JP2018043574A - In-wheel motor drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new and useful brake caliper support structure related to an in-wheel motor including a brake caliper.SOLUTION: An in-wheel motor drive device includes: a wheel hub bearing part (11); a motor part which drives a wheel (W); a speed reduction part which reduces a speed of rotation of the motor part to transmit the rotation to an outer ring; and a brake caliper (81) which puts a brake on the wheel. An inner fixing member (13) includes: a fixed shaft (15) which supports rolling elements (14) at one end side in an axis (O) direction; and a caliper support part (15s) extending from the other axial end side of the fixed shaft in an outer diameter direction of the wheel hub bearing part. A casing (43a) houses one axial end side area of the fixed shaft, and the brake caliper is disposed at the outside of the casing and supported by the caliper support part.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an in-wheel motor drive device coupled to a wheel, and more particularly to a brake caliper support structure for braking a wheel.

  Among the in-wheel motors that are arranged in the inner space of the wheel and drive the wheel, a structure is known in which a brake disc is connected to the wheel, a brake caliper is attached to the in-wheel motor, and the brake caliper is used to brake the brake disc. It has been. As such an in-wheel motor, conventionally, for example, there is a technique described in JP-A-2015-90170 (Patent Document 1). In the in-wheel motor described in Patent Document 1, a pair of brackets are bolted to a cylindrical wall of an in-wheel motor casing, and one brake caliper is supported by these brackets.

  The in-wheel motor occupies most of the inner space of the wheel, and the bracket of Patent Document 1 is arranged using an annular gap between the rim inner peripheral surface of the wheel wheel and the casing cylindrical wall outer peripheral surface. Therefore, it is a rational support structure using a narrow space.

JP-A-2015-90170

  However, the present inventor has found that there is a further improvement in the caliper support structure as described above. That is, the braking force of the brake is input from the brake caliper to the casing cylindrical wall, which causes the in-wheel motor casing to be deformed. The in-wheel motor casing supports rotating parts such as gears in the inside thereof. Further, in order to meet the demand for lightening the unsprung load as seen from the wheel suspension device, the in-wheel motor casing may be made thin or made of a light metal mainly composed of aluminum or the like. Then, misalignment (misalignment) of the axial positions of the rotating parts occurs inside the in-wheel motor casing, and there are concerns about noise and vibration, and deterioration of the durability of the in-wheel motor.

  In view of the above circumstances, the present invention relates to an in-wheel motor provided with a brake caliper, and an object thereof is to provide a new and useful brake caliper support structure.

  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 in a center hole 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 having a moving body, a motor that drives the outer ring, a speed reduction unit that reduces the rotation of the motor and transmits the rotation to the outer ring, and a brake caliper that brakes the wheel. The fixed shaft that supports the rolling element on one end side, and a caliper support portion that extends from the other end side in the axial direction of the fixed shaft in the outer diameter direction of the wheel hub bearing portion, and the casing that forms the outline of the speed reduction portion is the axial direction of the fixed shaft The one end side region is accommodated, and the brake caliper is disposed outside the casing and supported by the caliper support portion.

  According to the present invention, the brake caliper is disposed outside the casing of the in-wheel motor drive device and supported by the caliper support portion that is coupled to the inner fixing member, so that the brake caliper is supported by the casing of the in-wheel motor drive device. There is nothing to do. Therefore, the braking force input from the wheel side to the brake caliper during braking of the wheel is not transmitted to the casing, and it is not necessary to increase the rigidity by increasing the thickness of the casing, thereby reducing the weight of the casing. The brake caliper has a friction material, and brakes the wheel by pressing the friction material against a rotating member on the wheel side. The structure of the brake caliper is not particularly limited, such as a hydraulic type or an electric type. The structure of the wheel-side rotating member that is braked by the brake caliper is not particularly limited. The wheel-side rotating member is a friction member such as a brake rotor or a brake disk, for example.

  As one embodiment of the present invention, a bracket further disposed outside the casing and extending from the tip of the caliper support portion to one end in the axial direction of the wheel hub bearing portion, and the brake caliper is attached and fixed to the bracket. According to this embodiment, the brake caliper can be disposed in the inner space region of the wheel close to one end in the axial direction of the in-wheel motor drive device, that is, outside in the vehicle width direction. The bracket and the caliper support may be separate members or may be integrally coupled.

