JP2016038086A - Wheel driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel driving device capable of preventing vibration of an outer pin housing 50 of a cycloid type reduction gear 20 from being transmitted to a vehicle body, and easy to coaxially arrange the floatingly-supported reduction gear 20, a motor part 10 and a wheel hub bearing part 30.SOLUTION: An outer pin housing 50 held in a floating state on a casing 11b of a reduction gear 20 is provided with an elastic metal plate 60 for elastically supporting the same in the axial direction relative to an inner wall of the casing 11b of the reduction gear 20. A casing side plate 60c of the elastic metal plate 60 and the inner wall surface of the casing 11b are coupled via a face joint by friction force or a flexible coupling, so that the reduction gear 20 is aligningly arranged on the same axis with a motor part 10 and a wheel hub bearing part 30.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a wheel drive device that drives a drive wheel of an automobile.

  In a wheel drive device that uses an electric motor as a drive source and decelerates the rotation of the electric motor with a speed reducer to rotate the drive wheel, the rotation of the output shaft of the speed reducer is transmitted to a hub wheel provided on the output shaft. The in-wheel motor system that drives the drive wheel supported by the hub wheel, and the drive shaft is connected to the output shaft of the speed reducer via a joint, and the rotation of the drive shaft is transmitted to the hub wheel. And there is an on-board system that drives the driving wheel.

  Here, FIG. 1A shows an in-wheel motor system that directly drives the rear wheel 1 as a driving wheel by the wheel driving device A, and FIG. 1B shows a reduction gear (not shown) in the wheel driving device A. ) Is connected to a drive shaft 3 via a joint 2, and the rear wheel 1 is driven by the drive shaft 3.

  As shown in FIG. 11, the wheel drive device A includes a motor unit 110 that generates a driving force, a speed reducer 120 that decelerates and outputs the rotation of the motor unit 110, and a drive wheel (not shown) that outputs from the speed reducer 120. And a wheel hub bearing portion 130 for transmitting to the wheel. The wheel drive device A in FIG. 11 shows an in-wheel motor system. In the case of the on-board method, the above-described joint 2 and drive shaft 3 are connected between the wheel hub bearing portion and the speed reducer 120.

  Both in-wheel motor type and on-board type wheel drive devices A are required to be compact. Further, a large rotational driving torque is required to drive the rear wheel 1.

  In order to meet this requirement, the wheel drive device described in Patent Document 1 employs a cycloid reducer as the reducer 120 that reduces the rotation of the motor unit 110.

  The motor unit 110 and the speed reducer 120 are accommodated in the casing 111. The casing 111 includes a casing 111a on the motor unit 110 side and a casing 111b on the speed reducer 120 side. The casing 111a and the casing 111b are connected in the axial direction by bolts 121. The casing 111a and the casing 111b are separated from each other by a partition wall. It is partitioned by 111c.

  The motor unit 110 is of a radial gap type in which a stator 112 is provided on the inner peripheral surface of the casing 111a, and a rotor 113 is provided at an interval on the inner periphery of the stator 112.

  The rotor 113 has a motor shaft 114 in the center. The motor shaft 114 is connected to the input shaft 122 of the speed reducer 120 and inserted into the casing 111b of the speed reducer 120, and is rotated with respect to the casing 111a by the bearing 115. It is supported freely.

  The cycloid speed reducer 120 rotatably supports the curved plate 124 by an eccentric shaft portion 123 provided on the input shaft 122, and the corrugated tooth profile formed on the outer periphery of the curved plate 124 is formed on the casing 111 b of the speed reducer 120. The curved plate 124 is eccentrically oscillated by the rotation of the input shaft 122, and the rotation of the curved plate 124 is rotated coaxially with the input shaft 122. The output shaft 126 is arranged coaxially with the input shaft 122. The wheel hub 131 is rotated.

  The outer pin 125 is provided in an outer pin housing 150 that is floatingly supported on the inner diameter surface of the casing 111b of the speed reducer 120 via a gap. The outer pin housing 150 includes a cylindrical portion 150a and a pair of ring portions 150b extending radially inward from both axial end portions of the cylindrical portion 150a, and a speed reducer by keying or the like on the inner diameter surface or the width surface of the casing 111b. It is prevented from rotating with respect to 120 casings 111b.

  The ring portion 150b is provided with a plurality of outer pin holding holes 150c penetrating in the thickness direction, and both end portions of the outer pin 125 can be rotated via the needle roller bearing 151 in the outer pin holding hole 150c. It is supported.

