JP6688134B2 - In-wheel motor drive - Google Patents

Description

  The present invention relates to an in-wheel motor drive device, and more particularly to an in-wheel motor drive device in which a pulsar ring for detecting wheel speed is mounted on a brake disc.

  In recent years, in order to improve safety, the number of vehicles equipped with ABS (anti-lock brake system) is increasing. In ABS, a rotation sensor (wheel speed sensor) that detects the rotation of a wheel is used. The detection signal of the rotation sensor is transmitted to a control device mounted on the vehicle body side, and the control device controls the brake mechanism such as adjusting the brake hydraulic pressure of the wheels. Such a rotation sensor is used not only for ABS but also for ESC (anti-skid device).

  Such a rotation sensor is provided so as to face a sensor target, that is, a pulsar ring, attached to a rotating portion that rotates integrally with a wheel.

  Reference 1 discloses a configuration in which a pulsar ring (tone ring) is arranged in the hat portion of a brake disc.

JP, 2013-152023, A

  To avoid interference between the in-wheel motor drive device and the inner wall of the wheel housing formed on the vehicle width direction outer side of the vehicle body without sacrificing the vehicle interior space, shorten the axial length of the in-wheel motor drive device. There is a need to. In addition, when the in-wheel motor drive device is mounted on the steered wheels, the axial length of the in-wheel motor drive device must be set longer than that when the in-wheel motor drive device is mounted on the steered wheels without sacrificing the steering angle. Need to be even shorter.

  Currently, many brake assemblies include a pulsar ring (tone ring) for detecting the rotation of the wheel with a rotation sensor. It can be said that the configuration in which the pulser ring is provided in the hat portion of the brake disc as in Patent Document 1 described above is advantageous in that it does not affect the axial length of the in-wheel motor drive device.

  However, since the pulsar ring shown in Patent Document 1 is composed of a flat plate-shaped member extending in the radial direction, in order to arrange such a pulsar ring in the hat part, the outer diameter of the hat part is increased. Must-have. Then, since the brake disc itself has a large diameter, there is a problem that the riding comfort and running performance of the vehicle are deteriorated due to an increase in unsprung weight.

  The present invention has been made to solve the above problems, and an object thereof is to arrange a rotation detection mechanism including a rotation sensor and a pulser ring without affecting the length in the axle direction of the device. An object of the present invention is to provide an in-wheel motor drive device that can be used and can reduce the diameter of a brake disc.

  An in-wheel motor drive device according to an aspect of the present invention has a brake disc attached to a drive wheel, a pulsar ring attached to a hat portion of a brake disc that is a rotating portion, and a rotation sensor for detecting rotation of the pulsar ring attached to a fixed portion. ing. In this in-wheel motor drive device, the pulsar ring includes a flange portion that extends in the radial direction and is attached to the hat portion, and a detected portion that bends from the flange portion and extends in the axle direction and that faces the rotation sensor. And

  In this in-wheel motor drive device, the pulsar ring mounted in the hat portion of the brake disc includes a mounting flange portion extending in the radial direction and a detected portion extending in the axle direction. Therefore, the rotation detection mechanism can be arranged without affecting the axial length of the in-wheel motor drive device, and the pulser ring can be attached to the brake disc without increasing the diameter of the brake disc. As a result, the unsprung weight can be reduced, and the riding comfort and running performance of the vehicle can be improved.

  Preferably, the rotation sensor is attached to the casing of the in-wheel motor drive device.

  Preferably, the detected portion is connected to the inner diameter side end portion of the flange portion. In this case, it is preferable that the pulsar ring further includes a contact portion that is connected to the outer diameter side end portion of the flange portion and that contacts the inner diameter surface of the hat portion.

  Preferably, the rotation sensor is held by a holding member fixed to the casing. In this case, it is preferable that the holding member has a position adjusting portion for adjusting the position of the rotation sensor at least in the radial direction.

  According to the present invention, the pulser ring mounted in the hat portion of the brake disc includes a mounting flange portion extending in the radial direction and a detected portion extending in the axle direction. Therefore, the rotation detection mechanism can be arranged without affecting the axial length of the in-wheel motor drive device, and the pulser ring can be attached to the brake disc without increasing the diameter of the brake disc. As a result, the unsprung weight can be reduced, and the riding comfort and running performance of the vehicle can be improved.

It is a figure showing typically the state which looked at the in-wheel motor drive concerning a preferred embodiment of the present invention, and its peripheral structure from the inside of the cross direction. In the embodiment of the present invention, it is a diagram schematically showing a structure arranged in a wheel housing of a vehicle body as viewed from the front of the vehicle. FIG. 3 is a diagram schematically showing the structure shown in FIG. 2 as viewed from above the vehicle. It is a figure which shows typically the state which looked at the basic composition part of the in-wheel motor drive device which concerns on embodiment of this invention from the vehicle width direction outer side. It is a cross-sectional view showing a basic configuration portion of the in-wheel motor drive device according to the embodiment of the present invention. It is a development sectional view showing a basic composition part of an in-wheel motor drive concerning an embodiment of the invention. FIG. 1 is a vertical cross-sectional view schematically showing a basic constituent part and a suspension device of an in-wheel motor drive device according to an embodiment of the present invention. In an embodiment of the present invention, it is a longitudinal cross-sectional view schematically showing a rotation detection mechanism provided in the in-wheel motor drive device. It is a front view of the pulsar ring in an embodiment of the invention. FIG. 3 is an external perspective view of a holding member that holds a rotation sensor in the embodiment of the present invention. FIG. 6 is a cross-sectional view of a holding member that holds a rotation sensor in the embodiment of the present invention. FIG. 7 is a cross-sectional view schematically showing that the position of the rotation sensor held by the holding member is adjustable in the embodiment of the present invention. It is a longitudinal cross-sectional view which shows typically the rotation detection mechanism in the modification 1 of embodiment of this invention. It is a front view of the pulsar ring in the modification 1 of an embodiment of the invention. It is a longitudinal cross-sectional view which shows typically the rotation detection mechanism in the modification 2 of embodiment of this invention. It is a front view of the pulsar ring in the modification 2 of an embodiment of the invention. It is a longitudinal cross-sectional view which shows typically the rotation detection mechanism in the modification 3 of embodiment of this invention. It is a front view of the pulser ring in the modification 3 of an embodiment of the invention.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference characters and description thereof will not be repeated.

