JP2016142362A - In-wheel motor drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a width dimension of an in-wheel motor drive unit 21 by devising an arrangement of an output shaft support bearing 90 of a reduction gear B.SOLUTION: Inner pins 37 are fixed at equal intervals on a circumference with a rotation axial line of an output shaft 33 of a reduction gear B as a center, a wheel hub C is arranged at an outside diameter face of a shaft part 33b of the output shaft 33 in a torque transmittable state, a flange part 33a and a stabilizer 33d of the output shaft 33 are connected to each other via a plurality of the inner pins 37, the output shaft 33 rotates integrally with the stabilizer 33d, the flange part 33a and the stabilizer 33d of the output shaft 33 are rotatably supported to an internal periphery of a flange part 51 of an outer pin housing 50 via an output shaft support bearing 90, and by arranging the output shaft support bearing 90 at an outside diameter side of both ends of the inner pins 37, an axial dimension is shortened more than before, and a PCD of the output shaft support bearing 90 is enlarged.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an in-wheel motor drive device using a cycloid reduction gear.

  As shown in FIG. 9, the in-wheel motor drive device 121 includes a motor unit A that generates a driving force, a speed reducer B that decelerates and outputs the rotation of the motor unit A, and an output from the speed reducer B as driving wheels. And a wheel hub C to be transmitted to the vehicle.

  The motor part A and the speed reducer B are accommodated in the casing 122. The casing 122 includes a casing 122a on the motor part A side and a casing 122b on the reduction gear B side.

  The motor part A uses a radial gap type of which a stator 123 is provided on the inner peripheral surface of the casing 122a and a rotor 124 is provided at an interval on the inner periphery of the stator 123.

  The rotor 124 has a motor shaft 124a in the center. The motor shaft 124a is connected to the input shaft 130 of the speed reducer A and is inserted into the casing 122b of the speed reducer B. The bearings 125a and 125b are connected to the casing 122a. And is supported rotatably.

  The casing 122b of the speed reducer B is provided with an oil tank 141 for lubricating oil at the lower portion. The lubricating oil in the oil tank 141 is sucked by the oil pump 142, and the lubricating oil is supplied to the motor unit A and the speed reducer B for lubrication. And cooling is performed (Patent Document 1).

  An oil supply passage 143 that supplies lubricating oil to the inside of the speed reducer B extends along the inside of the casing 122a from the discharge port of the oil pump 142 that is driven by using the output rotation of the speed reducer B that decelerates the rotation of the motor unit A. And a passage extending from the rear of the casing 122a through the internal passage 144 of the motor shaft 124a and the internal passage 145 of the input shaft 130 of the speed reducer B into the casing 122b of the speed reducer B.

  The lubricating oil return passage 146 is configured by a passage that reaches the suction port of the oil pump 142 through the discharge port 147 and the oil tank 141 provided at the bottom of the casing 122b of the speed reducer B.

  As shown in FIGS. 9 to 13, the cycloid reduction gear B supports two curved plates 131 rotatably by eccentric shaft portions 130 a and 130 b provided on the input shaft 130, and these curved plates 131. Is engaged with the outer pin 132 supported on the inner side of the outer pin housing 150 located on the inner diameter surface of the casing 122b of the reduction gear B via a gap, and the input shaft 130 is rotated. The curved plate 131 is eccentrically oscillated, the rotation of the curved plate 131 is output from the output shaft 133 arranged coaxially with the input shaft 130, and the wheel hub C is rotated.

  The number of outer pins 132 supported on the inner side of the outer pin housing 150 is larger than the corrugated tooth profile 131 a on the outer periphery of the curved plate 131.

  The outer pin 132 is supported by the outer pin housing 150 located on the inner diameter surface of the casing 122b of the reduction gear B via a gap. The outer pin housing 150 is floatingly supported by floating bolts (not shown) on the outer side and the inner side with respect to the casing 122b of the speed reducer B.

  As shown in FIGS. 12 and 13, the outer pin housing 150 has a cylindrical shape having a pair of flange portions 151 protruding in the axial direction on the inner diameter side of both end faces in the axial direction.

  As shown in FIG. 9, one end of the input shaft 130 is connected to the motor shaft 124a of the rotor 124 by spline fitting and is driven to rotate by the motor portion A, and the other end is an eccentric shaft. Parts 130a and 130b are provided.