  The caliper support may be disposed inside the casing or may be disposed outside. The fixed shaft and the caliper support portion may be separate members or may be integrally coupled. As another embodiment of the present invention, a casing accommodates a fixed shaft and a caliper support portion, and a through hole is formed in a portion of the casing facing the tip of the caliper support portion, and an intermediate member is disposed in the through hole. The intermediate member is interposed between the bracket and the caliper support. According to this embodiment, even when the caliper support portion is disposed inside the casing, the braking force input from the wheel side to the brake caliper during braking of the wheel is not transmitted to the casing, and the casing is thickened. Thus, it is not necessary to increase the rigidity, and the weight of the casing can be reduced.

  As a preferred embodiment of the present invention, the intermediate member is a cylindrical body having a center hole, a female screw hole is formed at the tip of the caliper support portion, and the tip of the bracket and the caliper support portion penetrates the center hole of the intermediate member. Then, they are connected and fixed to each other by a bolt that is screwed into the female screw hole of the caliper support portion. According to such an embodiment, inspection of the brake caliper and repair and replacement of the bracket are facilitated. In addition, it is good to form the hole thru | or notch for a volt | bolt to penetrate in a bracket.

  Although the number of brackets is not particularly limited, as one embodiment of the present invention, two brackets form a pair, and are arranged apart from each other in the circumferential direction around the axis of the wheel hub bearing portion. Support each one. According to this embodiment, the brake caliper can be stably supported, and the support rigidity is improved.

  Thus, according to the present invention, the braking force input from the wheel side to the brake caliper during braking of the wheel is not transmitted to the casing of the in-wheel motor drive device, and there is no need to increase the rigidity by increasing the thickness of the casing. Therefore, the casing can be reduced in weight, which contributes to the reduction in the weight of the in-wheel motor drive device.

It is a perspective view which shows the in-wheel motor drive device which becomes one Embodiment of this invention. It is a front view which shows the same embodiment. It is a cross-sectional view which shows the inside of the same embodiment. It is an expanded sectional view showing the embodiment. It is a longitudinal cross-sectional view which shows a brake caliper. It is a longitudinal cross-sectional view which shows the in-wheel motor drive device which becomes other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an in-wheel motor drive apparatus according to an embodiment of the present invention. FIG. 2 is a front view showing the embodiment, and shows a state viewed from the outside in the vehicle width direction (also referred to as the outboard side) of the electric vehicle. FIG. 3 is a cross-sectional view showing the inside of the embodiment. FIG. 4 is a developed cross-sectional view showing the embodiment, and 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 illustrated in FIG. It is the expansion | deployment plane connected in this order.

  The in-wheel motor drive device 10 includes a wheel hub bearing portion 11 shown in FIG. 3, a motor portion 21, and a speed reduction portion 31 that decelerates the rotation of the motor portion 21 and transmits it to the wheel hub bearing portion 11. Arranged in a wheel housing (not shown). 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 region of the wheel wheel W represented by the phantom line in FIG. 3 and is connected to the center of the wheel wheel W to drive the wheel wheel W of the wheel.

  Each in-wheel motor drive device 10 is connected to the vehicle body of the electric vehicle via the suspension device 70. The suspension device 70 includes a plurality of arm members, for example, a combination of a lower arm and an upper strut, a combination of a lower arm and an upper arm, a trailing arm, or another arm member. In the figure, a lower arm 71 as a suspension device is shown. The lower arm 71 extends in the vehicle width direction and is disposed below the axis O. 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.

  As shown in FIGS. 3 and 4, the motor unit 21 and the speed reduction unit 31 are not arranged coaxially with the axis O of the wheel hub bearing 11, but are offset from the axis O of the wheel hub bearing 11. The The in-wheel motor drive device 10 is attached to both the left and right sides of the vehicle body in the vehicle width direction, and is disposed in the inner space of the wheel wheel W. That is, the in-wheel motor drive device 10 is disposed in a lower part, a part disposed in the forward direction of the electric vehicle, a part disposed in the rear direction of the electric vehicle, a part disposed in the upper direction, as will be described in detail later. Part.