(About basic configuration)
First, a basic configuration of an in-wheel motor drive device according to an embodiment of the present invention and a peripheral structure thereof will be described with reference to FIGS. 1 to 7. The in-wheel motor drive device is mounted on a passenger vehicle such as an electric vehicle or a hybrid vehicle.

  As shown in FIG. 2 and the like, a wheel W, an in-wheel motor drive device 10, and a suspension device 70 are arranged on the vehicle width direction outer side of a vehicle body 101 (only the vehicle width direction outer side portion of the vehicle body is shown in FIG. 2). It The wheel W, the in-wheel motor drive device 10, and the suspension device 70 are arranged symmetrically on both sides of the vehicle body 101 in the vehicle width direction, and constitute an electric vehicle.

  The tire T shown by a virtual line is fitted around the outer periphery of the wheel W. Wheel Wheel W and tire T constitute a wheel. The rim portion Wr of the wheel W defines the inner space of the wheel. The in-wheel motor drive device 10 is arranged in the inner space area. The in-wheel motor drive device 10 is connected to the wheel W to drive the wheel.

  The suspension device 70 is a strut type suspension device, and includes a lower arm 71 extending in the vehicle width direction and a strut 76 arranged above the lower arm 71 and extending in the up-down direction. The strut 76 is arranged on the inner side in the vehicle width direction of the wheel wheel W and the in-wheel motor drive device 10, the lower end of the strut 76 is coupled to the in-wheel motor drive device 10, and the upper end of the strut 76 is located above the wheel wheel W. It is connected to the vehicle body 101. The struts 76, the upper portion of the wheel W, and the upper portion of the in-wheel motor drive device 10 are housed in a wheel housing 102 formed outside the vehicle body 101 in the vehicle width direction.

  The strut 76 is a suspension member which has a shock absorber 77 built in the upper end region thereof and is capable of expanding and contracting in the vertical direction. A coil spring 78, which is schematically shown by an imaginary line, is arranged on the outer periphery of the shock absorber 77 to reduce the vertical axial force acting on the strut 76. A pair of coil spring seats 79b, 79c that hold the upper and lower ends of the coil spring 78 between them are provided at the upper end and the center of the strut 76. Inside the shock absorber 77, a damper for damping the axial force acting on the strut 76 is provided.

  The lower arm 71 is a suspension member arranged below the axis O of the in-wheel motor drive device 10, and includes a vehicle width direction outer end 72 and vehicle width direction inner ends 73d and 73f. The lower arm 71 is connected to the in-wheel motor drive device 10 via the ball joint 60 at the vehicle width direction outer end 72. The lower arm 71 is connected to a vehicle body-side member (not shown) at inner ends 73d and 73f in the vehicle width direction. The lower arm 71 is vertically swingable with the vehicle width direction inner ends 73d and 73f as base ends and the vehicle width direction outer end 72 as a free end. The member on the vehicle body side refers to a member attached to the vehicle body side as viewed from the members described. The straight line connecting the vehicle width direction outer end 72 and the upper end 76a of the strut 76 extends in the up-down direction to form the steering axis K. The steered axis K basically extends in the vertical direction, but may be slightly inclined in the vehicle width direction and / or the vehicle longitudinal direction. In the drawings, when the inner ends 73d and 73f in the vehicle width direction are not distinguished, the reference numeral 73 is simply attached.

  A tie rod 80 is arranged above the lower arm 71. The tie rod 80 extends in the vehicle width direction, and the vehicle width direction outer end of the tie rod 80 is rotatably connected to the in-wheel motor drive device 10. The inner end of the tie rod 80 in the vehicle width direction is connected to a steering device (not shown). The steering device moves the tie rod 80 back and forth in the vehicle width direction to steer the in-wheel motor drive device 10 and the wheel W around the steering axis K.

  The basic components of the in-wheel motor drive device 10 will be described with particular reference to FIGS. In addition, in FIG. 5, each gear inside the reduction unit is represented by a tip circle, and the individual teeth are omitted. Further, the cutting plane shown in FIG. 6 includes a plane including the axis M and the axis Nf shown in FIG. 5, a plane including the axis Nf and the axis Nl, and a plane including the axis Nl and the axis O in this order. It is a connected development plane. FIG. 7 is a vertical cross-sectional view showing the in-wheel motor drive device 10, which is shown together with the wheel W and the suspension device 70. In order to avoid complexity of the drawing, in FIG. 7, each gear inside the speed reducer is omitted.