  As shown in FIG. 10, a pair of eccentric shaft portions 130 a and 130 b are provided in the axial direction of the input shaft 130. The pair of eccentric shaft portions 130a and 130b is provided such that the center of the cylindrical outer diameter surface is 180 degrees out of phase in the circumferential direction, and rolls to the outer diameter surface of each of the pair of eccentric shaft portions 130a and 130b. A bearing 134 is fitted.

  The input shaft 130 provided with the pair of eccentric shaft portions 130a and 130b is provided with a pair of counterweights 135 with a 180 ° phase shift in the circumferential direction so as to sandwich the pair of eccentric shaft portions 130a and 130b.

  As shown in FIGS. 10 and 11, the curved plate 131 is rotatably supported on the input shaft 130 by a rolling bearing 134, and the corrugated tooth profile 131a formed on the outer periphery thereof is a trochoidal curved tooth profile. As shown in FIG. 11, in the curved plate 131, a plurality of pin holes 136 are formed at equal intervals on one circle centered on the rotational axis, and each of the pair of pin holes 136 aligned in the axial direction is formed in the curved plate 131. The pin 137 is inserted with a margin, and a part of the outer periphery of the roller bearing 137 a rotatably supported by the inner pin 137 is in contact with a part of the inner periphery of the pin hole 136.

  As shown in FIG. 10, the speed reducer B includes a curved plate 131 as a revolving member that is rotatably held by the eccentric shaft portions 130 a and 130 b, and a plurality of engaging teeth 131 a on the outer peripheral portion of the curved plate 131. An outer pin 132, an output shaft 133 that outputs the rotation of the curved plate 131, a center collar 138 that is attached to a gap between the curved plates 131 and abuts against the end surfaces of the curved plates 131 to prevent the curved plate 131 from tilting; Is provided.

  The output shaft 133 has a flange portion 133a and a shaft portion 133b. As shown in FIGS. 9 and 10, inner pins 137 are fixed to the flange portion 133 a at equal intervals on a circumference centered on the rotation axis of the output shaft 133. A wheel hub C is disposed on the outer diameter surface of the shaft portion 133b so that torque can be transmitted by serration (or spline). The flange portion 133a and the stabilizer 133d are connected via the plurality of inner pins 137, and the output shaft 133 and the stabilizer 133d rotate integrally. A pump drive shaft 133c connected to the inner rotor of the oil pump 142 is integrally provided at the end of the stabilizer 133d on the motor part A side.

  As shown in FIG. 11, the outer pins 132 are provided at equal intervals on the circumferential orbit of the rotation axis of the input shaft 130. When the curved plate 131 revolves, the corrugated tooth profile 131a on the outer periphery engages with the outer pin 132 to cause the curved plate 131 to rotate.

  As shown in FIG. 10, an output shaft 133 and a stabilizer 133 d are rotatably supported on the inner periphery of the flange portion 151 of the outer pin housing 150 via an output shaft support bearing 190. An inner diameter surface of the flange portion 133a of the output shaft 133 and the stabilizer 133d and an outer diameter surface of the input shaft 130 are supported through a rolling bearing 191 so as to be relatively rotatable.

  The curved plate 131 is incorporated between the flange portion 133a and the stabilizer 133d facing the output shaft 133. Further, both ends of the inner pin 137 penetrating the pin hole 136 of the curved plate 131 are supported by the flange portion 133a and the stabilizer 133d facing the output shaft 133.

  The plurality of inner pins 137 supported by the flange portions 133a opposed to the output shaft 133 are provided at equal intervals on a circumferential track centering on the rotation axis of the input shaft 130, thereby reducing the frictional resistance with the curved plate 131. For this purpose, a needle roller bearing 137a is provided at a position where it abuts against the inner wall surface of the pin hole 136 of the curved plate 131. The inner diameter dimension of the pin hole 136 is set to be larger than the outer diameter dimension of the inner pin 137 by a predetermined amount.

  As shown in FIG. 9, the wheel hub C includes an inner member 181 fitted and connected to the outer diameter surface of the shaft portion 133 b of the output shaft 133 so that torque can be transmitted by serration (or spline), and an inner member. And an outer member 182 that rotatably holds the 181 with respect to the casing 122b. The inner member 181 and the outer member 182 constitute a double-row angular ball bearing, and a double-row rolling element 183 is installed between the inner member 181 and the outer member 182. The inward member 181 is integrally provided with a wheel mounting flange portion 184.