  The outer pin side of the outer pin housing 150 that is supported by the outer pin holding hole 150c prevents the needle roller bearing 151 from coming off in the axial direction on the ring portion 150b of the outer pin housing 150 facing the inner wall in the axial direction of the casing 111b. A plate 160 is installed.

  By the way, the wheel drive device A of an electric vehicle is not limited to NVH performance, that is, “Noise” (noise and noise), “Vibration” (vibration transmitted from an engine or tire), in order to realize quietness like an electric vehicle. ), “Harshness” (vibration felt on the steering wheel, seat, and floor due to road surface differences) is required.

  For this reason, in the wheel drive device A employing the cycloid reduction gear 120, the outer pin housing 150 of the reduction gear 120 is floatingly supported in the casing 111b via a rubber member (Patent Document 1).

JP2012-25267A

  However, the wheel drive device A described in Patent Document 1 is effective in suppressing vibration transmission because the outer pin housing 150 of the speed reducer 120 is floatingly supported in the casing 111b via a rubber member. However, there is a problem that it is difficult to maintain the long-term quality and to manage the dimensions of the rubber member in a high temperature / oil environment.

  Further, the motor unit 110, the speed reducer 120, and the wheel hub bearing unit 130 need to be arranged on the same axis from the viewpoints of stable operation, sound vibration reduction, and life, but are floatingly supported in the casing 111b. In order to arrange the speed reducer 120 on the same axis, the same axis adjustment is required at the assembly stage, and there is a problem that the adjustment is difficult.

  Accordingly, the present invention is to provide a wheel drive device that has high NVH performance with improved long-term reliability and durability, and has the same axial centering function of a reduction gear that is floatingly supported in a casing. .

  In order to solve the above problems, in the present invention, a motor unit that generates a driving force, a speed reducer that decelerates and outputs the rotation of the motor unit, and a wheel that transmits the rotation output from the speed reducer to a drive wheel A hub bearing part, and the speed reducer is rotationally driven by the motor part, an input shaft having one end disposed inside the casing of the speed reducer, an eccentric shaft part provided on the input shaft, and an inner circumference A curved plate is mounted on the outer periphery of the eccentric shaft portion so as to be relatively rotatable and has a plurality of corrugated tooth profiles on the outer periphery at equal intervals in the circumferential direction, and a plurality of gear plates are arranged at equal intervals in the circumferential direction around the axis of the input shaft. And an outer pin for revolving and rotating the curved plate by meshing with the corrugated tooth profile of the curved plate as the eccentric shaft rotates, and an output shaft for taking out the rotation of the curved plate, and is held in a floating state in the casing of the speed reducer Outside In the wheel drive device that is a cycloid reduction gear that supports both ends of the outer pin on the inner housing, the outer pin housing is connected to the cylindrical portion provided on the inner diameter surface of the casing of the reduction gear and from the both ends of the cylindrical portion. The outer pin side plate is formed on the side surface of the ring portion of the outer pin housing, and the outer pin side plate and the casing of the reducer are provided. An elastic metal plate that elastically supports the outer pin housing in the axial direction is provided between the inner wall and the elastic metal plate. The elastic metal plate is provided between the outer pin side plate provided on the outer pin side plate side and the casing of the reduction gear. It consists of a casing side plate provided on the inner wall surface and an elastic column that connects the outer pin side plate and the casing side plate. And wherein the between the outer pin side plate or between the inner wall surface of the casing of the casing plate and reduction gear, and the interview if frictional force.

  Also, between the outer pin side plate and the outer pin side plate, or between the casing side plate and the inner wall surface of the reducer casing, through a flexible coupling that allows eccentricity, declination, and runout between the shafts. May be fastened.

  As the flexible coupling, an Oldham coupling or a V-groove roller coupling can be used.

  The outer pin side plate and the elastic metal plate can be integrally formed by pressing.

  In the wheel drive device according to the present invention, the wheel drive system may be an in-wheel motor system in which the hub wheel is directly rotated by the output shaft, or the drive shaft is connected to the output shaft of the speed reducer. Alternatively, an on-board system in which a hub wheel is connected to the drive shaft and the hub wheel is driven by the drive shaft may be used.

  In the wheel drive device according to the present invention, as described above, the outer pin housing that is floatingly supported by the casing of the speed reducer is connected to the cylindrical portion provided on the inner diameter surface of the casing of the speed reducer, and from both ends of the cylindrical portion. The outer pin side plate is formed on the side surface of the ring portion of the outer pin housing, and the outer pin side plate and the casing of the reducer are provided. By providing an elastic metal plate that elastically supports the outer pin housing in the axial direction between the inner wall and the use of a rubber member for vibration suppression can be abolished, so long-term reliability and durability Improvements can be made. Further, the cost can be reduced by reducing the number of parts.

