JP2005308111A - Driving device of motor-driven vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a hub reduction gear and to simplify a structure thereof by changing a part of the structure of the hub reduction gear. <P>SOLUTION: A driving device 1 of a vehicle having an output shaft 5 and a driving wheel 4 comprises a sun gear 5a provided on an outer circumferential part of the output shaft 5, a plurality of pinion gears 10 spline-engaged with the sun gear 5a, an annular ring gear 40 spline-engaged with the plurality of pinion gears 10, a carrier 30 which supports the plurality of pinion gear 10 while the driving wheel 4 is fixed to the outer circumferential part thereof, and a pinion bearing 20 to support the pinion gear 10 by the carrier 30 in a relatively rotational manner. The pinion bearing 20 is arranged on the side in the axial direction of the pinion gear 10. The pinion bearing 20 is arranged only in one side of the axial direction of the pinion gear 10, and the pinion bearing 20 is arranged on the side opposite to the output shaft 5 with respect to the sun gear 5a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hub speed reducer in a vehicle drive device.

  Conventionally, it has been common to use an internal combustion engine as a power source of a vehicle, but in recent years, with the close-up of environmental problems, electric vehicles with less air pollution and noise due to exhaust gas have begun to attract attention. . Since an electric vehicle uses a motor that rotates by electric power as a power source, exhaust gas is not discharged and noise is smaller than that of an internal combustion engine. Therefore, not only for automobiles but also for fields such as forklifts where both internal combustion engines and electric motors have been used as drive devices, the proportion of electric motors used for the purpose of improving the working environment is increasing year by year. Yes.

  The power generated in these power sources is finally transmitted to the drive wheels via a power transmission mechanism or the like and used for traveling of the vehicle. In that case, the vehicle repeatedly starts and stops during use, such as starting from a stopped state and stopping from a traveling state. Depending on the slope of the place where the vehicle travels, a larger torque is required when starting the vehicle than when traveling. In addition, when it is necessary to change the speed during traveling, it is necessary to change the speed of the power source for transmission. Therefore, a reduction gear is generally provided in the power transmission path from the power source to the drive wheels for the purpose of increasing torque and shifting.

  As a vehicle deceleration device, for example, a transmission, a differential device, and the like are employed in an automobile. The transmission is a device that changes the rotation of the crankshaft of the engine in several stages. Since the required torque becomes large when the vehicle starts, the torque is increased while the rotation is decelerated by the gears, and the necessary torque is ensured when starting. The differential device is for decelerating while absorbing the difference in rotation between the left and right drive wheels that occurs when the vehicle turns. Similarly, a motor-driven vehicle such as a forklift is provided with a reduction gear, a differential, and the like.

  Usually, since the reduction gear and the differential gear have a plurality of gears inside the electric motor, the device itself tends to be large. Therefore, in order to reduce the installation space of the speed reducer, a hub speed reducer is known in which a planetary gear type is adopted as the speed reducer and the speed reducer is embedded around the wheel hub of the drive wheel.

An example of the hub speed reducer is described in Patent Document 1. In this hub speed reducer, a ring gear is fixed to the end of the output shaft, and the sun gear and the drive wheel are rotated via a plurality of pinion gears and carriers.
Japanese Utility Model Publication No. 4-3147

  As in Patent Document 1, a conventional hub speed reducer is provided with a bearing inside a pinion gear, and a pin is inserted and supported by a carrier. In this structure, since the bearing is provided inside the pinion gear, it is difficult to reduce the diameter of the pinion gear. In addition, since the carrier supports a plurality of pinion gears at both ends in the axial direction, the structure of the carrier is complicated and it is difficult to process the member.

  An object of the present invention is to change the structure of a part of the hub speed reducer, thereby enabling downsizing of the hub speed reducer and simplifying the structure.