JP 2012-97903 A

  Incidentally, the output shaft support bearing 190 that rotatably supports the output shaft 133 and the stabilizer 133d with respect to the outer pin housing 150 is disposed at a position facing both end surfaces of the inner pin 137 in the axial direction.

  Therefore, as shown in FIG. 9, the flange 133 a and the stabilizer 133 d of the output shaft 133 are provided with a stepped portion 133 e so as to face the pair of flanges 151 in order to support the output shaft support bearing 190. It is necessary to provide it protruding in the direction.

  For this reason, the axial direction length of the reduction gear B becomes long, and the full width of the in-wheel motor drive device 121 becomes large.

  When the entire width of the in-wheel motor drive device 121 is increased, there arises a problem that forced changes are required to peripheral components such as a suspension when the vehicle is mounted on a vehicle.

  Further, as the overall width of the in-wheel motor driving device 121 increases, the weight of the entire device increases accordingly, which is not preferable for the in-wheel motor driving device 121 that requires a reduction in unsprung load.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the width of the in-wheel motor drive device by devising the arrangement of the output shaft support bearing of the reduction gear.

  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 hub that transmits the output from the speed reducer to the drive wheels. An input shaft that is rotationally driven by the motor unit, a curved plate that is rotatably supported on the input shaft by an eccentric shaft portion provided on the input shaft, and has a corrugated tooth profile formed on the outer periphery; An outer pin that meshes with the corrugated tooth profile on the outer periphery of the curved plate, and a cylindrical outer pin that is provided in a state of being prevented from rotating on the inner diameter surface of the casing of the speed reducer and that has flange portions that support both end portions of the outer pin on both end surfaces A curved plate is incorporated in the outer pin housing, and the curved plate is eccentrically oscillated by rotation of the input shaft, and rotation of the curved plate is performed from an output shaft arranged coaxially with the input shaft. Output In the in-wheel motor drive device that is an Icroid type speed reducer, the output shaft has a flange portion and a shaft portion, and the flange portion of the output shaft has a circumference around the rotation axis of the output shaft. Inner pins are fixed on the top at equal intervals, a wheel hub is provided on the outer diameter surface of the shaft portion of the output shaft so that torque can be transmitted, and the flange portion of the output shaft and the stabilizer are connected via a plurality of inner pins. The output shaft and the stabilizer rotate together, and the flange portion and stabilizer of the output shaft are rotatably supported on the inner periphery of the flange portion of the outer pin housing via the output shaft support bearing. It is arranged on the outer diameter side of both ends of the pin.

  The wheel hub includes an inner member fixedly connected to the outer diameter surface of the shaft portion of the output shaft, and an outer member that rotatably holds the inner member with respect to the casing. The member constitutes a double-row angular contact ball bearing, a double-row rolling element is installed between the inner member and the outer member, and the inner ring raceway on the outboard side is the inner ring raceway of the inner row double-row inner raceway. It is possible to use one in which the inner ring member is formed integrally with the inner member, the inner ring raceway on the inboard side is formed in a separate inner ring member, and the double row outer ring raceway is integrally formed on the inner diameter surface of the outer member.

  Further, the double row inner ring raceway of the inner member and the double row outer ring raceway of the outer member are configured such that the PCD of the rolling element arranged on the outboard side is more than the PCD of the rolling element arranged on the inboard side. By providing the diameter so as to increase, the rolling element can be reduced in diameter and the load capacity can be ensured by increasing the number of the rolling elements, so that the axial dimension can be further shortened.

  Further, by increasing the thickness of the inner member in the radial direction, the axial dimension can be further shortened by improving the rigidity and load capacity of the wheel hub.

  In the in-wheel motor drive device according to the present invention, as described above, when the output shaft support bearings are arranged on the outer diameter sides of the both ends of the inner pin, the PCD of the output shaft support bearing causes the output shaft support bearing to move to the inner pin. Because it becomes larger than the conventional one that was placed on the side of both ends of the shaft, the axial width is reduced by reducing the size of the rolling element and increasing the number of rolling elements even when securing equivalent load capacity It becomes possible to do.