  Further, since the outer pin housing is elastically held with respect to the casing via the elastic metal plate, the vibration of the outer pin housing is not easily transmitted to the vehicle body, and high NVH performance is obtained.

  The elastic metal plate is an elastic member that connects the outer pin side plate provided on the outer pin side plate side, the casing side plate provided on the inner wall surface of the reducer casing, and the outer pin side plate and the casing side plate. It consists of a pillar part, and is surface-bonded by frictional force between the outer pin side plate and the outer pin side plate, or between the casing side plate and the inner wall surface of the casing of the reduction gear. When the elastic metal plate is surface-joined by a frictional force, the reduction gear supported by floating can be aligned, and the motor portion, the reduction gear, and the wheel hub bearing portion can be arranged on the same axis.

  Also, Oldham coupling that allows eccentricity, declination, and runout between the shafts between the outer pin side plate and the outer pin side plate, or between the casing side plate and the inner wall surface of the reducer casing, By fastening through a flexible coupling such as a V-groove roller coupling, the reduction gear supported in a floating manner is aligned on the same axis with respect to the motor portion and the wheel hub bearing portion.

(A) is the schematic of the electric vehicle which employ | adopted the wheel drive device which concerns on this invention as an in-wheel motor system, (b) is the schematic of the electric vehicle which employ | adopted the wheel drive device which concerns on this invention as an onboard system It is. It is a front view which shows embodiment of the wheel drive device which concerns on this invention. It is a longitudinal cross-sectional view of the wheel drive device shown in FIG. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is sectional drawing which expands and shows the reduction gear of FIG. Embodiment of the elastic metal plate used for the reduction gear of the wheel drive device which concerns on this invention is shown, (a) is a front view, (b) is a side view. It is a longitudinal cross-sectional view which shows another embodiment of the wheel drive device which concerns on this invention. It is a disassembled front view of the Oldham coupling used for the fastening between the elastic metal plate and the casing of the reduction gear in the embodiment of FIG. It is a longitudinal cross-sectional view which shows another embodiment of the wheel drive device which concerns on this invention. FIG. 10 is an exploded front view of a V-groove roller coupling used for fastening between the elastic metal plate and the casing of the speed reducer in the embodiment of FIG. 9. It is a longitudinal cross-sectional view which shows the conventional wheel drive device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 2, a wheel drive device A according to the present invention is provided inside a wheel 1a in a rear wheel 1 as a drive wheel.

  As shown in FIG. 3, the wheel driving device A includes a motor unit 10 that generates a driving force, a speed reducer 20 that decelerates and outputs the rotation of the motor unit 10, and a drive wheel (not shown) that outputs from the speed reducer 20. And a wheel hub bearing 30 for transmitting to the wheel.

  The motor unit 10 and the speed reducer 20 are accommodated in the casing 11. The casing 11 includes a casing 11a on the motor unit 10 side and a casing 11b on the speed reducer 20 side. The casing 11a and the casing 11b are connected in the axial direction by bolts 21, and the casing 11a and the casing 11b are separated by a partition wall. It is partitioned by 11c.

  The motor unit 10 is of a radial gap type in which a stator 12 is provided on the inner peripheral surface of the casing 11a, and a rotor 13 is provided at an interval on the inner periphery of the stator 12.

  The rotor 13 has a motor shaft 14 in the center. The motor shaft 14 is connected to the input shaft 22 of the speed reducer 20 and is inserted into the casing 11b of the speed reducer 20, and is rotated with respect to the casing 11a by the bearing 15. It is supported freely.

  The casing 11b of the speed reducer 20 is provided with an oil tank 41 for lubricating oil at the lower portion. The lubricating oil in the oil tank 41 is sucked by the oil pump 42, and the lubricating oil is supplied to the motor unit 10 and the speed reducer 20 for lubrication. And cooling.

  An oil supply passage 43 that supplies lubricating oil to the inside of the speed reducer 20 extends rearward along the inside of the casing 11 a from the discharge port of the oil pump 42 that is driven by the rotation of the motor unit 10, and the rear end portion of the motor shaft 14. Through the internal passage 44, the internal passage 45 of the input shaft 22 of the speed reducer 20, and the input shaft oil supply holes 46 a and 46 b provided in the radial direction in the input shaft 22 so as to communicate with the internal passage 45. An oil supply hole 47 for supplying lubricating oil to the motor unit 10 is provided in the internal passage 44 of the motor shaft 14.