  A hub speed reducer according to a first aspect of the present invention is a vehicle drive device including an output shaft and drive wheels, and transmits the rotation of the output shaft to the drive wheels while decelerating the rotation. Supports a sun gear provided on the outer periphery of the output shaft, a plurality of pinion gears that are spline engaged with the sun gear, an annular ring gear that is spline engaged with the plurality of pinion gears, and a plurality of pinion gears, and a driving wheel is fixed to the outer periphery And a pinion bearing that supports the pinion gear so as to be rotatable relative to the carrier. The pinion bearing is disposed on the axial direction side of the pinion gear.

  In this hub speed reducer, since the pinion bearing is arranged on the side of the pinion gear in the axial direction, it is not necessary to provide the pinion bearing inside the pinion gear, and the pinion gear can be reduced in diameter. Therefore, the hub speed reducer itself can be downsized.

  According to a second aspect of the present invention, in the hub speed reducer according to the first aspect, the pinion bearing is disposed only in one of the axial directions of the pinion gear.

  In this hub speed reducer, the pinion bearing is disposed only on one side of the pinion gear in the axial direction. Therefore, compared to the case where the pinion bearings are provided at both ends of the pinion gear in the axial direction, the carrier supporting the plurality of pinion gears. The structure can be simplified.

  According to a third aspect of the present invention, in the hub speed reducer according to the second aspect, the pinion bearing is disposed on the opposite side to the output shaft with respect to the sun gear.

  In this hub speed reducer, since the pinion bearing is disposed on the opposite side of the output shaft with respect to the sun gear, the pinion bearing and the carrier are disposed on the outer side in the width direction of the vehicle, and the carrier is easily disposed. .

  According to a fourth aspect of the present invention, in the first to third aspects, the pinion gear includes a first part and a second part. The first part is a part where the sun gear and the ring gear are spline-engaged. The second part is a part into which the pinion bearing is inserted.

  In this hub speed reducer, since the pinion gear has the second part to be inserted into the pinion bearing, the pinion gear can be securely inserted into the pinion bearing.

  According to a fifth aspect of the present invention, in the hub speed reducer according to the fifth aspect, the pinion gear has a first axial surface between which the pinion bearing abuts in the axial direction between the first portion and the second portion.

  In this hub speed reducer, since the pinion gear has the first axial surface, when the pinion bearing is inserted into the pinion gear, the axial position of the pinion bearing with respect to the pinion gear is determined, and the position of the pinion bearing is stabilized. .

  A hub speed reducer according to a sixth aspect of the present invention is the hub speed reducer according to the fourth or fifth aspect, wherein the pinion gear is attached to the bolt portion on the side opposite to the first portion of the second portion, and the pinion bearing is the second portion. And a drop-off preventing member for preventing the drop-off from falling off.

  In this hub speed reducer, since the pinion gear has the drop-off preventing member, the pinion bearing can be fixed to the pinion gear, and the pinion bearing can be prevented from dropping off from the pinion gear.

  According to a seventh aspect of the present invention, in the hub speed reducer according to any one of the first to sixth aspects, the carrier has an accommodating portion to which a pinion bearing is attached and for accommodating at least a part of the pinion gear.

  In this hub speed reducer, since the carrier has an accommodating portion, a pinion bearing can be attached, and the pinion gear and the carrier can be coupled so as to be relatively rotatable.

  According to an eighth aspect of the present invention, in the hub speed reducer according to the seventh aspect, the accommodating portion has a second axial surface that abuts the pinion bearing in the axial direction.

  In this hub speed reducer, since the housing portion has the second axial surface, the axial position of the pinion bearing with respect to the carrier is determined, the position of the pinion bearing is stabilized, and the rotation of the carrier is also stabilized.

  According to a ninth aspect of the present invention, in the hub speed reducer according to the seventh or eighth aspect, the accommodating portion has a movement preventing member. The movement preventing member is for preventing axial movement of the pinion bearing with respect to the carrier.