  As shown in FIG. 4, the wheel hub bearing portion 11 includes an outer ring 12 as a wheel hub coupled to the wheel W, an inner fixing member 13 disposed in the 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, 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 penetrates the main body casing 43 that forms the outline of the wheel hub bearing portion 11 and the speed reduction portion 31. The main body casing 43 is a casing that forms an outline of the in-wheel motor drive device 10. Specifically, as shown in FIG. 4, the main body casing 43 includes most of the outer end surface in the vehicle width direction of the in-wheel motor drive device 10 (hereinafter also referred to as one end surface in the axis O direction or the front surface). As shown, it extends over the entire circumference of the in-wheel motor drive device 10 and further includes a part of the inner end surface in the vehicle width direction of the in-wheel motor drive device 10 (hereinafter also referred to as the other end surface in the axis O direction or the back surface). The inner fixing member 13 and the main body casing 43 are separate members.

  As shown in FIG. 4, the distal end portion 15 e of the fixed shaft 15 passes through an opening 43 p formed in the front portion 43 f of the main body casing 43 and protrudes outward in the vehicle width direction from the front portion 43 f. The root portion 15r of the fixed shaft 15 passes through an opening 43q formed in the back surface portion 43b from the inner side in the vehicle width direction than the back surface portion 43b of the main body casing 43. 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 of the fixed shaft 15. As shown in FIG. 1, the hub carrier 18 is connected to the suspension device 70 and the tie rod 74 outside the main body casing 43. For example, the hub carrier 18 extends downward from the axis O and is connected to the lower arm 71, another arm 18 c extends upward from the axis O and connected to the strut 76, and extends from the axis O to the rear of the vehicle. And a further arm portion 18 d connected to the tie rod 74.

  The lower arm 71 extends in the vehicle width direction and can swing in the vertical direction with a vehicle width direction inner end 71a as a base end and a vehicle width direction outer end 71b connected to the arm portion 18 via a ball joint 72 as a free end. It is. The strut 76 has a built-in shock absorber and can be expanded and contracted in the vertical direction. The suspension device 70 of this embodiment is a strut suspension device. As shown in FIG. 2, a straight line extending in the vertical direction through the upper end of the strut 76 and the ball joint 72 constitutes a turning axis K. The tie rod 74 is displaced in the vehicle width direction by a steering device (not shown). Then, the in-wheel motor drive device 10 steers around the turning axis K together with the wheels.

  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. 4 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 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 radial protrusion that protrudes toward the outer diameter side with an interval in the circumferential direction.

  The wheel W is well known and has a spoke part Ws extending radially from the axis O and a rim part Wr extending in the axis O direction from the radially outer edge of the spoke part Ws. The outer periphery of the wheel W, that is, the rim portion Wr and a tire (not shown) are fitted. The tire and the wheel W constitute a wheel.

  As shown in FIG. 4, the motor unit 21 includes a motor rotation shaft 22, a rotor 23, a stator 24, and a motor casing 25 c, and is 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.

  The stator 24 is connected to a power line (not shown) extending from the vehicle body side. The motor unit 21 is supplied with electric power from the vehicle body side through a power line and performs a power running operation, or performs a regenerative operation in which the rotation of the outer ring 12 is converted into electric power and supplied to the vehicle body side through the power line.

  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 positions of the motor unit 21 excluding the tip of the motor rotating shaft 22 do not overlap with the axial positions of the inner fixing member 13 as shown in FIG. The cylindrical motor casing 25 c is coupled to the back surface portion 43 b of the main body casing 43 at one end in the axis M direction. The internal space of the motor casing 25c and the internal space of the main body casing 43 are partitioned by a back surface portion 43b. A through hole is formed along the axis M at the center of the partition wall. The end 22e of the motor rotating shaft 22 is passed through the through hole. The cylindrical motor casing 25c 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 25c and the motor casing cover 25v via the rolling bearings 27 and 28. The motor unit 21 drives the outer ring 12 (that is, the wheel) and the pump shaft 51 (FIG. 3).

  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 end 22 e of the motor rotation shaft 22, and extends along the axis M of the motor unit 21. The end 22 e is received in the center hole at the other end of the input shaft 32 in the axis M direction, and the input shaft 32 is coaxially coupled to 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 larger diameter than the cylindrical portion of the outer ring 12, and extends along the axis O of the wheel hub bearing portion 11. The other end in the axis O direction of the outer ring 12 is received in a central hole at one end of the output shaft 41 in the axis O direction, and the output shaft 41 is coaxially coupled to the outer ring 12 by spline fitting or the like. 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. Rolling bearings 44 and 46 are disposed at both ends of the output shaft 41 in the direction of the axis O.