  The in-wheel motor drive device 10 includes a wheel hub bearing portion 11 that is connected to the center of the wheel wheel W represented by a virtual line as shown in FIG. 6, a motor portion 21 that drives the wheel wheel W of the wheel, and a motor portion. Is provided in the wheel housing (not shown) of the electric vehicle, which includes a speed reducing unit 31 that reduces the rotation of the vehicle and transmits it to the wheel hub bearing 11. The motor portion 21 and the reduction gear portion 31 are not arranged coaxially with the axis O of the wheel hub bearing portion 11, but are arranged offset from the axis O of the wheel hub bearing portion 11 as shown in FIG. The in-wheel motor drive device 10 can drive an electric vehicle on a public road at a speed of 0 to 180 km / h.

  As shown in FIG. 6, the wheel hub bearing portion 11 includes an outer ring 12 as a wheel hub that is coupled to a 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. It has a plurality of rolling elements 14 arranged in the annular gap, and constitutes an axle. The inner fixing member 13 includes a non-rotating fixed shaft 15, a pair of inner races 16, a retaining nut 17, and a carrier 18. The fixed shaft 15 has a root portion 15r larger in diameter than the tip portion 15e. The inner race 16 is fitted on the outer periphery of the fixed shaft 15 between the root portion 15r and the tip portion 15e. The retaining nut 17 is screwed onto the tip portion 15e of the fixed shaft 15 to fix the inner race 16 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 outer shell of the reduction gear unit 31. The front end portion 15e of the fixed shaft 15 penetrates an opening 43p formed in the front surface portion 43f of the main body casing 43, and projects further outward than the front surface portion 43f in the vehicle width direction. The root portion 15r of the fixed shaft 15 penetrates the opening 43q formed in the back surface portion 43b from the inside in the vehicle width direction of the back surface portion 43b of the main body casing 43. The front portion 43f and the rear portion 43b are wall portions facing each other with a space in the axis O direction. The carrier 18 is attached and fixed to the root portion 15r. The carrier 18 is connected to the suspension device 70 and the tie rod 80 outside the main body casing 43.

  The rolling elements 14 are arranged in a plurality of rows separated from each other in the direction of the axis O. The outer peripheral surface of the inner race 16 on one side in the axis O direction constitutes the inner raceway surface of the rolling elements 14 in the first row, and faces the inner peripheral surface of the outer ring 12 on the one side in the axis O direction. The outer peripheral surface of the inner race 16 on the other side in the axis O direction constitutes the inner raceway surface of the rolling elements 14 in the second row, and faces the inner peripheral surface of the outer ring 12 on the other side in the axis O direction. In the following description, the vehicle width direction outer side (outboard side) is also referred to as one axial direction, and the vehicle width direction inner side (inboard side) is also referred to as the other axial direction. The left-right direction on the paper surface of FIG. 6 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 direction of the axis O. The flange portion 12f constitutes a coupling seat portion for coaxially coupling with the brake disc BD and the spoke portion Ws of the 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 modified example (not shown), the flange portion 12f may be a protruding portion that protrudes toward the outer diameter side at intervals in the circumferential direction.

  The in-wheel motor drive device 10 according to the present embodiment includes a brake disc BD as a component, and includes a rotation detection mechanism that detects the wheel speed by detecting the rotation of the brake disc BD. The rotation detection mechanism includes a pulser ring and a rotation sensor that detects the rotation thereof, but their illustration is omitted in FIGS. 6 and 7. The rotation detection mechanism will be described later in detail.

  As shown in FIG. 6, the motor unit 21 has a motor rotating shaft 22, a rotor 23, a stator 24, and a motor casing 25, and they are sequentially arranged in this order from the axis M of the motor unit 21 toward the outer diameter side. The motor casing 25 has a cylindrical shape, and an inner end portion of the motor casing 25 in the vehicle width direction is connected to the motor casing cover 25v. The motor casing 25 and the motor casing cover 25v, together with the main body casing 43, form a casing of the in-wheel motor drive device 10. The motor section 21 is an inner rotor / outer stator type radial gap motor, but may be another type. For example, although not shown, the motor unit 21 may be an axial gap motor.

  An axis M, which is the center of rotation of the motor rotating shaft 22 and the rotor 23, extends parallel to the axis O of the wheel hub bearing 11. That is, the motor portion 21 is arranged offset from the axis O of the wheel hub bearing portion 11. The axial position of most of the motor portion 21 excluding the tip end portion of the motor rotating shaft 22 does not overlap with the axial position of the inner fixing member 13, as shown in FIG. The motor casing 25 has a tubular shape, is joined to the back surface portion 43b of the main body casing 43 at one end in the axis M direction, and is sealed by a lid-shaped motor casing cover 25v at the other end in the axis M direction. Both ends of the motor rotating shaft 22 are rotatably supported by the motor casing 25 and the motor casing cover 25v via rolling bearings 27 and 28. The motor unit 21 drives the outer wheel 12 and the wheels.

  As shown in FIG. 1, a power line terminal box 25b is provided above the in-wheel motor drive device 10. The power line terminal box 25b is formed over the upper portion of the motor casing 25 (FIG. 6) and the upper portion of the motor casing cover 25v (FIG. 6), and has a plurality of power line connecting portions 91. The power line terminal box 25b of the present embodiment has three power line connecting portions 91 and receives three-phase AC power. One end of a power line 93 is connected to each power line connecting portion 91. The core wire of the power line 93 is connected to the conducting wire extending from the coil of the stator 24 inside the power line terminal box 25b.