  In this hub speed reducer, since the housing portion has the movement preventing member, it is possible to prevent the pinion bearing from falling off the carrier.

  If it is a hub reduction gear which concerns on this invention, size reduction of a hub reduction gear and simplification of a structure will be attained by changing a part of structure.

Embodiments of the present invention will be described below with reference to the drawings.
(1) Structure of Drive Device FIG. 1 shows an example of a drive device 1 that employs a hub speed reducer according to the present invention. In the present embodiment, a case where an electric motor is employed as a power source will be described. The drive device 1 includes a power generation mechanism 2 for driving a vehicle, a pair of shaft support mechanisms 3, a pair of drive wheels 4, and a hub speed reducer 7. The power generation mechanism 2 includes an electric motor (not shown) as a power source, a differential (not shown), and an output shaft 5, which are accommodated by a housing 6. The shaft support mechanism 3 is disposed on the left and right sides of the housing 6, and the output shaft 5 passes through the inside. Drive wheels 4 and a hub speed reducer 7 are disposed at the distal ends of the shaft support mechanism 3 and the output shaft 5.

(2) Structure of shaft support mechanism FIG. 2 is a sectional view of the periphery of the shaft support mechanism. The shaft support mechanism 3 is for rotatably supporting the drive wheel 4, a hub speed reducer 7 and a drive wheel 4 described later, and mainly includes an axle tube 60, a brake 50, and a bearing portion 70. Is done. The axle tube 60 is for rotatably supporting the output shaft 5, the drive wheel 4, and the like, and one end is fixed to the housing 6. The axle tube 60 is a cylindrical member, and the output shaft 5 penetrates the inside thereof. The output shaft 5 is rotatably supported with respect to the axle tube 60 by a bearing (not shown) provided on the inner peripheral side of the axle tube 60. The brake 50 is for suppressing the rotation of the drive wheel 4, and the brake hub 51 constitutes a part thereof. The brake hub 51 is an annular member disposed on the outer peripheral side of the axle tube 60. The bearing portion 70 is disposed between the axle tube 60 and the brake hub 51, and supports the brake hub 51 rotatably with respect to the axle tube 60. The bearing portion 70 also has a function of restricting the movement of the brake hub 51 in the axial direction with respect to the axle tube 60, and includes a first bearing 71 and a second bearing 72. As the first and second bearings 71 and 72, for example, two tapered roller bearings arranged in parallel in the axial direction can be considered. In FIG. 2, the first bearing 71 restricts movement of the brake hub 51 toward the axial carrier 30, and the second bearing 72 restricts movement of the brake hub 51 toward the axial brake 50.

  In the shaft support mechanism 3 described above, the hub speed reducer 7 for reducing the rotation of the output shaft 5 is connected to the end portions of the axle tube 60 and the output shaft 5.

(3) Structure around the hub speed reducer FIG. 3 shows a structure around the hub speed reducer according to the present invention, and FIG. 4 shows a cross-sectional view taken along the line AA in FIG. The hub speed reducer 7 adopts a planetary gear type, and mainly includes a sun gear 5 a, a pinion gear 10, a ring gear 40, a carrier 30, and a pinion bearing 20.

  The sun gear 5 a is a spline portion formed on the outer peripheral side of the end portion of the output shaft 5. A plurality of pinion gears 10 are arranged on the outer peripheral side of the sun gear 5a, and the pinion gears 10 are spline-engaged with the sun gear 5a without being in contact with each other. The present embodiment is constituted by three pinion gears 10.

  The ring gear 40 is disposed on the outer peripheral side of the plurality of pinion gears 10 and is spline-engaged with each pinion gear 10. The carrier 30 supports the end of each pinion gear 10 so as to be relatively rotatable. Details of the structure of each member will be described below.