  The return path 48 for the lubricating oil includes a discharge port 49 provided at the bottom of the casing 11 b of the speed reducer 20 and a passage that reaches the suction port of the oil pump 42 through the oil tank 41.

  As shown in FIGS. 3 to 5, the cycloid speed reducer 20 is formed on the outer periphery of the curved plate 24 by rotatably supporting the curved plate 24 by an eccentric shaft portion 23 provided on the input shaft 22. The corrugated tooth profile 24a is engaged with the outer pin 25 disposed inside the casing 11b of the speed reducer 20, and the curved plate 24 is caused to eccentrically swing by the rotation of the input shaft 22, and the rotation of the curved plate 24 is rotated to the input shaft. The wheel hub 31 is rotated by outputting from an output shaft 26 arranged coaxially with the wheel 22.

  The number of outer pins 25 disposed inside the casing 11 b of the speed reducer 20 is greater than the corrugated tooth profile 24 a on the outer periphery of the curved plate 24.

  The outer pin 25 is provided in an outer pin housing 50 that is floatingly supported on the inner diameter surface of the casing 11b of the speed reducer 20 via a gap.

  One end of the input shaft 22 is connected to the motor shaft 14 of the rotor 13 by spline fitting and is driven to rotate by the motor unit 10, and an eccentric shaft 23 is provided at the other end. .

  A pair of eccentric shaft portions 23 are provided in the axial direction of the input shaft 22. The pair of eccentric shaft portions 23 is provided such that the center of the cylindrical outer diameter surface is 180 degrees out of phase in the circumferential direction, and a rolling bearing 28 is fitted to each outer diameter surface of the pair of eccentric shaft portions 23. Are combined.

  The input shaft 22 provided with the pair of eccentric shaft portions 23 is provided with a pair of counterweights 55 with a 180 ° phase shift in the circumferential direction so as to sandwich the pair of eccentric shaft portions 23.

  The curved plate 24 is rotatably supported by the input shaft 22 by a rolling bearing 28, and a corrugated tooth profile 24a formed on the outer periphery thereof is a trochoidal curved tooth profile. As shown in FIG. 4, the curved plate 24 has a plurality of pin holes 24b formed at equal intervals on a single circle centered on the rotation axis, and is formed in each of the pair of pin holes 24b arranged in the axial direction. The pin 29 is inserted with a margin, and a part of the outer periphery of the roller 29a rotatably supported by the inner pin 29 is in contact with a part of the inner periphery of the pin hole 24b.

  As described above, the speed reducer 20 includes a curved plate 24 as a revolving member that is rotatably held by the eccentric shaft portion 23, and a plurality of outer pins 25 that engage with the corrugated tooth profile 24a on the outer peripheral portion of the curved plate 24. And an output shaft 26 that outputs the rotational movement of the curved plate 24, and a center collar 24c that is attached to a gap between the curved plates 24 and abuts against the end surfaces of the curved plates 24 to prevent the curved plates from tilting.

  The output shaft 26 has a flange portion 26a and a shaft portion 26b. Inner pins 29 are fixed to the flange portion 26 a at equal intervals on a circumference centered on the rotation axis O of the output shaft 26. A wheel hub 31 is fixed to the outer diameter surface of the shaft portion 26b.

  The outer pins 25 are provided at equal intervals on the circumferential path of the rotation axis O of the input shaft 22. When the curved plate 24 revolves, the outer peripheral corrugated tooth profile 24a and the outer pin 25 engage with each other to cause the curved plate 24 to rotate.

  The outer pin 25 disposed in the casing 11b is not directly held by the casing 11b, but is held by an outer pin housing 50 that is floatingly supported with respect to the inner wall of the casing 11b as shown in FIG. . More specifically, the outer pin 25 is rotatably supported at both ends in the axial direction by needle roller bearings 51 with respect to the outer pin housing 50. Thus, by making the outer pin 25 rotatable with respect to the outer pin housing 50, the contact resistance due to the engagement with the curved plate 24 can be reduced.

  The outer pin housing 50 includes a cylindrical portion 50a and a pair of ring portions 50b extending radially inward from both axial ends of the cylindrical portion 50a, and is held in a floating state with respect to the casing 11b.

  The output shaft 26 is rotatably supported via a bearing 52 on the inner periphery of the pair of ring portions 50 b of the outer pin housing 50. The inner diameter surface of the flange portion 26 a of the output shaft 26 and the outer diameter surface of the input shaft 22 are supported through a bearing 53 so as to be relatively rotatable.