  A signal line terminal box 25c is formed at the center of the motor casing cover 25v. The signal line terminal box 25c is separated from the power line terminal box 25b. The signal line terminal box 25c is arranged so as to intersect the axis M as shown in FIG. The signal line terminal box 25c houses the rotation angle sensor 84. The rotation angle sensor 84 is provided at the axial end portion of the motor rotation shaft 22 and detects the rotation angle of the motor rotation shaft 22. A signal line connecting portion 85 is provided in the signal line terminal box 25c. The signal line connecting portion 85 has a wall portion of the signal line terminal box 25c, a through hole penetrating the wall portion, and a female screw hole (not shown) provided in the wall portion adjacent to the through hole. The sleeve 86 and the signal line 87 are passed through the through hole. The sleeve 86 is a tubular body, and adheres to the outer periphery of the signal line 87 to protect the signal line 87 and seal the annular gap between the through hole and the signal line 87. On the outer peripheral surface of the sleeve 86, a tongue portion 86t protruding in the outer diameter direction of the sleeve is formed. Bolts (not shown in FIG. 6) are screwed into the female screw holes of the tongue portion 86t and the signal line connecting portion 85, whereby the sleeve 86 is attached and fixed to the signal line connecting portion 85.

  The signal line 87 includes a plurality of core wires made of a conductor and a covering portion of an insulator that covers the plurality of core wires so as to be bundled, and is bendable. One end of the signal line 87 is connected to the signal line connecting portion 85. Although not shown, the signal line 87 extends from one end to the vehicle body 101 (FIG. 2).

  Each power line connecting portion 91 is also configured similarly to the signal line connecting portion 85, and is provided in the wall portion of the power line terminal box 25b, the through hole penetrating the wall portion, and the wall portion adjacent to the through hole. Has a female screw hole (not shown). One end of the sleeve 92 and the power line 93 is passed through the through hole. The sleeve 92 and the power line 93 extend from the through hole of the power line connecting portion 91 to the vehicle body 101 side. The power line 93 is passed through the sleeve 92 and extends from the sleeve 92 to the vehicle body 101 side. Each of the sleeves 92 is a tubular body, and adheres to the outer periphery of the power line 93 to protect the power line 93. Further, each sleeve 92 is inserted and fixed in the through hole of the power line connecting portion 91 together with one end of the power line 93 to hold one end of the power line 93, and further to form an annular gap between the power line 93 and the through hole. Seal. In order to prevent the sleeve 92 from coming off, a tongue portion 92t protruding in the outer diameter direction of the sleeve is formed on the outer peripheral surface of the sleeve 92. The bolt 91b shown in FIG. 1 is screwed into the female screw holes of the tongue portion 92t and the power line connecting portion 91, whereby the sleeve 92 is attached and fixed to the power line connecting portion 91.

  The 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 tubular body having a larger diameter than the tip portion 22e of the motor rotating shaft 22, and extends along the axis M of the motor portion 21. The tip 22e is received in the center hole of the other end of the input shaft 32 in the direction of the axis M, 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 diameter smaller than that of the motor unit 21, and is coaxially coupled to the input shaft 32. Specifically, the input gear 33 is integrally formed on the outer periphery of the central portion of the input shaft 32 in the direction of the axis M.

  The output shaft 41 is a tubular 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 11. The other end of the outer ring 12 in the axis O direction is received in the center hole of the one end of the output shaft 41 in the axis O direction, and the output shaft 41 is coupled to the outer ring 12 coaxially. Rolling bearings 44 and 46 are arranged on the outer circumferences of both ends of the output shaft 41 in the direction of the axis O. One end of the output shaft 41 in the direction of the axis O is supported by the front portion 43f of the main body casing 43 via a rolling bearing 44. The other end of the output shaft 41 in the direction of the axis O is supported by the back surface portion 43b of the main body casing 43 via a rolling bearing 46. The output gear 40 is an external gear and is coaxially coupled to the output shaft 41. Specifically, the output gear 40 is integrally formed on the outer periphery of the output shaft 41 at the other end in the direction of the axis O.

  The two intermediate shafts 35 and 38 extend parallel to the input shaft 32 and the output shaft 41. That is, the 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. It extends, in other words, extends in the vehicle width direction.

  The position of each axis in the vehicle front-rear direction will be described. As shown in FIG. 5, the axis M of the input shaft 32 is arranged in front of the axis O of the output shaft 41 in the vehicle. The axis Nf of the intermediate shaft 35 is arranged 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 axis O of the output shaft 41 in the vehicle and behind the axis M of the input shaft 32 in the vehicle. 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 front-rear direction. This order is also the order of transmitting the driving force.

  The vertical position of each shaft will be described. The axis M of the input shaft 32 is arranged above the axis O of the output shaft 41. The axis Nf of the intermediate shaft 35 is arranged above the axis M of the input shaft 32. The axis Nl of the intermediate shaft 38 is arranged above the axis Nf of the intermediate shaft 35. The plurality of intermediate shafts 35 and 38 need only be arranged above the input shaft 32 and the output shaft 41, and as a modification not shown, the intermediate shaft 35 may be arranged above the intermediate shaft 38. Alternatively, as a modified example not shown, the output shaft 41 may be arranged above the input shaft 32.

  The intermediate gear 34 and the intermediate gear 36 are external gears, and are coaxially coupled to the central portion of the intermediate shaft 35 in the direction of the axis Nf as shown in FIG. Both ends of the intermediate shaft 35 are supported by the main body casing 43 via rolling bearings 45a and 45b. The intermediate gear 37 and the intermediate gear 39 are external gears, and are coaxially coupled to the central portion of the intermediate shaft 38 in the direction of the axis Nl. Both ends of the intermediate shaft 38 are supported by the main body casing 43 via rolling bearings 48a and 48b.