  The rolling bearing 44 is disposed on one side in the axis O direction with respect to the output gear 40, and is provided between the outer peripheral surface of the output shaft 41 and the inner peripheral surface of the opening 43p. Further, the rolling bearing 44 is disposed on the outer diameter side of the outer ring 12 so as to overlap the position of the outer ring 12 in the axis O direction.

  The rolling bearing 46 is disposed on the other side in the axis O direction than the outer ring 12, and is provided between the inner peripheral surface of the output shaft 41 and the outer peripheral surface of the fixed shaft 15. Further, the rolling bearing 46 is arranged on the inner diameter side of the output gear 40 so as to overlap with the position in the axis O direction of the output gear 40.

  With respect to the position in the axis O direction, the rolling bearing 44 is disposed so as to overlap the other region of the outer ring 12 in the axis O direction, but the rolling bearing 46 is disposed on the other side in the axis O direction relative to the outer ring 12 and does not overlap the outer ring 12. The rolling bearing 46 is disposed on the inner diameter side of the teeth of the output gear 40, and the position of the rolling bearing 46 in the axis O direction overlaps the position of the output gear 40 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. 3, 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 a modification (not shown), the axis M of the input shaft 32, the axis Nf of the intermediate shaft 35, the axis Nl of the intermediate shaft 38, and the axis O of the output shaft 41 may be arranged in this order in the vehicle longitudinal direction. This order is also the order in which the driving force is transmitted.

  The vertical position of each axis will be described. The input shaft 32 is arranged such that the vertical position of the input shaft 32 overlaps with the vertical position 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 38 is disposed above the intermediate shaft 35 as shown in FIG. As a modification, the intermediate shaft 35 may be disposed above the intermediate shaft 38. 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 region of the intermediate shaft 35 in the direction of the axis Nf as shown in FIG. Both end portions of the intermediate shaft 35 are supported by a wall-shaped 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 region of the intermediate shaft 38 in the direction of the axis Nl. Both end portions of the intermediate shaft 38 are supported by a wall-shaped main body casing 43 via rolling bearings 48a and 48b.

  The main body casing 43 forms an outer shape of the speed reduction portion 31 and the wheel hub bearing portion 11, is formed in a cylindrical shape, and surrounds the axes O, Nf, Nl, and M as shown in FIG. Further, the main casing 43 is accommodated in the inner space of the wheel W as shown in FIG. The inner space of the wheel W is defined by an inner peripheral surface of the rim portion Wr and a 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. 3, main body casing 43 has a portion 43 c below axis O and a position away from axis O of output gear 40 in the vehicle front-rear direction, specifically, below axis M of input gear 33 and downward. And a protruding portion. This protruding portion forms an oil tank 47 and is located below the portion 43c directly below.

  The main body casing 43 has a cylindrical shape as shown in FIG. 3, and as shown in FIG. 4, 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, and the intermediate shaft 38 The gear 39, the output gear 40, the output shaft 41, and the central portion in the axis O direction of the wheel hub bearing portion 11 are accommodated. Lubricating oil is enclosed in the main body casing 43, and the speed reducing portion 31 is lubricated. 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 includes a cylindrical portion 43a that includes a lower portion 43c and an oil tank 47 and surrounds a group of gears 33, 34, 36, 37, 39, and 40, and a speed reduction as shown in FIG. It has a substantially flat front portion 43f that covers one side in the axial direction of the cylindrical portion of the portion 31, and a substantially flat back portion 43b that covers the other side in the axial direction of the cylindrical portion of the speed reducing portion 31. The back surface portion 43b is coupled to the motor casing 25c. Further, the back surface portion 43 b is coupled to the fixed shaft 15.

  An opening 43p through which the outer ring 12 passes is formed in the front portion 43f. A sealing material 43 s is provided in the annular gap between the opening 43 p and the output shaft 41. The sealing material 43 s is arranged on one side in the axis O direction relative to the rolling bearing 44 to seal the annular gap. 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. In this way, 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 caused by the meshing of the small gear on the driving side and the large gear on the driven side. Is decelerated by the output shaft 41. Thereby, the deceleration part 31 ensures a sufficient reduction ratio. Of the plurality of intermediate gears 34, 36, 37, 39, the intermediate gear 34 is a first intermediate gear positioned on the input side of the drive transmission path. Of the plurality of intermediate gears 34, 36, 37, 39, the intermediate gear 39 is a final intermediate gear positioned on the output side of the drive transmission path.

