JP2016056926A - Wheel driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel driving device using a cycloid type speed reducer 20, which eliminates mechanical interference between components, can suppress occurrence of looseness, and has high NVH performance.SOLUTION: An elastic member 29c is arranged in a clearance between a pin hole 24b of a curve plate 24 and an inner pin 29 contacting with the pin hole 24b; a preload is imparted by elastic force of the elastic member 29c between the inner pin 29 and the pin hole 24b of the curve plate 24; looseness due to a predetermined clearance is reduced; and thereby high NVH performance can be obtained.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. 8, 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. 8 shows an in-wheel motor system. In the case of the on-board method, the wheel hub bearing portion 130 and the speed reducer 120 are connected via the joint 2 and the drive shaft 3 described above.

  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 ends of the cylindrical portion 150a. The casing 111b of the speed reducer 120 is secured to the inner diameter surface of the casing 111b by a key or the like. Against rotation.

  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.

  An output shaft 126 is rotatably supported via a bearing 152 on the inner periphery of the pair of ring portions 150 b of the outer pin housing 150. Further, the inner diameter surface of the flange portion 126 a of the output shaft 126 and the outer diameter surface of the input shaft 122 are supported via a bearing 153 so as to be relatively rotatable.

  The curved plate 124 is incorporated between the opposing flange portions 126 a of the output shaft 126. Further, both ends of the inner pin 129 penetrating the pin hole 124b of the incorporated curved plate 124 are supported by the flange portion 126a facing the output shaft 126.

  The plurality of inner pins 129 supported by the opposing flange portions 126a of the output shaft 126 are provided at equal intervals on a circumferential track centering on the rotation axis O of the input shaft 122, and have a frictional resistance with the curved plate 124. In order to reduce this, a needle roller bearing 129a is provided at a position where it abuts against the inner wall surface of the pin hole 124b of the curved plate 124. The inner diameter dimension of the pin hole 124b is set to be larger than the outer diameter dimension of the inner pin 129 (referred to as “maximum outer diameter including the needle roller bearing 129a”; the same applies hereinafter).

  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.

  Moreover, in the wheel drive device A that employs 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

  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.

  The cycloid speed reducer 120 of the wheel drive device A is used at high speed rotation, and in order to further improve the NVH performance, high accuracy of micron order is required as dimensional accuracy between components.

  However, obtaining such an accuracy that there is no gap with the inner pin 129 that contacts the pin hole 124b of the curved plate 124 leads to an increase in cost in the mass production process, and mechanical interference between components is likely to occur. .

  For this reason, it is indispensable in mass production to provide a predetermined gap between the inner pin 129 that contacts the pin hole 124b of the curved plate 124 and reduce the accuracy so as not to cause mechanical interference.

  However, if there is a gap with the inner pin 129 that contacts the pin hole 124b of the curved plate 124, rattling is likely to occur, the rotational operation is not stable, and it may cause sound vibration.

  Accordingly, the present invention is intended to provide a wheel drive device that can suppress the occurrence of backlash between the inner pin that contacts the pin hole of the curved plate and has high NVH performance.

  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 The speed reducer is attached to an input shaft that is rotationally driven by the motor portion, an eccentric shaft portion provided on the input shaft, and an inner periphery thereof rotatably attached to an outer periphery of the eccentric shaft portion. A curved plate having a plurality of corrugated teeth on the outer periphery at equal intervals in the circumferential direction, and a plurality of curved plates arranged at equal intervals in the circumferential direction around the axis of the input shaft, and with the rotation of the eccentric shaft portion, An outer pin that revolves and rotates the curved plate by meshing with the corrugated tooth profile, and an inner pin that contacts the inner wall surface of the pin hole provided at equal intervals on a circumferential track centering on the axis of the input shaft. Support both ends and take out the rotation of the curved plate In the wheel drive device which is a cycloidal speed reducer and a shaft, characterized by being applied a preload between the pin holes and the inner pins of said pin.

  In order to apply a preload between the pin hole of the curved plate and the inner pin that contacts the pin hole, for example, a predetermined gap provided between the pin hole of the curved plate and the inner pin that contacts the pin hole Is provided between the outer peripheral surface of the inner pin and a bearing provided on the outer peripheral surface, and an elastic member is disposed in a gap provided between the outer peripheral surface of the inner pin and the bearing.

  Also, a sleeve is inserted into the outer peripheral surface of the inner pin, a predetermined gap is provided between the inner peripheral surface of the sleeve and the outer peripheral surface of the inner pin, and an elastic member is disposed in the gap to place the inner pin and the curved plate pin. A preload may be applied between the holes.

  In the wheel drive device according to the present invention, as described above, by applying a preload between the pin hole of the curved plate and the inner pin in contact with the pin hole, the occurrence of play can be suppressed. By providing a predetermined gap between the pin hole of the curved plate and the inner pin in contact with the pin hole, it becomes possible to relax the accuracy so as not to cause mechanical interference.

(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. It is a side view which shows an example of the elastic member used for the reduction gear of the wheel drive device shown in 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 side view, (b) is a front view. 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. The outer pin housing 50 is prevented from rotating with respect to the casing 11b of the speed reducer 20 by keying or the like.