  The main body casing 43 forms an outer shell of the speed reducing portion 31 and the wheel hub bearing portion 11, is formed in a tubular shape, and surrounds the axes O, Nf, Nl, and M as shown in FIG. Further, the main body casing 43 is housed in the inner space area of the wheel W as shown in FIG. 7. The inner empty area of the wheel W is defined by the inner peripheral surface of the rim portion Wr and the spoke portion Ws that is connected to one end of the rim portion Wr in the direction of the axis O. Then, one region in the axial direction of the wheel hub bearing portion 11, the speed reducing portion 31, and the motor portion 21 is housed in the inner space of the wheel W. Further, the other axial region of the motor portion 21 protrudes from the wheel W to the other axial direction. Thus, the wheel W accommodates most of the in-wheel motor drive device 10.

  With reference to FIG. 5, the main body casing 43 is located below the portion 43c directly below the axis O and at a position away from the axis O of the output gear 40 in the vehicle front-rear direction, specifically, directly below the axis M of the input gear 33. And a protruding portion. This protruding portion forms the oil tank 47 and is located below the portion directly below the portion 43c.

  7, the lower end portion 18b of the carrier 18 and the vehicle width direction outer end 72 of the lower arm 71 are arranged immediately below the lower portion 43c, and the vehicle width direction outer end 72 and the lower end portion 18b of the lower arm 71 are arranged. The ball joint 60 is connected so as to be freely directional. As shown in FIG. 5, when viewed in the direction of the axis O, the oil tank 47 is partitioned by a substantially vertical rear side wall portion 43t and an inclined front side wall portion 43u, and has a triangular shape that tapers downward. The rear side wall portion 43t faces the ball joint 60 (FIG. 7) in the vehicle front-rear direction at a distance. The front side wall portion 43u faces the front and lower portions of the rim portion Wr (FIG. 7).

  The ball joint 60 includes a ball stud 61 and a socket 62 as shown in FIG. 7. The ball stud 61 extends in the vertical direction and has a ball portion 61b formed at the upper end and a stud portion 61s formed at the lower end. The socket 62 is provided in the carrier 18 and slidably accommodates the ball portion 61b. The stud portion 61s vertically penetrates the vehicle width direction outer end 72 of the lower arm 71. A male screw is formed on the outer periphery of the lower end of the stud portion 61s, and the nut 72n is screwed from below to attach and fix the stud portion 61s to the lower arm 71. As shown in FIG. 1, the ball joint 60 is located above the lower end of the oil tank 47. The ball joint 60 and the oil tank 47 are arranged in the inner space of the wheel W, the ball joint 60 is arranged immediately below the axis O, and the oil tank 47 is arranged apart from the ball joint 60 in the vehicle front-rear direction. Further, the ball joint 60 is arranged outside the rear portion 43b in the vehicle width direction as shown in FIG. The steered axis K passes through the ball center of the ball portion 61b and extends in the vertical direction, and intersects the fixed shaft 15 and the ground contact surface R of the tire T. The upper end of the carrier 18 is attached and fixed to the lower end of the strut 76.

  The main body casing 43 has a tubular shape, and as shown in FIG. 6, 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, the output shaft 41, and the central portion of the wheel hub bearing portion 11 in the direction of the axis O. Lubricating oil is enclosed inside 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. 5, the main body casing 43 includes a tubular portion including the lower portion 43c and the oil tank 47, and a generally flat front portion that covers one axial side of the tubular portion of the speed reducer 31 as shown in FIG. 43 f and a substantially flat back surface portion 43 b that covers the other axial side of the tubular portion of the speed reduction portion 31. The back surface portion 43b is coupled to the motor casing 25. Further, the back surface portion 43b is coupled to the fixed shaft 15.

  An opening 43p through which the outer ring 12 penetrates is formed in the front portion 43f. The opening 43p is provided with a sealing material 43s that seals an annular gap with the output shaft 41. Therefore, the outer ring 12, which is a rotating body, is housed in the main body casing 43 except for one end in the axis O direction. A seal member 43v is arranged on the inner peripheral surface of the other end of the output shaft 41 in the direction of the axis O. The sealing material 43v seals the annular gap between the output shaft 41 and the back surface portion 43b.

  The small-diameter input gear 33 and the large-diameter intermediate gear 34 are arranged on the other side in the axial direction of the reduction unit 31 (motor unit 21 side) and mesh with each other. The small-diameter intermediate gear 36 and the large-diameter intermediate gear 37 are arranged on one axial side (the flange 12f side) of the reduction gear 31 and mesh with each other. The small-diameter intermediate gear 39 and the large-diameter output gear 40 are arranged on the other side in the axial direction of the speed reducer 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 from the input gear 33 to the output gear 40 via the plurality of intermediate gears 34, 36, 37, 39. It constitutes a drive transmission path. The rotation of the input shaft 32 is reduced by the intermediate shaft 35, the rotation of the intermediate shaft 35 is reduced by the intermediate shaft 38, and the rotation of the intermediate shaft 38 is reduced by the output shaft 41 due to the meshing of the small-diameter gear and the large-diameter gear described above. To be done. As a result, the reduction gear unit 31 ensures a sufficient reduction gear ratio. Of the plurality of intermediate gears, the intermediate gear 34 is the first intermediate gear located on the input side of the drive transmission path. Of the plurality of intermediate gears, the intermediate gear 39 is the final intermediate gear located on the output side of the drive transmission path.