  As shown in FIG. 3, 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 serving as a wheel hub, and a space for arranging the oil tank 47 can be secured below the outer ring 12, or the suspension device can be disposed directly below the outer ring 12. A space for placing the ball joint 72 can be secured. Therefore, a turning axis that passes through the ball joint 72 and extends in the vertical direction can be provided so as to intersect the wheel hub bearing portion 11, and the wheel wheel W and the in-wheel motor drive device 10 can be suitably turned around the turning axis. It can be steered.

  The main body casing 43 further accommodates a pump shaft 51 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 rotatably supported on both ends of the axis P direction via a rolling bearing (not shown), and is coupled to the pump gear 53 coaxially. The pump gear 53 is an external gear and is also a helical gear and meshes with the output gear 40. The output gear 40 drives the pump shaft 51.

  As shown in FIG. 3, 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 not shown in FIG. 3 is, for example, a cycloid pump disposed 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 vehicle with respect to the output shaft 41. 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.

  When the pump shaft 51 is driven by the output gear 40, the oil pump sucks the lubricating oil in the oil tank 47, pumps the sucked lubricating oil upward, and inputs the input gear 33 and the intermediate gears 34, 36, 37, 39. Then, lubricating oil is supplied to these rotating parts from above the output gear 40 and the rolling bearings 42a, 42b, 45a, 45b, 44, 46, 48a, 48b. Further, the lubricating oil pumped upward is injected into the motor unit 21 and supplied to the rotor 23, the stator 24, and the rolling bearings 27 and 28. Thereby, the motor part 21 and the deceleration part 31 are lubricated and cooled.

  A disc brake mechanism is attached to the in-wheel motor drive device 10 of the present embodiment. As shown in FIG. 1, the disc brake mechanism includes a brake disc BD that rotates integrally with a wheel and a non-rotating brake caliper 81.

  As shown in FIG. 4, the brake disc BD is disposed coaxially with the axis O, and is connected and fixed to the flange portion 12 f of the outer ring 12. As shown in FIG. 2, the brake caliper 81 is disposed along the outer edge of the brake disc BD. The brake caliper 81 is driven by hydraulic pressure, or incorporates an electric motor for driving, and brakes by sandwiching the brake disc BD.

  FIG. 5 is a longitudinal sectional view schematically showing the cut surface by cutting the in-wheel motor drive device 10 along a plane that includes the axis O and intersects the brake caliper 81. In FIG. 5, instead of the above-described rolling bearing 46, a rolling bearing 46 'as a modified example is shown. An annular peripheral wall 43r is erected on the inner wall surface of the back surface portion 43b of the main body casing 43. The rolling bearing 46 ′ is provided between the outer peripheral surface at the other end of the output shaft 41 in the axis O direction and the inner peripheral surface of the peripheral wall 43 r. In any case, like the rolling bearing 46 shown in FIG. 4, the rolling bearing 46 ′ shown in FIG. 5 is arranged coaxially with the axis O, and rotatably supports the output shaft 41.

  The inner fixing member 13 includes a fixed shaft 15 that supports the rolling element 14 at one end side in the axis O direction. The fixed shaft 15 includes a caliper support portion 15 s extending in the outer diameter direction of the wheel hub bearing portion 11 from a root portion 15 r on the other end side of the fixed shaft 15 in the axis O direction. A main body casing 43 that forms an outline of the speed reduction portion 31 accommodates an intermediate region of the fixed shaft 15 excluding the tip portion 15e, the root portion 15r, and the caliper support portion 15s of the fixed shaft 15. The root portion 15r and the caliper support portion 15s are disposed on the inner side in the vehicle width direction than the back surface portion 43b. The brake caliper 81 is disposed outside the main body casing 43 and is supported by the caliper support portion 15s.