  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 needle roller bearing 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 rotation of the curved plate 24, and a center collar 24c that is attached to a gap between the curved plates 24 and contacts the end surfaces of the curved plates 24 to prevent the curved plate 24 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 end portions of the cylindrical portion 50a. The outer pin housing 50 is floated with respect to the casing 11b by keying or the like on the inner diameter surface of the casing 11b. Held in a state.

  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.

  Between the inner wall surface of the pin hole 24b of the curved plate 24 and the inner pin 29 abutting against the inner wall surface, in order to avoid mechanical interference between parts assumed from the geometric dimension tolerance in the mass production drawing. In addition, a predetermined gap is provided. A preload is applied between the inner wall surface of the pin hole 24b of the curved plate 24 and the inner pin 29 in order to reduce the play caused by the set gap and realize stable operation and reduction of sound vibration. ing.

  Specific examples of means for applying a preload between the inner wall surface of the pin hole 24b of the curved plate 24 and the inner pin 29 include the following means.

  As shown in FIG. 5, a sleeve 29b is inserted between the outer peripheral surface of the inner pin 29 and the needle roller bearing 29a, and between the inner peripheral surface of the sleeve 29b and the outer peripheral surface of the inner pin 29, a machine between components. A predetermined gap for avoiding mechanical interference is provided, and an elastic member 29c such as rubber, a spring ring or the like is disposed in the gap, and a preload is applied between the inner wall surface of the pin hole 24b of the curved plate 24 and the inner pin 29. Has been granted.

  FIG. 6 is an external view of a spring ring that is the elastic member 29c.

  Next, 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 portion 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 FIG. 3, between the outer side outer pin side plate part 60a and the outer side wall 11d of the casing 11b, between the inner side outer pin side plate part 60a and the inner side partition wall 11c. Is provided with an elastic metal plate 60, by which the outer pin housing 50 is elastically held against the outer side wall 11 d and the inner side partition wall 11 c of the casing 11 b of the speed reducer 20. Thus, the vibration of the speed reducer 20 is suppressed from being transmitted to the vehicle body.

  As shown in FIGS. 7A and 7B, the elastic metal plate 60 includes an outer pin side plate portion 60b provided on the outer pin side plate portion 60a side and an outer side wall 11d of the casing 11b. It comprises a casing side plate portion 60c provided on the inner side partition wall 11c side and an elastic column portion 60d provided between the outer pin side side plate portion 60b and the casing side plate portion 60c.

  The elastic column part 60d can be formed by pressing through holes 60e at predetermined intervals in the circumferential direction on the annular wall connecting the outer pin side plate part 60b and the casing side plate part 60c. Since the outer pin side plate portion 60g is on the outer diameter side of the casing side plate portion 60c, the elastic column portion 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 composed of an inner ring separate from the hub ring 31 integrally provided with the 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 particularly in the case of the in-wheel motor system. 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. In addition, since the elastic metal plate as a member that supports the outer pin side plate portion 60a and the outer pin housing 50 in a floating manner is integrally provided, the number of parts can be reduced and the cost can be reduced.

  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.

DESCRIPTION OF SYMBOLS 10: Motor part 11: Casing 11a: Casing 11b: Casing 11c: Partition wall 11d: Side wall 12: Stator 13: Rotor 14: Motor shaft 15: Bearing 20: Reduction gear 21: Bolt 22: Input shaft 23: Eccentric shaft part 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 29b: Sleeve 29c : Elastic member 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 portion 50b: ring portion 50c: outer pin holding hole 51: bearing 51a: outer ring 52: bearing 53: bearing 55: counterweight 60: elastic metal plate 60a: outer pin side plate Part 60b: casing side plate part 60c: elastic column part 60e: through-hole A: wheel drive device

Claims (5)

  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. An output shaft that supports the outer pin and both ends of the inner pin that contacts the inner wall surface of the pin hole provided at equal intervals on a circumferential track centering on the axis of the input shaft on the curved plate, and extracts the rotation of the curved plate Wheel drive made into a cycloid reducer with In the device, a wheel drive device being characterized in that impart preload between the pin holes and the inner pins of said pin.   A predetermined gap provided between the pin hole of the curved plate and the inner pin in contact with the pin hole is provided between the outer peripheral surface of the inner pin and the bearing provided on the outer peripheral surface, and the outer periphery of the inner pin. 2. The wheel drive device according to claim 1, wherein an elastic member is disposed in a gap provided between the surface and the bearing to apply a preload between the inner pin and the pin hole of the curved plate.   A sleeve is inserted into the outer peripheral surface of the inner pin, a predetermined gap is provided between the inner peripheral surface of the sleeve and the outer peripheral surface of the inner pin, and an elastic member is disposed in the gap to place the inner pin and the curved plate pin. The wheel drive device according to claim 1 or 2, wherein a preload is applied between the holes.   The wheel drive device according to any one of claims 1 to 3, wherein 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 3, which is an in-wheel motor system.

Images