It is a vertical front view of the in-wheel motor drive device concerning this invention. It is an expansion vertical front view of a reduction gear. It is a vertical side view along the DD line of FIG. It is an enlarged view of an oil pump. It is a vertical front view of other embodiment of the in-wheel motor drive device which concerns on this invention. It is a vertical front view of other embodiment of the in-wheel motor drive device which concerns on this invention. 1 is a schematic plan view of an electric vehicle having an in-wheel motor drive device according to the present invention. It is the figure which looked at the electric vehicle of FIG. 7 from back. It is a vertical front view which shows a prior art example. It is an expansion vertical front view of the reduction gear of a prior art example. It is a vertical side view along the DD line of FIG. It is a perspective view of the conventional outer pin housing. It is a longitudinal cross-sectional view of the conventional outer pin housing.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 7, an electric vehicle 11 including an in-wheel motor drive device according to an embodiment of the present invention includes a chassis 12, front wheels 13 as steering wheels, drive wheels (rear wheels) 14, left and right And an in-wheel motor drive device 21 that transmits a drive force to each of the drive wheels 14. As shown in FIG. 8, the drive wheel 14 is accommodated in a wheel housing 12a of the chassis 12, and is fixed to the lower portion of the chassis 12 via a suspension device (suspension) 12b. As a mounting form of the in-wheel motor drive device 21, in addition to the rear wheel drive system shown in FIGS. 7 and 8, either the front wheel drive system or the four wheel drive system may be used.

  The suspension device 12b supports the drive wheel 14 by a suspension arm that extends to the left and right, and suppresses vibration of the chassis 12 by absorbing vibration received by the drive wheel 14 from the ground by a strut including a coil spring and a shock absorber. Furthermore, a stabilizer that suppresses the inclination of the vehicle body when turning or the like is provided at a connecting portion of the left and right suspension arms. The suspension device 12b is an independent suspension type in which the left and right wheels can be moved up and down independently in order to improve the followability to the road surface unevenness and efficiently transmit the driving force of the driving wheels to the road surface. Is desirable.

  The electric vehicle 11 needs to be provided with a motor, a drive shaft, a differential gear mechanism, and the like on the chassis 12 by providing an in-wheel motor drive device 21 that drives the left and right drive wheels 14 inside the wheel housing 12a. This eliminates the need to secure a wide cabin space and control the rotation of the left and right drive wheels.

  As shown in FIG. 1, the in-wheel motor drive device 21 includes a motor unit A that generates a driving force, a speed reducer B that decelerates and outputs the rotation of the motor unit A, and an output from the speed reducer B as driving wheels. The motor hub A and the speed reducer B are housed in the casing 22 and are mounted in the wheel housing 12a of the electric vehicle 11 as shown in FIG.

  The motor part A and the speed reducer B are accommodated in the casing 22. The casing 22 includes a casing 22a on the motor part A side and a casing 22b on the reduction gear B side.

  The motor part A uses a radial gap type in which a stator 23 is provided on the inner peripheral surface of the casing 22a, and a rotor 24 is provided at an interval on the inner periphery of the stator 23.

  The rotor 24 has a motor shaft 24a at the center, and the motor shaft 24a is connected to the input shaft 30 of the speed reducer B and is inserted into the casing 22b of the speed reducer B. And is supported rotatably.

  The casing 22b of the speed reducer B 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 A and the speed reducing device B for lubrication. And cooling.

  The oil supply passage 43 that supplies lubricating oil to the inside of the speed reducer B extends along the inside of the casing 22a from the discharge port of the oil pump 42 that is driven by using the output rotation of the speed reducer B that decelerates the rotation of the motor part A. The passage extends from the rear of the casing 22a through the internal passage 44 of the motor shaft 24a and the internal passage 45 of the input shaft 30 of the reduction gear B to the inside of the casing 22b of the reduction gear B. The lubricating oil supplied from the oil pump 42 is scattered by the centrifugal force and the pressure of the oil pump 42 from the radial supply port provided in the internal passage 45 of the input shaft 30 of the speed reducer B, and the speed reducer B The inside is lubricated and cooled. A so-called axial center lubrication system is adopted.

  The return passage 46 for the lubricating oil is constituted by a discharge port 47 provided at the bottom of the casing 22 b of the speed reducer B and a passage that reaches the suction port of the oil pump 42 through the oil tank 41.

  As shown in FIG. 4, the oil pump 42 includes an inner rotor 72 that rotates using the rotation of the speed reducer B, an outer rotor 73 that rotates following the rotation of the inner rotor 72, a pump chamber 74, and a feedback The cycloid pump includes a suction port 75 penetrating the passage 46 and a discharge port 76 penetrating the oil supply passage 43.

