a component part of the three-member common connecting means, and is sandwiched between the inner fixing member 13 and the hub carrier 18 while being engaged with the main body casing 43, and the main body casing 43 is held between the inner fixing member 13 and the hub carrier 18. Fix it. The material of the intermediate member 19 is made of iron, an alloy containing iron as a main component, aluminum, or an alloy containing aluminum as a main component. The intermediate member 19 is a cylindrical member having a flat one end surface 19l, a flat other end surface 19m, an inner peripheral surface 19n, and an outer peripheral surface 19s. The outer peripheral surface 19s of the intermediate member 19 is fitted to the inner periphery of the second through hole 43h. The inner peripheral surface 19n defines a central hole of the intermediate member 19, and the shaft portion of the bolt 13b is passed through. Thereby, the intermediate member 19 surrounds the outer periphery of the shaft portion of the bolt 13b.

  The outer peripheral surface 19s of the intermediate member 19 has a large diameter at one end in the axial direction and a small diameter at the other end in the axial direction. Therefore, an annular step 19t is formed on the outer peripheral surface 19s. The step 19t is directed to the other end in the axial direction. An annular step 43r corresponding to the step 19t is formed on the inner peripheral surface of the second through hole 43h. The step 19t is directed to one end in the axial direction. The step 19t of the intermediate member 19 engages with a step 43r formed on the inner peripheral surface of the second through hole 43h. As a result, the intermediate member 19 is restricted from moving in the other axial direction, and is prevented from coming out of the main body casing 43.

  The first sealing material 13d is interposed between the intermediate member 19 and the back surface portion 43b. The first sealing material 13 d is, for example, an annular O-ring, and is attached to the outer peripheral surface 19 s of the intermediate member 19 to surround the intermediate member 19. A second sealing material 13 f is interposed between the intermediate member 19 and the inner fixing member 13. The second sealing material 13f is, for example, an annular O-ring, is provided along one end surface 19l of the intermediate member 19, and surrounds the outer periphery of the shaft portion of the bolt 13b. By the first sealing material 13d and the second sealing material 13f, the gap between the back surface portion 43b and the counterpart material is sealed, and the lubricating oil is prevented from leaking from the internal space of the main body casing 43 to the outside of the main body casing 43.

  When the bolt 13 b is fastened, the other end surface 19 m of the intermediate member 19 comes into surface contact with the flat surface 18 l of the hub carrier 18. Since the flat surface 181 protrudes from the periphery of the hub carrier 18, a gap C is secured between the hub carrier 18 and the back surface portion 43 b, and the hub carrier 18 is separated from the main body casing 43.

  By the way, according to the present embodiment, the first bolt 13b and the first through-hole 18h are used as the three-member common connecting means for the in-wheel motor driving device 10 to join the inner fixing member 13, the hub carrier 18 and the main body casing 43 together. Since the second through hole 43h and the female screw hole 15t are provided, the inner fixing member 13 is firmly fixed to the hub carrier 18. Accordingly, the wheel load and lateral force of the electric vehicle that the inner fixing member 13 and the hub carrier 18 handle are not applied to the main body casing 43, and the thickness of the main body casing 43 can be made smaller than before. In addition, since the main casing 43 is firmly fixed to the hub carrier 18, the main casing 43 firmly supports the input shaft 32, the intermediate shafts 35 and 38, and the output shaft 41 via the rolling bearing, and the speed reducing portion 31. There is no possibility that each of the shafts is shifted from the axis O of the wheel hub bearing portion 11.

  Further, according to the present embodiment, the back surface portion 43b, which is the wall portion of the main body casing 43, is interposed between the inner fixing member 13 and the hub carrier 18, and the three-member common connecting means is used for the inner fixing member 13 and the hub carrier 18. The first through hole 18h formed in any one of the first through hole 43h, the second through hole 43h formed in the back surface portion 43b, and the inner fixing member 13 and the hub carrier 18 through the first and second through holes. Since it includes the bolt 13b that is screwed into the first female screw hole 15t formed on the other side, the inner fixing member 13 inside the main body casing 43, the main body casing 43 itself, and the hub carrier 18 outside the main body casing 43, that is, The three members can be connected and fixed together.

  As a modification (not shown), the three-member common connecting means includes a first through hole formed in the inner fixing member 13, a second through hole 43h formed in the back surface portion 43b, and the first and second through holes. A bolt that passes through the hole and is screwed into a first female screw formed in the hub carrier 18 may be included.