  As shown in FIG. 5, the output shaft 41, the intermediate shaft 38, and the input shaft 32 are arranged in this order at intervals in the vehicle front-rear direction. Further, the intermediate shaft 35 and the intermediate shaft 38 are arranged above the input shaft 32 and the output shaft 41. According to such an embodiment, the intermediate shaft can be arranged above the outer ring 12 serving as a wheel hub to secure a space for arranging the oil tank 47 below the outer ring 12, or to directly under the outer ring 12 a ball joint 60 (see FIG. It is possible to secure a space for receiving 7). Therefore, the steering axis K extending 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 steered around the steering axis K.

(About rotation detection mechanism)
Next, the rotation detection mechanism 50 in the present embodiment will be described with reference to FIGS. Note that the schematic cross-sectional view of FIG. 8 illustrates a part of the configuration of the reduction gear unit 31 in an expanded manner, but the structure is expanded in the direction opposite to the developed view illustrated in FIG. 6.

  The rotation detecting mechanism 50 includes a pulsar ring 51 attached to the brake disc BD, which is a rotating portion, and a rotation sensor 54, which is attached to a fixed portion and detects the rotation of the pulsar ring 51. The rotation detection mechanism 50 in this embodiment employs a passive method. Therefore, the pulser ring 51 is made of, for example, a magnetic material (thin steel plate), and the rotation sensor 54 is made of, for example, a pickup coil.

  As shown in FIG. 8, the brake disc BD has a brake ring 81 sandwiched between the brake pads 83, and a hat portion 82 provided so as to project outward from the inner diameter side end of the brake ring 81 in the vehicle width direction. There is. The hat portion 82 includes a bottom wall portion 82a extending in the radial direction and a cylindrical portion 82b connected to the bottom wall portion 82a and the brake ring 81. The pulsar ring 51 is attached to the hat portion 82 of the brake disc BD so that its center coincides with the axis O. The rotation sensor 54 is attached to the main body casing 43. More specifically, the rotation sensor 54 is attached to a portion of the main body casing 43 facing the hat portion 82 via a holding member (stay) 55. The mounting structure of the rotation sensor 54 using the holding member 55 will be described later.

  The pulsar ring 51 has a flange portion 52 extending in the radial direction and a detected portion 53 extending in the axle direction. The detected portion 53 is formed in a cylindrical shape, and the flange portion 52 is provided on the outer edge of the detected portion 53 in the axle direction. In this way, the pulsar ring 51 is bent such that the flange portion 52 and the detected portion 53 are substantially L-shaped. The flange portion 52 may be formed in a ring shape, or as shown in FIG. 9, a plurality of flange portions 52 (for example, four) may be provided at equal intervals along the circumferential direction.

  The bolt 111 is fixed to the bottom wall portion 82a of the hat portion 82 in advance, and the flange portion 52 is provided with a through hole 52a for inserting the bolt 111. The flange portion 52 is attached to the bottom wall portion 82 a of the hat portion 82 by the nut 112 screwed to the tip portion of the bolt 111. A flat head screw may be interposed between the flange portion 52 and the nut 112. The centering of the pulsar ring 51 is performed using a jig. Since the central cylindrical portion of the bottom wall portion 82a of the hat portion 82 of the brake disc BD fits with the outer ring 12 as the wheel hub, the whirling of the pulsar ring 51 fixed to the bottom wall portion 82a is prevented.

  As shown in FIG. 11, the detected portion 53 is bent from the flange portion 52 and extends in the axle direction. The detected part 53 is a part which faces the rotation sensor 54 and whose rotation is detected by the rotation sensor 54. The radial length of the flange portion 52 is preferably shorter than the axial length of the detected portion 53.

  In the detected part 53, for example, a plurality of through holes 53a are provided at a predetermined pitch along the circumferential direction. As a result, irregularities are repeatedly formed on the outer peripheral surface of the detected portion 53. In this case, when the brake disc BD rotates, the rotation sensor 54 outputs an electromotive force that changes according to the unevenness of the detected portion 53 of the pulser ring 51 as a voltage. The detection signal of the rotation sensor 54 is transmitted to the control device provided on the vehicle body side.

  Since the pulsar ring 51 is thus arranged inside the hat portion 82 of the brake disc BD, the rotation detection mechanism 50 can be mounted without increasing the length of the in-wheel motor drive device 10 in the axle direction. Therefore, interference between the in-wheel motor drive device 10 and the inner wall of the wheel housing 102 (FIG. 2) can be avoided. Further, the in-wheel motor drive device 10 can be arranged without sacrificing the turning angle.

  Here, in FIG. 8, an arrangement structure of the pulsar ring 151 in the comparative example is illustrated in a broken line frame. It should be noted that the structures within the broken line frame are illustrated as being bilaterally symmetrical with respect to the in-wheel motor drive device 10 in the present embodiment in order to facilitate comparison.

  Also in the comparative example, the pulser ring 151 is mounted inside the hat portion 182 of the brake disc 180. However, the pulsar ring 151 is composed of only a portion extending in the radial direction, and the pulsar ring 151 is fixed in a state in which the entire pulsar ring 151 is in contact with the bottom wall portion 182 a of the hat portion 182. In this case, the mounting portion 152 for mounting the pulser ring 151 to the hat portion 182 and the detected portion 153 are provided so as to be continuous in the radial direction.

  On the other hand, in the present embodiment, only the flange portion 52 is fixed to the bottom wall portion 82a of the hat portion 82 in a contact state. In this way, by making the shape of the pulsar ring 51 into a cylindrical shape with the flange portion 52, the outer diameter dimension of the pulsar ring 51 can be reduced. Therefore, the outer diameter dimension L1 of the hat portion 82 of the brake disc BD can be made smaller than the outer diameter dimension L10 of the hat portion 182 of the brake disc 180 in the comparative example. As a result, the outer diameter dimension of the brake disc BD itself can be made smaller than that of the brake disc 180 in the comparative example. In other words, the outer diameter dimension of the brake disc BD can be made the same as that when the pulsar ring is not mounted on the brake disc.