  The curved plate 24 is incorporated between the opposing flange portions 26 a of the output shaft 26. Further, both ends of the inner pin 29 penetrating the pin hole 24b of the incorporated curved plate 24 are supported by the flange portion 26a facing the output shaft 26.

  The plurality of inner pins 29 supported by the flange portions 26a opposed to the output shaft 26 are provided at equal intervals on a circumferential track centering on the rotation axis O of the input shaft 22, and have a frictional resistance with the curved plate 24. In order to reduce this, a needle roller bearing 29a is provided at a position where it abuts against the inner wall surface of the pin hole 24b of the curved plate 24. The inner diameter dimension of the pin hole 24b is set to be larger by a predetermined amount than the outer diameter dimension of the inner pin 29 (referred to as “maximum outer diameter including the needle roller bearing 29a”; the same applies hereinafter).

  A pair of ring portions 50b extending radially inward of the outer pin housing 50 are provided with a plurality of outer pin holding holes 50c penetrating in the thickness direction. The outer pin holding holes 50 c each extend in a direction parallel to the rotation axis O of the input shaft 22 and hold the outer ring 51 a of the needle roller bearing 51. Further, the corresponding outer pin holding holes 50c of the pair of ring portions 50b are provided at the same position in the circumferential direction and face each other. That is, the center axis of the pair of outer pin holding holes 50c coincides, and when the outer pin housing 50 is attached to the casing 11b, the center axis of the outer pin holding hole 50c becomes parallel to the rotation axis O of the input shaft 22. .

  Thereby, the outer pin 25 can be held in parallel with the rotation axis O of the input shaft 22. Since the outer pin holding holes 50c can be simultaneously formed by simultaneous processing, the central axes of the opposed outer pin holding holes 50c can be relatively easily matched.

  Further, from the viewpoint of reducing the weight of the wheel drive device A, the casings 11a and 11b are formed of a light metal such as an aluminum alloy or a magnesium alloy. On the other hand, it is desirable to form the outer pin housing 50, which requires high strength, from carbon steel.

  An outer pin side plate 60a is fixed to the side surface of the ring portion 50b of the outer pin housing 50 in order to prevent the outer pin 25 from coming off in the axial direction.

  As shown in FIGS. 6A and 6B, between the outer pin side plate 60a and the inner wall of the casing 11b of the speed reducer 20, the outer pin housing 50 is elastically supported by applying a preload in the axial direction. An elastic metal plate 60 is provided. 6A and 6B, one elastic metal plate 60 is in contact with the casing 11b, and the other elastic metal plate 60 is in contact with the partition wall 11c. These are the casing 11b in the claims. Means the inner wall (same below).

  The elastic metal plate 60 includes an outer pin side plate 60b provided on the outer pin side plate 60a side, a casing side plate 60c provided on the inner wall surface of the casing 11b of the speed reducer 20, and the outer pin side plate 60b and the casing side. It consists of the elastic column part 60d which connects the plate 60c.

  In the embodiment shown in FIG. 3, the shaft center of the outer pin housing 50 that is floatingly supported by the casing 11 b of the speed reducer 20 is arranged on the same shaft center with the shaft center of the motor unit 10 and the wheel hub bearing unit 30. Furthermore, the surface side joining by the frictional force is made between the casing side plate 60c and the inner wall surface of the casing 11b of the speed reducer 20.

  Further, the outer pin side plate 60b and the outer pin side plate 60a may be aligned with each other by surface bonding using a frictional force.

  Next, in the embodiment shown in FIG. 7 and FIG. 9, a motor using a flexible coupling such as Oldham coupling 70 and V-groove roller coupling 80 that allows eccentricity, declination, and runout between shafts is used. The part 10, the speed reducer 20, and the wheel hub bearing part 30 are arranged so as to be aligned on the same axis.

  In the embodiment shown in FIG. 7, an elastic metal plate 60 is provided between the outer pin side plate 60 a and the inner wall of the casing 11 b of the speed reducer 20 to elastically support the outer pin housing 50 by applying a preload in the axial direction. The casing side plate 60c of the elastic metal plate 60 is fastened to the inner wall surface of the casing 11b of the speed reducer 20 via the Oldham coupling 70.

  As shown in FIG. 8, the Oldham coupling 70 includes a slider plate 70c between the hub plate 70a and the hub plate 70b, and includes a protrusion 72 provided on the hub plate 70b and a groove 73 provided on the slider plate 70c. A joint that fits the projection 71 provided on the slider plate 70c and the groove 74 provided on the hub plate 70a and transmits power while sliding the slider plate 70c between the hub plate 70a and the hub plate 70b. Yes, it has the function of allowing eccentricity, declination, and runout between shafts.