  Further, according to the present embodiment, the outer peripheral surface 19s has the outer peripheral surface 19s and the inner peripheral surface 19n, and the outer peripheral surface 19s is fitted to the inner periphery of the second through hole 43h formed in the back surface portion 43b, and the inner peripheral surface 19n is the bolt 13b. The intermediate member 19 surrounding the outer periphery of the main body casing 43 and the first seal member 13d interposed between the intermediate member 19 and the back surface portion 43b are further provided. The internal lubricating oil is prevented from leaking from the second through hole 43h. Further, according to the present embodiment, the first through hole 18h is formed in the hub carrier 18, the first female screw hole 15t is a bottomed hole formed in the inner fixing member 13, and the intermediate member 19 and the inner fixing member. Since the second sealing material 13f interposed between the first casing 13 and the second casing 13 is further provided, it is possible to prevent the lubricating oil inside the main casing 43 from leaking out of the main casing 43 along the outer peripheral surface of the first bolt 13b.

  Further, according to the present embodiment, the third through hole 15 h formed in the inner fixing member 13, the bottomed second female screw hole 43 t formed in the back surface portion 43 b of the main body casing 43, and the third through hole Since the second bolt 13c is further provided through the hole 15h and screwed into the second female screw hole 43t, the second bolt 13c is completely accommodated in the main body casing 43. Therefore, the lubricating oil inside the main body casing 43 does not leak out of the main body casing 43 along the outer peripheral surface of the second bolt 13c. Further, the female screw hole 43t, the bolt 13c, and the first sealing material 13d are combined, so that the inner fixing member 13 can be fixed to the main body casing 43 even if the bolt 13b is loosened and extracted, and the second through hole 43h. It is possible to separate the inner fixing member 13 and the main body casing 43 while sealing. Further, the female screw hole 43t and the bolt 13c, the second sealing material 13f and the bottomed female screw hole 15t are combined, so that the inner fixing member 13 can be fixed to the main body casing 43 even if the bolt 13b is loosened and extracted. The lubricating oil inside the main body casing 43 does not leak out from the inner peripheral surface 19n of the intermediate member 19 to the outside of the main body casing 43.

  Further, according to the present embodiment, the intermediate member movement restricting means is provided at the fitting position where the intermediate member 19 is fitted into the main body casing 43. The steps 19t and 43r as intermediate member movement restricting means restrict the intermediate member 19 from moving toward the hub carrier 18 side. Thereby, it can prevent that the intermediate member 19 slips out from the back surface part 43b. Further, the female screw hole 43t and the bolt 13c for fixing the inner fixing member 13 to the one wall surface 43bm in the axis O direction, the step 19t directed to the other in the axis O direction, and the step 43r directed in the one direction in the axis O are combined. The intermediate member 19 can be fixed to the back surface portion 43b even if it is loosened and extracted.

  The intermediate member movement restricting means of the present embodiment includes the step 19t of the intermediate member and the step 43r of the main body casing 43. However, as a modification not shown, for example, the step 43r is not provided, and the step 19t is related to the one wall surface 43bm in the axis O direction. May be combined.

  Further, according to the present embodiment, the intermediate member 19 and the hub carrier 18 are in contact with each other, and the hub carrier 18 is disposed away from the back surface portion 43b by the gap C. Even if they act on the member 19 and the inner fixing member 13 and are deformed, the back surface portion 43b is not deformed. Therefore, there is no possibility that the main casing 43 is deformed by an excessive external force or the like.

  In addition, according to the present embodiment, the main body casing 43 rotatably supports the input shaft 32 and the plurality of intermediate shafts 35 and 38 via the rolling bearings 42a, 42b, 45a, 45b, 48a, and 48b. Is firmly fixed to the hub carrier 18, there is no possibility that the main body casing 43 moves due to the radial load of the input shaft 32 and the intermediate shafts 35, 38, and inconveniences such as displacement of the axes M, Nf, Nl are eliminated. . In particular, with respect to a load input from the outside (wheel wheel W or the like) to the in-wheel motor drive device 10 through the outer ring 12 (wheel hub), the three-member common connection means of this embodiment can be used to drive the in-wheel motor. It is possible to prevent the external input load from being received by the casing (main body casing) of the apparatus 10.