  It should be noted that it is desirable that the detected portion 53 is completely within the range of the hat portion 82 in the axle direction, but the detected portion is within a range that does not affect the axial length of the in-wheel motor drive device 10. A part of 53 may protrude from the hat portion 82 to the inner side in the vehicle width direction.

  Next, a mounting structure of the rotation sensor 54 using the holding member 55 will be described. 10 and 11 schematically show the outer appearance and cross section of the holding member 55. 8, 10, and 11, holding member 55 includes a mounting portion 56 extending in the radial direction, and a holding portion 57 extending from the upper end of mounting portion 56 toward the vehicle width direction outer side. The holding portion 57 is inclined so that the angle with the mounting portion 56 is an obtuse angle.

  The mounting portion 56 is provided with a through hole 56a through which the bolt 113 is inserted. The holding member 55 is fixed to the main body casing 43 by screwing the bolt 113 inserted into the through hole 56 a into the female screw hole formed in the wall portion of the main body casing 43.

  The holding portion 57 is provided with a through hole 57a into which the main body of the rotation sensor 54 is fitted, and a through hole 57b into which the bolt 114 that has passed through the fixed piece 54b of the rotation sensor 54 is inserted. A female screw (not shown) is formed on the inner wall of the through hole 57b. The bolt 114 is screwed into the through hole 57b with the fixing piece 54b of the rotation sensor 54 sandwiched between the head portion and the holding portion 57. As a result, the rotation sensor 54 is held by the holding member 55 with its posture and orientation fixed.

  Here, the holding member 55 is configured to be able to move the rotation sensor 54 at least in the radial direction in order to adjust the distance (air gap) between the detection surface 54a of the rotation sensor 54 and the detected portion 53. desirable. In the present embodiment, as shown in FIGS. 10 and 11, the through hole 56a of the mounting portion 56 is a long hole that is long in the radial direction.

  Therefore, as shown by the arrow A1 in FIG. 12, the radial position of the holding member 55 with respect to the main body casing 43 can be finely adjusted. As a result, the rotation sensor 54 held by the holding member 55 can be moved in the radial direction, and the distance D1 between the detection surface 54a of the rotation sensor 54 and the outer peripheral surface of the detected portion 53, that is, the air gap is finely adjusted. be able to.

  In this way, the long hole 56a provided in the holding member 55 functions as a position adjusting portion for adjusting the position of the rotation sensor 54 in the radial direction. By providing such a position adjusting portion, it is possible to tolerate a manufacturing error and an assembly error of other parts. As a result, it is possible to prevent the detection accuracy of the rotation sensor 54 from decreasing.

  In this embodiment, the position of the rotation sensor 54 can be adjusted in the radial direction for adjusting the air gap, but the position of the rotation sensor 54 may be adjusted in the axle direction. . That is, the holding member 55 may have a position adjusting portion for adjusting the position of the rotation sensor 54 in both the radial direction and the axle direction. As a result, the detection surface 54a of the rotation sensor 54 faces the reading portion (more preferably, the central position of the portion) having the through hole 53a in the entire width of the detected portion 53, so that the rotation sensor 54 has an axial direction. The position can be finely adjusted.

  In this case, for example, the through holes 57a and 57b provided in the holding portion 57 of the holding member 55 may be elongated holes that are long in the axle direction. However, in that case, it is desirable to separately provide a member for stabilizing the posture of the main body of the rotation sensor 54. In this embodiment, the detected portion 53 of the pulser ring 51 is parallel to the axle, and the holding portion 57 of the holding member 55 is provided so as to be inclined with respect to the axle. Therefore, as shown by the arrow A2 in FIG. 12, by sliding the rotation sensor 54 along the holding portion 57, the position of the rotation sensor 54 can be adjusted in both the axial direction and the radial direction.

  As described above, according to the present embodiment, the detected portion 53 of the pulser ring 51 is configured to extend in the axial direction, and therefore the hat portion 82 of the brake disc BD does not have to have a large diameter. Therefore, the outer diameter dimension of the brake disc BD itself can be reduced. Further, since the diameter of the brake disc BD can be reduced, even when the pulsar ring 51 is mounted inside the hat portion 82 of the brake disc BD, it is not necessary to radially expand the inner space of the wheel W. Further, since the diameter of the brake disc BD can be reduced, the unsprung weight can be reduced, and as a result, the riding comfort and running performance of the vehicle can be improved.

  Further, since the holding member 55 that holds the rotation sensor 54 has a position adjusting portion for adjusting the position of the rotation sensor 54 at least in the radial direction, the detection accuracy of the rotation sensor 54 can be improved. it can.

  The structure of the pulser ring 51 is not limited to the above example. A modified example will be described below.

(Modification 1)
FIG. 13 is a vertical cross-sectional view schematically showing a rotation detection mechanism 50A in the first modification of the embodiment of the present invention. The rotation detection mechanism 50A includes a pulsar ring 51A instead of the pulsar ring 51 shown in FIG. FIG. 14 shows a front view of the pulsar ring 51A as viewed from the inside in the vehicle width direction.