  An Oldham coupling 70 shown in FIG. 8 is an example in which a hub plate 70 a is integrally formed on a casing side plate 60 c of an elastic metal plate 60.

  In the embodiment shown in FIG. 7, the Oldham coupling 70 is disposed between the casing side plate 60 c of the elastic metal plate 60 and the inner wall of the casing 11 b of the speed reducer 20, but the outer pin side plate 60 a and the elastic metal plate 60 are arranged. It may be arranged between the outer pin side plate 60b.

  Next, in the embodiment shown in FIG. 9, an elastic metal plate that elastically supports the outer pin housing 50 by applying a preload in the axial direction between the outer pin side plate 60 a and the inner wall of the casing 11 b of the speed reducer 20. 60, and the casing side plate 60 c of the elastic metal plate 60 is fastened to the inner wall surface of the casing 11 b of the speed reducer 20 via the V-groove roller coupling 80.

  As shown in FIG. 10, in the V-groove roller coupling 80, a slider plate 80c is provided between the hub plate 80a and the hub plate 80b, the opposed surfaces of the hub plate 80a and the slider plate 80c, the hub plate 80b and the slider plate 80c. Is a joint that transmits power while sliding the V-groove 80d and the roller 80e by incorporating a roller 80e into the V-groove 80d. Has a function to allow declination and deflection.

  A V-groove roller coupling 80 shown in FIG. 10 is an example in which a hub plate 80 a is integrally formed on a casing-side plate 60 c of an elastic metal plate 60.

  The elastic metal plate 60 is provided on both sides of the outer pin housing 50 in the axial direction so as to sandwich the outer pin housing 50. The outer pin housing 50 is elastically held by the elastic metal plates 60 on both sides with respect to the outer side inner wall surface of the casing 11b of the reduction gear 20 and the inner side partition wall 11c, and the vibration of the reduction gear 20 is applied to the vehicle body. Suppressed from being transmitted.

  As shown in FIG. 6, the elastic column part 60d of the elastic metal plate 60 is formed by pressing through holes 60e in the circumferential direction at predetermined intervals on an annular wall connecting the outer pin side plate 60b and the casing side plate 60c. Can be formed. Since the outer pin side plate 60b is on the outer diameter side of the casing side plate 60c, the elastic column part 60d is formed in a conical shape. Further, since the necessary elastic force can be obtained freely by changing the number of through holes 60e, the degree of freedom in design is improved.

  As a material of the elastic metal plate 60, cold rolled steel (SPCC), polished special steel strip (spring steel SUP, SCM415, SCr420), and stainless steel can be used.

  As shown in FIG. 3, the wheel hub bearing portion 30 includes an inner ring member 32 fixedly connected to the outer diameter surface of the shaft portion 26b of the output shaft 26, and an outer ring that rotatably holds the inner ring member 32 with respect to the casing 11b. A member 33. The inner ring member 32 and the outer ring member 33 constitute a double-row angular ball bearing, and a double-row rolling element 34 is installed between the inner ring member 32 and the outer ring member 33. The inner ring member 32 is integrally provided with a flange portion 35, and a driving wheel (not shown) is fixedly connected to the flange portion 35 by a bolt 36.

The operation principle of the wheel drive device A having the above configuration will be described in detail.
For example, the motor unit 10 receives an electromagnetic force generated by supplying an alternating current to the coil of the stator 12, and the rotor 13 made of a permanent magnet or a magnetic material rotates.

  Thereby, when the motor shaft 14 connected to the rotor 13 rotates, the curved plate 24 revolves around the rotation axis O of the motor shaft 14. At this time, the outer pin 25 engages with the curved waveform of the curved plate 24 so as to make rolling contact, and the curved plate 24 rotates in the direction opposite to the rotation of the motor shaft 14.

  The outer diameter of the inner pin 29 inserted through the pin hole 24b of the curved plate 24 is smaller than the inner diameter of the pin hole 24b, and comes into contact with the inner wall surface of the pin hole 24b as the curved plate 24 rotates. Thereby, the revolution movement of the curved plate 24 is not transmitted to the inner pin 29, and only the rotational motion of the curved plate 24 is transmitted to the wheel hub bearing portion 30 via the output shaft 26.