  The effect of the present embodiment will be supplementarily explained in comparison with the reference example. FIG. 7 is a developed cross-sectional view showing an in-wheel motor drive device 30 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, means for connecting and fixing the inner fixing member 13 and the hub carrier 18 are provided instead of means for connecting and fixing the inner fixing member 13, the main body casing 43, and the hub carrier 18 together.

  A large-diameter opening 43q through which the inner fixing member 13 is passed is formed in the back surface portion 43b. As shown in FIG. 3, the root portion 15r of the inner fixing member 13 is not disposed in the main body casing 43 with respect to the one side in the axis O direction than the back surface portion 43b and is accommodated inside the main body casing 43. And is located outside the main casing 43. A bottomless female screw hole 15u is formed in the protruding portion 15p protruding in the direction perpendicular to the axis O from the root portion 15r.

  The bolt 13b is passed through the first through hole 18h of the hub carrier 18 from the other side in the axis O direction and screwed into the female screw hole 15u. Thus, the bolt 13b connects and fixes the inner fixing member 13 and the hub carrier 18. Note that the bolt 13b is spaced apart from the other side in the direction of the axis O of the back surface portion 43b.

  A bottomed female screw hole 43u is formed in the other surface 43bn in the axis O direction of the back surface portion 43b. The bolt 13 c has the shaft portion 13 ct on one side in the axis O direction, the head portion 13 cd on the other side in the axis O direction, passes through the protruding portion 15 p, and is screwed into the female screw hole 43 u of the main body casing 43. The bolt 13c shown in FIG. 7 is opposite in direction to the bolt 13c shown in FIG. 3 and is arranged outside the main body casing 43, but is common in that the inner fixing member 13 and the main body casing 43 are connected and fixed to each other.

  A sealing material 49 is interposed between the outer peripheral surface of the root portion 15r and the inner peripheral surface of the opening 43q. The sealing material 49 is, for example, an annular O-ring, and seals the annular gap between the root portion 15r and the opening 43q. This prevents the lubricating oil inside the main body casing 43 from flowing along the outer peripheral surface of the root portion 15r and leaking out of the main body casing 43.

  When the speed reduction part 31 is a parallel 4-axis type reduction gear as in the reference example, or when the number of intermediate gears is increased, the intermediate shaft coupled to each intermediate gear is rotatably supported by the main body casing 43 of the in-wheel motor drive device. It will be. For this reason, it is necessary to ensure rigidity by increasing the wall thickness of the casing so that the intermediate shaft does not shift.

  In the reference example, the fixed shaft 15 of the inner fixing member 13 passes through the back surface portion 43 b of the main body casing 43 and is fixed to the hub carrier 18. For this reason, the back surface portion 43b is largely lost (missed) by the area of the opening 43q. Therefore, the strength and rigidity of the main body casing 43 is reduced, and when the input shaft 32 and the intermediate shafts 35 and 38 supported by the main body casing 43 are rotated, the torque acting on each shaft and the tooth surface acting on the gear tooth surface. The misalignment of each axis occurs due to the load, and there is concern about the short life of each gear due to sound vibration caused by local tooth contact and partial high surface pressure.

  On the other hand, according to the embodiment shown in FIG. 3, the fixed shaft 15 of the inner fixing member 13 is arranged on one side in the axis O direction with respect to the back surface portion 43 b of the main body casing 43, so that the back surface portion 43 b has a small diameter. The through-hole 43h is sufficient, and there is no large omission in the back surface portion 43b. Therefore, the strength and rigidity of the main body casing 43 are ensured, and the life of each gear is not impaired.

  Next, another embodiment of the present invention will be described.

  FIG. 5 is a developed cross-sectional view showing another embodiment. FIG. 6 is an enlarged view of the encircled portion of the alternate long and short dash line in FIG. 5 and represents a three-member common connecting means for connecting and fixing the inner fixing member 13, the hub carrier 18, and the main body casing 43 together. Regarding the other embodiments, the same reference numerals are given to the configurations common to the above-described embodiments, and the description thereof will be omitted, and different configurations will be described below. In another embodiment, the intermediate member is not provided in the second through hole 43h of the main body casing 43, which is simpler than the embodiment shown in FIG. The inner diameter of the second through hole 43h according to another embodiment is set to a size corresponding to the outer diameter of the bolt 13b shaft portion. Only the bolt 13b is passed through the second through hole 43h.