  Specifically, the bracket 82 is disposed outside the main body casing 43. The bracket 82 is separated from the main body casing 43 and extends from the tip of the caliper support portion 15 s to one end side in the axis O direction of the wheel hub bearing portion 11. The brake caliper 81 is separated from the main body casing 43 and is fixedly attached to one end of the bracket 82 in the axis O direction by a connector such as a bolt 83a. The other end of the bracket 82 in the direction of the axis O is attached and fixed to the tip of the caliper support 15s by a connector such as a bolt 83b. As shown in FIG. 2, the brake caliper 81 includes a main body portion that includes a piston mechanism and extends in an arc shape, and connecting seat portions 81 b and 81 c that are formed at both ends of the main body portion. The brake caliper 81 is disposed above the in-wheel motor drive device 10 and behind the vehicle. The connecting seat portion 81 b is disposed on the rear side of the in-wheel motor drive device 10. The connecting seat portion 81 c is disposed above the in-wheel motor driving device 10. Each connection seat part 81b, 81c is formed with a female screw hole to be screwed with the bolt 83a.

  In the embodiment shown in FIG. 5, one end region in the axis O direction of the fixed shaft 15 is disposed inside the main body casing 43, whereas the caliper support portion 15 s provided at the other end in the axis O direction of the fixed shaft 15 is the main body casing. 43 is arranged outside. The caliper support portion 15s is adjacent to the outer surface of the back surface portion 43b, and the tip of the caliper support portion 15s protrudes beyond the cylindrical portion 43a to the outer diameter side.

  In the embodiment shown in FIG. 5, one end in the axis O direction of the bracket 82 extending in the vehicle width direction is located on the inner side in the vehicle width direction from the front portion 43 f of the main body casing 43, and the other end in the axis O direction of the bracket 82 is the main body. It is located inside the vehicle width direction beyond the back surface portion 43b of the casing 43. In addition, as a modified example (not shown), one end of the bracket 82 in the axis O direction may be located on the outer side in the vehicle width direction beyond the front portion 43 f of the main body casing 43.

  According to the above-described embodiment, the brake caliper 81 is disposed outside the main body casing 43 and supported by the caliper support portion 15 s that is coupled to the inner fixing member 13, so that it is not supported by the main body casing 43. . Therefore, the braking force input from the brake disc BD to the brake caliper 81 during braking of the wheels is not transmitted to the main body casing 43, and it is not necessary to increase the rigidity by increasing the thickness of the main body casing 43, thereby reducing the weight of the main body casing 43. Can be planned.

  Moreover, according to the above-described embodiment, the bracket 82 is further provided outside the main body casing 43 and extends from the tip of the caliper support portion 15s to one end side in the axis O direction of the wheel hub bearing portion 11, and the brake caliper 81 includes the bracket caliper 81. 82 is attached and fixed. As a result, the brake caliper 81 can be placed close to one end side in the axis O direction (outside in the vehicle width direction) of the in-wheel motor drive device 10 and disposed in the inner space of the wheel. Further, according to the above-described embodiment, the brake caliper 81 can be disposed on the outer side in the vehicle width direction than the wheel center of the wheel W (FIG. 4) by sufficiently increasing the overall length of the bracket 82. Note that the wheel motor center is a point on the axis O in FIG. 4 and the center of the rim Wr in the direction of the axis O.

  Further, according to the above-described embodiment, as shown in FIG. 1, two brackets 82 form a pair and are spaced apart in the circumferential direction around the axis O of the wheel hub bearing 11, and both ends of the brake caliper 81 are arranged. Since each part is supported, the brake caliper 81 can be supported stably.

  Next, an in-wheel motor drive device according to another embodiment of the present invention will be described. FIG. 6 is a longitudinal sectional view showing another embodiment of the present invention, in which the in-wheel motor drive device 10 is cut along a plane that includes the axis O and intersects the brake caliper 81, and schematically shows the cut surface. Constituent elements that are the same as those in the above-described embodiment will be given the same reference numerals, description thereof will be omitted, and different structures will be described below. In another embodiment, the entire fixed shaft 15 including the root portion 15 r and the caliper support portion 15 s is accommodated in the main body casing 43. Instead of passing the fixed shaft 15 through the opening 43q of the back surface portion 43b, the intermediate member 19 is arranged.