  At this time, the output shaft 26 arranged coaxially with the rotation axis O extracts the rotation of the curved plate 24 as the output shaft of the speed reducer 20, and the rotation of the motor shaft 14 is decelerated by the speed reducer 20 and transmitted to the output shaft 26. Therefore, even when the low torque, high rotation type motor unit 10 is employed, it is possible to transmit the necessary torque to the drive wheels.

Note that the reduction ratio of the speed reducer 20 configured as described above is calculated as (Z _A −Z _B ) / Z _B, where Z _{A is} the number of outer pins 25 and Z _B is the number of waveforms of the curved plate 24. In the embodiment shown in FIG. 4, since Z _A = 12 and Z _B = 11, the reduction ratio is 1/11, and a very large reduction ratio can be obtained.

  Thus, by adopting the reduction gear 20 that can obtain a large reduction ratio without using a multistage configuration, a compact and high reduction ratio wheel drive device A can be obtained. Further, since the outer pin 25 is rotatable with respect to the outer pin housing 50 and the needle roller bearing 29a is provided at a position where the outer pin 25 contacts the curved plate 24, the frictional resistance is reduced. 20 transmission efficiency is improved.

  By employing the wheel drive device A according to the present invention for an electric vehicle, the unsprung weight can be suppressed. As a result, an electric vehicle with excellent running stability can be obtained.

  Further, in the above-described embodiment, two curved plates 24 of the speed reducer 20 are provided with a 180 ° phase change. However, the number of curved plates can be arbitrarily set. For example, three curved plates are provided. When provided, it is preferable to change the phase by 120 °.

  In addition, although description of the action | operation in the said embodiment was performed paying attention to rotation of each member, the motive power containing a torque is actually transmitted from the motor part 10 to a driving wheel. Therefore, the power decelerated as described above is converted into high torque.

  In the description of the operation in the above-described embodiment, power is supplied to the motor unit 10 to drive the motor unit 10 and the power from the motor unit 10 is transmitted to the drive wheels. When the vehicle decelerates or goes down a hill, the power from the drive wheel side is converted into high-rotation low-torque rotation by the speed reducer 20 and transmitted to the motor unit 10. good. Furthermore, the electric power generated here may be stored in a battery and used later for driving the motor unit 10 or for operating other electric devices provided in the vehicle.

  Moreover, in the said embodiment, the radial gap motor provided with the stator 12 fixed to the casing 11a at the motor part 10, and the rotor 13 arrange | positioned in the position which faces the inner side of the stator 12 with a radial clearance. Although the example which employ | adopted was shown, the motor of arbitrary structures is applicable not only to this but. For example, an axial gap motor in which the stator and the rotor are arranged to face each other via a gap opened in the axial direction may be used.

  Furthermore, the electric vehicle equipped with the wheel drive device A according to the present invention may have the rear wheels as drive wheels, the front wheels as drive wheels, or a four-wheel drive vehicle. In the present specification, “electric vehicle” is a concept including all vehicles that obtain driving force from electric power, and should be understood as including, for example, a hybrid vehicle.

  The wheel drive device A according to the present invention has an outer pin housing 50 that is floatingly supported on the inner diameter surface of the casing 11b of the cycloid reducer 20 via a gap via an elastic metal plate 60. Since it is elastically held in the direction, vibration of the outer pin housing 50 is hardly transmitted to the vehicle body, and high NVH performance is obtained.

  Therefore, the use of a rubber member for suppressing vibration can be eliminated, so that long-term reliability and durability are improved.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

1: Rear wheel 1a: Wheel 10: Motor unit 11: Casing 11a: Casing 11b: Casing 11c: Partition wall 12: Stator 13: Rotor 14: Motor shaft 15: Bearing 20: Reducer 21: Bolt 22: Input shaft 23: Eccentric shaft portion 24: curved plate 24a: corrugated tooth profile 24b: pin hole 24c: center collar 25: outer pin 26: output shaft 26a: flange portion 26b: shaft portion 28: rolling bearing 29: inner pin 29a: needle roller bearing 30 : Wheel hub bearing part 31: Wheel hub 32: Inner ring member 33: Outer ring member 34: Rolling element 35: Flange part 36: Bolt 41: Oil tank 42: Oil pump 43: Oil supply passage 44: Internal passage 45: Internal passage 46a: Input shaft oil supply hole 46b: Input shaft oil supply hole 47: Oil supply hole 48: Return passage 49: Discharge port 50: Outer pin Housing 50a: Cylindrical part 50b: Ring part 50c: Outer pin holding hole 51: Needle roller bearing 51a: Outer ring 52: Bearing 53: Bearing 55: Counterweight 60: Elastic metal plate 60a: Outer pin side plate 60b: Outer pin side Side plate 60c: Casing side plate 60d: Elastic column part 60e: Through hole 70: Oldham coupling 70a: Hub plate 70b: Hub plate 70c: Slider plate 71: Protrusion 72: Protrusion 73: Groove 80: V-groove roller coupling 80a : Hub plate 80b: Hub plate 80c: Slider plate 80d: V groove 80e: Roller A: Wheel drive device O: Rotation axis