  Inner rotor 72 has a tooth profile formed of a cycloid curve on the outer diameter surface. Specifically, the shape of the tooth tip portion 72a is an epicycloid curve, and the shape of the tooth gap portion 72b is a hypocycloid curve. The inner rotor 72 rotates integrally with the output shaft 33 of the speed reducer B.

  The outer rotor 73 has a tooth profile formed of a cycloid curve on the inner diameter surface. Specifically, the shape of the tooth tip portion 73a is a hypocycloid curve, and the shape of the tooth gap portion 73b is an epicycloid curve. The outer rotor 73 is rotatably supported by the pump case 77.

  The inner rotor 72 rotates around the rotation center c1. On the other hand, the outer rotor 73 rotates around a rotation center c2 different from the rotation center c1 of the inner rotor 72. Further, when the number of teeth of the inner rotor 72 is n, the number of teeth of the outer rotor 73 is (n + 1). In this embodiment, n = 5.

  A plurality of pump chambers 74 are provided in the space between the inner rotor 72 and the outer rotor 73. When the inner rotor 72 rotates using the rotation of the output shaft 33 of the speed reducer B, the outer rotor 73 rotates in a driven manner. At this time, since the inner rotor 72 and the outer rotor 73 rotate about different rotation centers c1 and c2, respectively, the volume of the pump chamber 74 changes continuously. As a result, the lubricating oil flowing in from the suction port 75 is pumped from the discharge port 76 to the oil supply passage 43.

  As shown in FIG. 1, the casing 22 b of the speed reducer B 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 through the return passage 46, and the motor unit A Lubricating oil is supplied to the reduction gear B to perform lubrication and cooling.

  As shown in FIGS. 1 to 3, the cycloid type speed reducer B rotatably supports two curved plates 31 by eccentric shaft portions 30 a and 30 b provided on the input shaft 30, and these curved plates 31. The corrugated tooth profile 31a formed on the outer periphery of the gear plate is engaged with the outer pin 32 disposed inside the casing 22b of the speed reducer B, and the curved plate 31 is caused to eccentrically swing by the rotation of the input shaft 30. The rotation of 31 is output from the output shaft 33 arranged coaxially with the input shaft 30, and the wheel hub C is rotated.

  The number of outer pins 32 disposed inside the casing 22 b of the reduction gear B is larger than the corrugated tooth profile 31 a on the outer periphery of the curved plate 31.

  As shown in FIG. 1, the outer pin 32 is supported by an outer pin housing 50 that is disposed on the inner diameter surface of the casing 22 b of the speed reducer B via a gap. The outer pin housing 50 is floatingly supported by floating bolts (not shown) on the outer side and the inner side with respect to the casing 22b of the speed reducer B.

  The outer pin housing 50 has a cylindrical shape, and includes a pair of flange portions 51 extending toward the inner diameter side at both axial ends as shown in FIG.

  As shown in FIG. 1, one end of the input shaft 30 is connected to the motor shaft 24a of the rotor 24 by spline fitting and is driven to rotate by the motor portion A. The other end is an eccentric shaft. Portions 30a and 30b are provided.

  As shown in FIG. 2, a pair of eccentric shaft portions 30 a and 30 b are provided in the axial direction of the input shaft 30. The pair of eccentric shaft portions 30a and 30b is provided such that the center of the cylindrical outer diameter surface is 180 degrees out of phase in the circumferential direction, and rolls to the outer diameter surface of each of the pair of eccentric shaft portions 30a and 30b. A bearing 34 is fitted.

  The input shaft 30 provided with the pair of eccentric shaft portions 30a and 30b is provided with a pair of counterweights 35 with a 180 ° phase shift in the circumferential direction so as to sandwich the pair of eccentric shaft portions 30a and 30b.

  The curved plate 31 is rotatably supported on the input shaft 30 by the rolling bearing 34, and the corrugated tooth profile 31a formed on the outer periphery thereof is a trochoidal curved tooth profile. As shown in FIG. 3, the curved plate 31 has a plurality of pin holes 36 formed at equal intervals on a single circle centered on the rotation axis, and each of the pair of pin holes 36 aligned in the axial direction is formed in each of the pair of pin holes 36. A pin 37 is inserted with a margin, and an outer peripheral part of an inner pin bearing 37 a rotatably supported by the inner pin 37 is in contact with an inner peripheral part of the pin hole 36.