  The intermediate member has a cylindrical shape, and a bolt 20 is passed through the center hole of the intermediate member 19. A female screw hole to be screwed with the bolt 20 is formed in the root portion 15r. The hub carrier 18 disposed outside the main body casing 43 is formed with a through hole 18h through which the bolt 20 passes. The bolt 20 extends in parallel with the axis O, the head of the bolt 20 is set to the inner side in the vehicle width direction, the shaft portion is set to the outer side in the vehicle width direction, and passes through the hub carrier 18 and the intermediate member 19 on the inner side in the vehicle width direction. Screw into the 15r female screw hole. Thereby, the hub carrier 18 is connected and fixed to the inner fixing member 13 by a connecting tool such as a bolt 20.

  An annular sealing material 79c such as an O-ring is interposed between the inner peripheral surface of the opening 43q and the outer peripheral surface of the intermediate member 19. An annular seal material 79d such as an O-ring is interposed between the other end surface of the fixed shaft 15 in the axis O direction and one end surface of the intermediate member 19 in the axis O direction. Thereby, the opening 43q and the center hole of the intermediate member 19 are sealed, and the lubricating oil inside the main body casing 43 is prevented from leaking.

  A flange-shaped flange portion 19b is formed on the outer periphery of one end of the intermediate member 19 in the axis O direction. On the other hand, the inner circumference of one end of the opening 43q in the axis O direction is formed to have a larger diameter than the other end in the axis O direction and receives the flange portion 19b. Thus, the opening 43q and the intermediate member 19 are formed in the inlay and engage with each other. Thus, the intermediate member 19 is formed to have different outer diameters at one end side and the other end side of the cylindrical body, and is prevented from coming out from the back surface portion 43b.

  In order to reduce the weight of the in-wheel motor drive device 10, the main body casing 43, the motor casing 25c, and the motor casing cover 25v are made of light metal mainly composed of light metal such as aluminum. On the other hand, the intermediate member 19 is made of a hard metal having a larger elastic coefficient than that of a light metal, for example, steel. Thereby, the connection rigidity of the inner side fixing member 13 and the hub carrier 18 is ensured.

  A through hole 43d is formed in a portion of the cylindrical portion 43a of the main casing 43 that faces the tip of the caliper support portion 15s. An intermediate member 84 is disposed in the through hole 43d. The intermediate member 84 is configured in the same manner as the intermediate member 19 described above, is made of a metal that is harder than a light metal, and is provided with a collar portion 84b, thereby providing the above-described action. That is, the intermediate member 84 has a cylindrical shape, and the bolt 83b is passed therethrough. The steel intermediate member 84 is interposed between the bracket 82 and the caliper support 15s, and ensures the connection rigidity between the bracket 82 and the caliper support 15s. The intermediate member 84 has a large-diameter flange portion 84b on the inner side of the main body casing 43, and has a small diameter on the outer side of the main body casing 43. The large-diameter flange portion 84b engages with the cylindrical portion 43a. . Thus, the intermediate member 84 is formed to have different outer diameters at one end side and the other end side of the cylindrical body, and is prevented from coming out from the main body casing 43 to the outside.

  Between the inner peripheral surface of the through hole 43d and the outer peripheral surface of the intermediate member 84, an annular sealing material 85c such as an O-ring is disposed. An annular seal member 85d such as an O-ring is disposed between the intermediate member 84 and the caliper support portion 15s. The operation of these sealing materials 85c and 85d is the same as that of the sealing materials 79c and 79d described above.

  An oil pump 54 is disposed at the end of the pump shaft 51 in the direction of the axis P. Rolling bearings 52 a and 52 b are disposed between one end of the pump shaft 51 in the axis P direction and between the pump gear 53 and the oil pump 54. The rolling bearings 52a and 52b support the pump shaft 51 rotatably. When the pump gear 53 of the pump shaft 51 is driven by the output gear 40, the oil pump 54 sucks the lubricating oil in the oil tank 47 shown in FIG. 3 described above, pumps the sucked lubricating oil upward, and the input gear 33. Lubricating oil is supplied to these rotating parts from above the intermediate gears 34, 36, 37, 39, the output gear 40, and the rolling bearings 42a, 42b, 45a, 45b, 44, 46, 48a, 48b. Further, the lubricating oil pumped upward is injected into the motor unit 21 and supplied to the rotor 23, the stator 24, and the rolling bearings 27 and 28. Thereby, the motor part 21 and the deceleration part 31 are lubricated and cooled.