  Since the flat surface 18l of the hub carrier 18 is formed so as to protrude from the periphery of the hub carrier 18, a gap D (FIG. 6) is secured between the periphery of the flat surface 18l of the hub carrier 18 and the back surface portion 43b.

  The in-wheel motor drive device 20 shown in FIGS. 5 and 6 also has a first bolt 13b and a first through hole 18h as a three-member common connecting means for connecting the inner fixing member 13, the hub carrier 18 and the main body casing 43 together. Since the second through hole 43h and the female screw hole 15t are provided, the inner fixing member 13 is firmly fixed to the hub carrier 18 via the peripheral part of the second through hole 43h of the back surface portion 43b. 18 directly and firmly fixed. Therefore, the wheel load of the electric vehicle that the inner fixing member 13 takes over is not applied to the main body casing 43, and the thickness of the main body casing 43 can be made smaller than before.

  Although the embodiments of the present invention have been described with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

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

10, 20, 30 in-wheel motor drive device, 11 wheel hub bearing,
12 outer ring, 13 inner fixing member, 13b first bolt,
13c second bolt, 13d first sealing material,
13f 2nd sealing material, 15 fixed axis | shaft, 15h 3rd through-hole,
15p protrusion, 15r root, 15t first female screw hole,
15u female screw hole, 18 hub carrier, 18h first through hole,
18l flat surface, 19 intermediate member, 19l one end surface,
19m other end surface, 19n inner peripheral surface (center hole), 19s outer peripheral surface,
19t step, 21 motor part, 31 reduction part,
43 main body casing, 43b back surface part, 43bm one wall surface,
43r step, 43h second through hole, 43t second female screw hole,
C, D clearance, M, Nf, Nl, O, P axis, W wheel wheel.

Claims (8)

A wheel hub bearing having an outer ring that rotates integrally with a wheel, an inner fixing member disposed on an inner periphery of the outer ring, and a plurality of rolling elements disposed in an annular gap between the outer ring and the inner fixing member;
A motor unit that is arranged offset from the axis of the wheel hub bearing unit and drives the outer ring;
An input gear coupled to the motor rotation shaft of the motor unit; an output gear coupled to the outer ring; a casing that rotatably supports the input gear and / or the output gear; and the rotation of the input gear is reduced. A speed reducer that transmits to the output gear;
A hub carrier connected to the vehicle body side member;
An in-wheel motor drive device comprising: a three-member common connection means for collectively connecting and fixing the three members of the inner fixing member, the hub carrier, and the casing together. A wall portion of the casing is interposed between the inner fixing member and the hub carrier;
The three-member common connection means includes a first through hole formed in one of the inner fixing member and the hub carrier, a second through hole formed in the wall portion, the inner fixing member, and the hub. 2. The in-wheel motor drive according to claim 1, comprising: a first female screw formed on the other remaining carrier and a first bolt that passes through the first and second through holes and is screwed into the first female screw. apparatus. The three-member common connecting means is
An intermediate member having an outer peripheral surface and an inner peripheral surface, the outer peripheral surface fitting with the second through-hole formed in the wall portion, and the inner peripheral surface surrounding the outer periphery of the first bolt;
The in-wheel motor drive device according to claim 2, further comprising a first seal member interposed between the intermediate member and the wall portion. The first through hole is formed in the hub carrier,
The first female screw is a bottomed hole formed in the inner fixing member,
4. The in-wheel motor drive device according to claim 3, wherein the three-member common connection means further includes a second seal member interposed between the intermediate member and the inner fixing member.   A third through hole formed in the inner fixing member, a bottomed second female screw hole formed in the casing, and a second bolt that passes through the third through hole and is screwed into the second female screw hole. The in-wheel motor drive device according to claim 4, further comprising:   The in-wheel motor drive device according to any one of claims 3 to 5, wherein the three-member common connecting means further includes intermediate member movement restricting means for restricting movement of the intermediate member toward the hub carrier.   The in-wheel motor drive device according to any one of claims 3 to 6, wherein the intermediate member and the hub carrier are in contact with each other, and the hub carrier is disposed apart from the casing. The speed reduction part further includes a plurality of intermediate gears arranged offset from the axis of the motor rotation shaft and the wheel hub bearing part, and the output gear reduces the rotation of the input gear via the intermediate gear. Communicate to
The in-wheel motor drive device according to claim 1, wherein the casing rotatably supports the intermediate gear.

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