  As shown in FIGS. 1 and 2, two inner pin bearings 37a abut against the pin hole 36 of the curved plate 31, respectively. Be placed. Spacers 37c and 37d for determining the axial position of the inner pin bearing 37a are also provided on the flange 33a side and the stabilizer 33d side of the output shaft 33 of the two inner pin bearings 37a. The common spacer 37b and the spacers 37c and 37d have a function of restricting movement of the inner pin bearing 37a in the axial direction and a function of preventing the needle roller of the inner pin bearing 37a from falling off.

  As shown in FIG. 2, the speed reducer B includes two curved plates 31 as revolving members that are rotatably held by the eccentric shaft portions 30a and 30b, and a corrugated tooth profile 31a on the outer peripheral portion of the curved plate 31 (FIG. 3). A plurality of outer pins 32 that engage with each other, an output shaft 33 that outputs the rotational movement of the curved plate 31, and a curved surface that is attached to the gap between the two curved plates 31 and abuts against the end surfaces of these curved plates 31. And a center collar 38 for preventing the plate from tilting.

  The output shaft 33 has a flange portion 33a and a shaft portion 33b. As shown in FIG. 3, inner pins 37 are fixed to the flange portion 33 a at equal intervals on a circumference centered on the rotation axis of the output shaft 33. As shown in FIG. 1, a wheel hub C is provided on the outer diameter surface of the shaft portion 33b so that torque can be transmitted by serrations (or splines). The flange portion 33a and the stabilizer 33d are connected via the plurality of inner pins 37, and the output shaft 33 and the stabilizer 33d rotate integrally. A pump drive shaft 33c connected to the inner rotor 72 of the oil pump 42 is integrally provided at the end of the stabilizer 33d on the motor part A side.

  The outer pins 32 are provided at equal intervals on the circumferential track of the rotation axis of the input shaft 30. When the curved plate 31 revolves, the outer peripheral corrugated tooth profile 31a and the outer pin 32 engage with each other, causing the curved plate 31 to rotate.

  As shown in FIG. 2, the flange portion 33 a of the output shaft 33 and the stabilizer 33 d are rotatably supported on the inner periphery of the flange portion 51 of the outer pin housing 50 via an output shaft support bearing 90. Further, the inner diameter surface of the flange portion 33 a and the stabilizer 33 d of the output shaft 33 and the outer diameter surface of the input shaft 30 are supported through a rolling bearing 91 so as to be relatively rotatable.

  The output shaft support bearing 90 that rotatably supports the outer peripheral surfaces of the flange portion 33 a and the stabilizer 33 d of the output shaft 33 on the inner peripheral surface of the flange portion 51 of the outer pin housing 50 is positioned at the outer diameter positions of both end portions of the inner pin 37. It is arranged.

  By disposing the output shaft support bearings 90 at the outer diameter positions of both end portions of the inner pin 37, the axial direction of the flange portion 33a of the output shaft 33 and the stabilizer 33d is larger than when disposed on both sides of the inner pin 37 in the axial direction. Can be narrowed.

  Further, by arranging the output shaft support bearing 90 at the outer diameter positions at both ends of the inner pin 37, the PCD of the output shaft support bearing 90 is increased and the load capacity is improved, so that the diameter of the rolling element can be reduced. The weight of the apparatus can be reduced.

  The curved plate 31 is incorporated between the flange portion 33a and the stabilizer 33d facing the output shaft 33. Further, both ends of the inner pin 37 penetrating the pin hole 36 of the incorporated curved plate 31 are supported by the opposing flange portion 33a and the stabilizer 33d of the output shaft 33.

  The plurality of inner pins 37 supported by the flange portion 33 a and the stabilizer 33 d that face the output shaft 33 are provided at equal intervals on a circumferential track centering on the rotational axis of the input shaft 30, and friction with the curved plate 31. In order to reduce the resistance, an inner pin bearing 37a made of a needle roller bearing is provided at a position where it abuts against the inner wall surface of each pin hole 36 of the two curved plates 31. The inner diameter dimension of the pin hole 36 is set to be larger by a predetermined amount than the outer diameter dimension of the inner pin 37 (referred to as “maximum outer diameter including the inner pin bearing 37a”, hereinafter the same).

  From the viewpoint of reducing the weight of the in-wheel motor drive device 21, the casing 22 is 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 steel.