  According to the embodiment shown in FIG. 6, the main body casing 43 also accommodates the entire fixed shaft 15, that is, the caliper support portion 15 s of the fixed shaft 15. A through-hole 43d is formed in a portion of the main body casing 43 that faces the tip of the caliper support portion 15s. An intermediate member 84 is disposed in the through hole 43d, and the intermediate member 84 is interposed between the bracket 82 and the caliper support portion 15s. As a result, even when the caliper support portion 15s is disposed inside the main body casing 43, the braking force input from the brake disc BD to the brake caliper 81 during braking of the wheels is not transmitted to the main body casing 43, and the main body casing. There is no need to increase the thickness of 43 to increase the rigidity, and the weight of the main body casing 43 can be reduced.

  As shown in FIG. 6, the brake caliper 81 and the bracket 82 are disposed adjacent to the outer surface of the main body casing 43, but as a modification not shown, the brake caliper 81 and / or the bracket 82 are separated from the main body casing 43. You may arrange.

  Further, according to the embodiment shown in FIG. 6, the intermediate member 84 is a cylindrical body having a center hole, a female screw hole is formed at the tip of the caliper support portion 15 s, and a bolt 83 b passes through the bracket 82. A hole is formed, and the ends of the bracket 82 and the caliper support portion 15s are connected and fixed to each other by a bolt 83b that passes through the center hole of the intermediate member 84 and is screwed into the female screw hole of the caliper support portion 15s. This facilitates inspection of the brake caliper 81 and repair and replacement of the bracket 82.

  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 in-wheel motor drive, 11 wheel hub bearing,
12 outer ring, 13 inner fixing member, 14 rolling element,
15 fixed shaft, 15e tip, 15r root,
15s caliper support, 18 hub carrier,
18b, 18c, 18d arm part, 18h through-hole,
19 intermediate member, 19b collar part, 21 motor part,
22 motor rotating shaft, 25c motor casing,
25v motor casing cover, 31 reduction part,
32 input shafts, 35 and 38 intermediate shafts, 41 output shafts,
43 main body casing, 43a cylindrical part of main body casing,
43b The back part of the main casing,
43c Directly under the main casing, 43d through-hole,
43f Front portion of main casing, 47 oil tank,
70 suspension device, 79c, 79d sealing material,
81 Brake caliper, 82 Bracket,
83a, 83b connector (bolt), 84 intermediate member,
84b collar, 85c, 85d sealing material,
BD brake disc, M, Nf, Nl, O, P axis,
W Wheel wheel.

Claims (5)

An outer ring that rotates integrally with a wheel, an inner fixing member disposed in a center hole of the outer ring, a wheel hub bearing portion having a plurality of rolling elements disposed in an annular gap between the outer ring and the inner fixing member, and the outer ring A motor unit that drives the motor unit, a deceleration unit that decelerates the rotation of the motor unit and transmits it to the outer wheel, and a brake caliper that brakes the wheel,
The inner fixing member includes a fixed shaft that supports the rolling element on one end side in the axial direction, and a caliper support portion that extends in the outer diameter direction of the wheel hub bearing portion from the other end side in the axial direction of the fixed shaft.
A casing that forms an outline of the speed reduction part accommodates an axial direction one end side region of the fixed shaft,
The in-wheel motor drive device, wherein the brake caliper is disposed outside the casing and supported by the caliper support portion. A bracket that is arranged outside the casing and further extends from the tip of the caliper support portion to one end side in the axial direction of the wheel hub bearing portion;
The in-wheel motor drive device according to claim 1, wherein the brake caliper is attached and fixed to the bracket. The casing accommodates the fixed shaft and the caliper support;
A through hole is formed in a portion of the casing that faces the tip of the caliper support portion.
An intermediate member is disposed in the through hole,
The in-wheel motor drive device according to claim 2, wherein the intermediate member is interposed between the bracket and the caliper support portion. The intermediate member is a cylindrical body,
A female screw hole is formed at the tip of the caliper support,
4. The in-wheel motor drive device according to claim 3, wherein tips of the bracket and the caliper support portion are coupled and fixed to each other by a bolt that passes through a center hole of the intermediate member and is screwed into the female screw hole.   5. The bracket according to claim 2, wherein two brackets form a pair, are spaced apart from each other in the circumferential direction around the axis of the wheel hub bearing portion, and respectively support both ends of the brake caliper. In-wheel motor drive device.

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