Claims (7)

  A motor unit that generates a driving force, a speed reducer that decelerates and outputs the rotation of the motor unit, and a wheel hub bearing unit that transmits the rotation output from the speed reducer to a driving wheel. An input shaft that is rotationally driven by the motor unit, an eccentric shaft portion provided on the input shaft, and an inner periphery is attached to the outer periphery of the eccentric shaft portion so as to be relatively rotatable, and the outer periphery has a plurality of waveform teeth at regular intervals in the circumferential direction. A plurality of curved plates are arranged at equal intervals in the circumferential direction around the axis of the input shaft in the speed reducer casing, and mesh with the corrugated tooth profile of the curved plate as the eccentric shaft rotates, causing the curved plate to revolve and rotate. In a wheel drive device comprising an outer pin and an output shaft for taking out the rotation of a curved plate, and a cycloid reducer that supports both ends of the outer pin in an outer pin housing held in a floating state in the casing of the speed reducing portion The outer pin housing is constituted by a cylindrical portion provided on the inner diameter surface of the casing of the speed reducer, and a pair of ring portions that are formed inward from both ends of the cylindrical portion and hold both end portions of the outer pin, An outer pin side plate is provided on the side surface of the ring portion of the outer pin housing, and an elastic metal plate that elastically supports the outer pin housing in the axial direction is provided between the outer pin side plate and the inner wall of the reducer casing. The elastic metal plate is an elastic connecting the outer pin side plate provided on the outer pin side plate side, the casing side plate provided on the inner wall surface of the reduction gear casing, and the outer pin side plate and the casing side plate. It consists of a pillar part, between the outer pin side plate and the outer pin side plate, or between the casing side plate and the inner wall surface of the reducer casing Wheel drive unit being characterized in that the interview if frictional forces between.   A motor unit that generates a driving force, a speed reducer that decelerates and outputs the rotation of the motor unit, and a wheel hub bearing unit that transmits the rotation output from the speed reducer to a driving wheel. An input shaft that is rotationally driven by the motor unit, an eccentric shaft portion provided on the input shaft, and an inner periphery is attached to the outer periphery of the eccentric shaft portion so as to be relatively rotatable, and the outer periphery has a plurality of waveform teeth at regular intervals in the circumferential direction. A plurality of curved plates are arranged at equal intervals in the circumferential direction around the axis of the input shaft in the speed reducer casing, and mesh with the corrugated tooth profile of the curved plate as the eccentric shaft rotates, causing the curved plate to revolve and rotate. In a wheel drive device comprising an outer pin and an output shaft for taking out the rotation of a curved plate, and a cycloid reducer that supports both ends of the outer pin in an outer pin housing held in a floating state in the casing of the speed reducing portion The outer pin housing is constituted by a cylindrical portion provided on the inner diameter surface of the casing of the speed reducer, and a pair of ring portions that are formed inward from both ends of the cylindrical portion and hold both end portions of the outer pin, An outer pin side plate is provided on the side surface of the ring portion of the outer pin housing, and an elastic metal plate that elastically supports the outer pin housing in the axial direction is provided between the outer pin side plate and the inner wall of the reducer casing. The elastic metal plate is an elastic connecting the outer pin side plate provided on the outer pin side plate side, the casing side plate provided on the inner wall surface of the reduction gear casing, and the outer pin side plate and the casing side plate. It consists of a pillar part, between the outer pin side plate and the outer pin side plate, or between the casing side plate and the inner wall surface of the reducer casing During wheel drive unit, characterized in that they have entered into through the flexible coupling to allow eccentricity, declination and deflection between the axes of.   The wheel drive device according to claim 2, wherein the flexible coupling is an Oldham coupling.   The wheel drive device according to claim 2, wherein the flexible coupling is a V-groove roller coupling.   The wheel drive device according to any one of claims 1 to 4, wherein the outer pin side plate and the outer pin side plate are integrated.   The wheel drive device according to any one of claims 1 to 5, which is an on-board system in which a joint and a drive shaft are interposed between the speed reducer and the wheel hub bearing portion.   The wheel drive device according to any one of claims 1 to 5 of an in-wheel motor system.

Images