  As shown in FIG. 2, the pair of flange portions 51 of the outer pin housing 50 is provided with a plurality of outer pin holding holes 54 penetrating in the thickness direction. The outer pin holding holes 54 extend in a direction parallel to the rotation axis of the input shaft 30 and hold both ends of the outer pin 32. Both ends of the outer pin 32 are supported by the outer pin holding hole 54 via needle roller bearings 55. The needle roller bearing 55 includes an outer ring 55a and needle rollers 55b having an inner peripheral surface of the outer ring 55a and an outer peripheral surface of the outer pin 32 as rolling surfaces. The outer ring 55 a of the needle roller bearing 55 is fitted into the inner surface of the outer pin holding hole 54.

  Further, the corresponding outer pin holding holes 54 of the pair of flange portions 51 are provided so as to face each other at the same position in the circumferential direction. That is, the center axes of the pair of outer pin holding holes 54 coincide with each other, and when the outer pin housing 50 is attached to the casing 22 b of the reduction gear B, the center axis of the outer pin holding holes 54 is parallel to the rotation axis of the input shaft 30. become. Thereby, the outer pin 32 can be held in parallel with the rotation axis of the input shaft 30.

  As shown in FIG. 2, an outer pin side plate 58 that prevents the outer pin 32 inserted into the outer pin holding hole 54 from coming out in the axial direction is formed on the outer surface portion located on the outer peripheral side in the radial direction of the pair of flange portions 51. Are fixed respectively.

  As shown in FIG. 1, the wheel hub C includes an inner member 81 fixedly connected to the outer diameter surface of the shaft portion 33b of the output shaft 33, and an outer member that rotatably holds the inner member 81 with respect to the casing 22b. And a direction member 82. The inner member 81 and the outer member 82 constitute a double-row angular ball bearing, and double-row rolling elements 83 a and 83 b are installed between the inner member 81 and the outer member 82.

  Out of the double row inner ring raceways of the inner member 81, the inner ring track on the outboard side is formed integrally with the inner member 81, the inner ring raceway on the inboard side is formed on the separate inner ring member 84, and Although the outer ring raceway in a row is formed integrally with the inner diameter surface of the outer member 82, the so-called third generation one is shown, but the first generation and the second generation may be used.

  A wheel mounting flange 85 is formed integrally with the inner member 81, and a brake rotor and a wheel (not shown) are mounted on the wheel mounting flange 85 with bolts 86.

  Between the inner member 81 and the outer member 82, grease is filled, and in order to prevent the grease from leaking and to prevent intrusion of muddy water or the like, both sides of the double row rolling elements 83a and 83b are provided. Seal members 87a and 87b are provided.

  Next, in the embodiment shown in FIG. 5, the double-row inner ring raceway of the inner member 81 and the double-row outer ring raceway of the outer member 82 are obtained by replacing the PCD of the rolling elements 83 b arranged on the inboard side with the outboard. The rolling element 83a disposed on the side is provided with a diameter larger than that of the PCD.

  Since the rigidity and load capacity of the wheel hub C can be improved by increasing the PCD of the rolling elements 83b arranged on the inboard side, it is possible to reduce the distance between the double-row rolling elements 83a and 83b. It becomes. Therefore, the embodiment shown in FIG. 5 can further reduce the axial length compared to the embodiment shown in FIG.

  Next, in the embodiment shown in FIG. 6, by increasing the thickness of the inner member 81 in the radial direction, the rigidity and load capacity of the wheel hub C are improved, and the interval between the double row rolling elements 83a and 83b is increased. It is narrowed. Accordingly, the axial length of the embodiment shown in FIG. 6 can be made even narrower than that of the embodiment shown in FIG.

  In the above-described embodiment, an example of a cylindrical roller bearing has been shown as the rolling bearing 34 that supports the curved plate 31. However, the present invention is not limited to this example. For example, a plain bearing, a deep groove ball bearing, a tapered roller bearing, and a needle roller Bearings, spherical roller bearings, angular contact ball bearings, 4-point contact ball bearings, etc., whether they are plain bearings or rolling bearings, regardless of whether the rolling elements are rollers or balls, All bearings can be applied, whether double row or single row. Similarly, any type of bearing can be adopted for bearings arranged in other locations.

  Moreover, in the said embodiment, the radial gap provided with the stator 23 fixed to the casing 22a in the motor part A, and the rotor 24 arrange | positioned in the position which faces the inner side of the stator 23 with a radial gap. Although the example which employ | adopted the motor was shown, the motor of arbitrary structures is applicable, without restricting to this. 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 in-wheel motor drive device 21 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. Moreover, in the in-wheel motor drive device 21 which concerns on this invention, although the example which employ | adopted the cycloid type reduction gear was shown, it applies not only to this but a 2-axis parallel reduction gear, a planetary reduction gear, and other reduction gears Is possible.