  The detected part 53 of the pulsar ring 51A extends in the axle direction similarly to the above-mentioned embodiment, but is formed in a conical shape so that the diameter becomes smaller toward the inside in the vehicle width direction. In this modification, the angle formed by the flange portion 52 and the detected portion 53 is substantially the same as the angle formed by the attachment portion 56 and the holding portion 57 of the holding member 55. In such a case, even if the main body of the rotation sensor 54 held by the holding member 55 does not have a bent shape as shown in FIG. Can be face-to-face.

(Modification 2)
FIG. 15 is a vertical cross-sectional view schematically showing rotation detection mechanism 50B in the second modification of the embodiment of the present invention. The rotation detection mechanism 50B includes a pulsar ring 51B instead of the pulsar ring 51 shown in FIG. FIG. 16 shows a front view of the pulsar ring 51B as seen from the inside in the vehicle width direction. Note that the rotation sensor 54 and its holding member 55 are not shown in FIG. 15.

  The pulsar ring 51B includes a contact portion 58 in addition to the flange portion 52 and the detected portion 53. Further, the flange portion 52 is formed in a ring shape. The size of the flange portion 52 is constant over the entire circumference.

  The contact portion 58 is connected to the outer diameter side end portion of the flange portion 52 and extends in the axle direction. That is, the pulsar ring 51B is bent so that the flange portion 52, the detected portion 53, and the contact portion 58 are substantially U-shaped. The axial length of the contact portion 58 may be shorter than the axial length of the detected portion 53. The contact portion 58 contacts the inner diameter surface 82c of the hat portion 82 of the brake disc BD (that is, the inner surface of the cylindrical portion 82b) in the mounted state.

  As described above, the pulsar ring 51B according to the present modification has the abutting portion 58 that abuts the inner diameter surface 82c of the hat portion 82 of the brake disc BD, so that the alignment can be easily performed when the pulsar ring 51B is attached to the brake disc BD. Can be done. Therefore, the work of attaching the pulsar ring 51B can be easily performed.

(Modification 3)
FIG. 17 is a vertical cross-sectional view schematically showing a rotation detection mechanism 50C in Modification 3 of the embodiment of the present invention. The rotation detection mechanism 50C includes a pulsar ring 51C instead of the pulsar ring 51 shown in FIG. FIG. 18 shows a front view of the pulsar ring 51C as viewed from the inside in the vehicle width direction. Note that the rotation sensor 54 and its holding member 55 are not shown in FIG. 17.

  The detected portion 53 of the pulsar ring 51C is connected to the outer diameter side end portion of the flange portion 52. In this case, the inner diameter surface of the detected portion 53, not the outer diameter surface, serves as the reading surface of the rotation sensor 54. That is, the rotation sensor 54 is attached to the main body casing 43 so that the detection surface 54a (FIG. 12) faces the outer diameter direction.

  In addition, although the passive type rotation detection mechanism 50 (50A, 50B, 50C) has been described in the above-described embodiment and its modification, the rotation detection mechanism may adopt an active type. In that case, for example, a known magnetic encoder can be adopted as the detected portion of the pulser ring. The magnetic encoder is an annular magnet in which N poles and S poles are repeatedly arranged in the circumferential direction. In this case, the rotation sensor 54 reads the strength of magnetism associated with the rotation of the magnetic encoder.

  Moreover, you may combine the several modified example mentioned above suitably.

  The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

  10 in-wheel motor drive device, 11 wheel hub bearing part, 12 outer ring, 13 inner fixing member, 15 fixed shaft, 18 carrier, 21 motor part, 22 motor rotating shaft, 23 rotor, 24 stator, 25 motor casing, 25b power line Terminal box, 25c signal line terminal box, 25v motor casing cover, 31 speed reducer, 32 input shaft, 33 input gear, 34, 36, 37, 39 intermediate gear, 35, 38 intermediate shaft, 40 output gear, 41 output shaft, 43 main body casing, 47 oil tank, 50, 50A, 50B, 50C rotation detection mechanism, 51, 51A, 51B, 51C, 151 pulsar ring, 52 flange part, 53 detected part, 54 rotation sensor, 55 holding member, 56 mounting Part, 57 holding part, 58 abutting part, 60 ball joint, 1 ball stud, 62 socket, 70 suspension device, 71 lower arm, 76 strut, 77 shock absorber, 78 coil spring, 80 tie rod, 81 brake ring, 82,182 hat part, 83 brake pad, 84 rotation angle sensor, 85 signal line Connection part, 87 signal line, 91 power line connection part, 93 power line, 101 vehicle body, 102 wheel housing, BD, 180 brake disc, W wheel wheel.

Claims (4)

In the in-wheel motor drive device, in which a brake disc is attached to the drive wheel, a pulsar ring is attached to the hat portion of the brake disc that is a rotating portion, and a rotation sensor that detects the rotation of the pulsar ring is attached to the fixed portion,
The pulsar ring is
A flange portion that is located radially outward of the flange of the wheel hub , extends in the radial direction, and is attached to the bottom wall portion of the hat portion with a bolt ,
An in-wheel motor drive device, comprising: a detected portion having an outer peripheral surface that is bent from an inner diameter side end portion of the flange portion and extends in the axle direction and that faces the rotation sensor. The in-wheel motor drive device according to claim 1, wherein the rotation sensor is attached to a casing of the in-wheel motor drive device with a bolt via a holding member . Before SL pulsar ring is connected to the outer diameter side end portion of the flange portion, further comprising a contact portion in contact with the inner surface of the hat portion, in-wheel motor drive device according to claim 1 or 2. Before SL holding member includes a position adjusting portion for enabling adjusting the position of the rotation sensor at least in the radial direction, in-wheel motor drive device according to claim 2.

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