11: Electric vehicle 12: Chassis 12a: Wheel housing 12b: Suspension device 13: Front wheel 14: Drive wheel 21: In-wheel motor drive device 22: Casing 22a: Casing 22b: Casing 23: Stator 24: Rotor 24a: Motor shaft 25a: Bearing 25b: Bearing 30: Input shaft 30a: Eccentric shaft portion 30b: Eccentric shaft portion 31: Curved plate 31a: Corrugated tooth profile 32: Outer pin 33: Output shaft 33a: Flange portion 33b: Shaft portion 33c: Pump drive shaft 33d: Stabilizer 34: Rolling bearing 35: Counter weight 36: Pin hole 37: Inner pin 37a: Inner pin bearing 37b: Common spacer 37c: Spacer 37d: Spacer 38: Center collar 41: Oil tank 42: Oil pump 43: Oil supply passage 44: Inner Passage 45: Internal passage 46: Return passage 47: Discharge port 50: Outer pin housing 51: Flange portion 54: Outer pin holding hole 55: Bearing 55a: Outer ring 55b: Needle roller 58: Outer pin side plate 72: Inner rotor 72a: Tooth tip portion 72b : Tooth gap portion 73: outer rotor 73a: tooth tip portion 73b: tooth groove portion 74: pump chamber 75: suction port 76: discharge port 77: pump case 81: inner member 82: outer member 83a: rolling element 83b: Rolling element 84: Inner ring member 85: Wheel mounting flange 86: Bolt 87a: Seal member 87b: Seal member 90: Output shaft support bearing 91: Rolling bearing A: Motor part B: Reducer C: Wheel hub c1: Wheel center c2: Rotation center

Claims (4)

  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 that transmits the output from the speed reducer to a drive wheel, and the speed reducer is rotationally driven by the motor unit. An input shaft, a curved plate that is rotatably supported by the input shaft by an eccentric shaft portion provided on the input shaft, and has a corrugated tooth profile formed on the outer periphery, and an outer pin that meshes with the corrugated tooth profile on the outer periphery of the curved plate, A cylindrical outer pin housing that is provided in a state of being prevented from rotating on the inner diameter surface of the casing of the speed reducer and has flange portions that support both end portions of the outer pin at both end surfaces, and a curved plate in the outer pin housing The cycloid-type speed reducer is configured such that the curved plate is eccentrically oscillated by the rotation of the input shaft, and the rotation of the curved plate is output from the output shaft arranged coaxially with the input shaft. In-wheel mode In the drive device, the output shaft has a flange portion and a shaft portion, and inner pins are fixed to the flange portion of the output shaft at equal intervals on a circumference around the rotation axis of the output shaft, A wheel hub is provided on the outer diameter surface of the shaft portion of the output shaft so that torque can be transmitted, and the flange portion of the output shaft and the stabilizer are connected via a plurality of inner pins so that the output shaft and the stabilizer rotate integrally, On the inner periphery of the pin housing flange, the output shaft flange and stabilizer are rotatably supported via the output shaft support bearings. These output shaft support bearings are arranged on the outer diameter side of both ends of the inner pin. An in-wheel motor drive device characterized by that.   The wheel hub includes an inner member fixedly connected to the outer diameter surface of the shaft portion of the output shaft, and an outer member that rotatably holds the inner member with respect to the casing. The member constitutes a double-row angular contact ball bearing, a double-row rolling element is installed between the inner member and the outer member, and the inner ring raceway on the outboard side is the inner ring raceway of the inner row double-row inner raceway. The inner ring raceway is formed integrally with the inner member, the inner ring raceway on the inboard side is formed as a separate inner ring member, and the double row outer ring raceway is formed integrally with the inner diameter surface of the outer member. The in-wheel motor drive device according to 1.   The inner row raceway of the inner member and the outer race raceway of the outer member have a diameter larger than the PCD of the rolling element arranged on the outboard side. The in-wheel motor drive device according to claim 2, wherein the in-wheel motor drive device is provided to be large.   The in-wheel motor drive device according to claim 2, wherein the rigidity and load capacity of the wheel hub are improved by increasing the thickness of the inward member in the radial direction.

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