1) Structure of Pinion Gear The pinion gear 10 is a cylindrical member, and mainly includes a first portion 11 having a large diameter, a second portion 13 having a small diameter, and a bolt portion 16. The first portion 11 is a portion that is spline-engaged with the sun gear 5a and the ring gear 40, and has the first spline portion 12 on the outer peripheral side. The second part 13 is a part into which a pinion bearing 20 described later is inserted, and is provided only on one side of the first part 11 in the axial direction. Since the second portion 13 has a smaller outer diameter than the first portion 11, a first axial surface 14 is formed at the joint between the second portion 13 and the first portion 11.

  The bolt part 16 is disposed on the opposite side of the second part 13 from the first part 11 and has an outer diameter smaller than that of the second part 13. The bolt portion 16 is screwed with a nut 15 for preventing the pinion bearing 20 from falling off the second portion 13. When the nut 15 is screwed into the bolt portion 16, the pinion bearing 20 is fixed to the pinion gear 10 in a state where the pinion bearing 20 is in contact with the first axial surface 14.

2) Pinion bearing The pinion bearing 20 is fitted into the second portion 13 of the pinion gear 10. The pinion bearing 20 is disposed on the opposite side of the output shaft 5 with respect to the sun gear 5a. In the present embodiment, two pinion bearings 20 are arranged in parallel in the axial direction. Each pinion bearing 20 includes an inner ring 21, an outer ring 22, and rollers 23.

  The inner ring 21 is an annular member disposed on the inner peripheral side of the pinion bearing 20, and is fixed to the second portion 13 in contact with the first axial surface 14 of the pinion gear 10. The outer ring 22 is an annular member disposed on the outer peripheral side of the pinion bearing 20 and is fixed to a first accommodating portion 33a described later. The rollers 23 are cylindrical members, and a plurality of rollers 23 are arranged between the inner ring 21 and the outer ring 22 in the circumferential direction.

3) Carrier structure The carrier 30 is mainly composed of a carrier portion 31 and a hub portion 32. The carrier portion 31 is a columnar member, and includes a storage portion 33, a second axial surface 35, a groove portion 36, a movement preventing member 37, and a thrust plate 38. The accommodating part 33 is a cylindrical cavity for accommodating a part of the pinion gear 10, and a plurality of accommodating parts 33 are formed on the surface of the carrier part 31 on the output shaft 5 side. The accommodating part 33 is further comprised from the 1st accommodating part 33a and the 2nd accommodating part 33b of the axial direction outer side from it. The 1st accommodating part 33a is a part which accommodates the 2nd part 13, and also the pinion bearing 20 is inserted, and the outer ring | wheel 22 of the pinion bearing 20 is being fixed. The second accommodating portion 33b is a portion in which the bolt portion 16 and the nut 15 of the pinion gear 10 are accommodated.

  The first accommodating portion 33a has a larger inner diameter than the second accommodating portion 33b, and a second axial surface 35 is formed between the accommodating portions 33a and 33b. When the pinion bearing 20 is inserted and fitted, the outer ring 22 abuts against the second axial surface 35, whereby the axial position of the pinion gear 10 with respect to the carrier 30 is determined.

  The groove portion 36 is formed on the inlet side of the first housing portion 33a over the entire circumference along the inner peripheral surface of the first housing portion 33a. The movement preventing member 37 is a ring-shaped member having a notch, such as a snap ring. Since the movement preventing member 37 has a notch, it can be elastically deformed radially inward to reduce the outer diameter. Therefore, the movement preventing member 37 can be mounted in the groove portion 36 by being elastically deformed to be smaller than the inner diameter of the first housing portion 33a. By mounting the movement preventing member 37 in the groove portion 36, it is possible to prevent the pinion bearing 20 from dropping from the carrier 30.

  The thrust plate 38 is for receiving a thrust force acting between the end portion of the output shaft 5 and the carrier portion 31, and is provided near the center of the carrier portion 31 between the end portion of the output shaft 5 and the carrier portion 31. ing.

  The hub portion 32 is an annular member formed on the outer peripheral side of the carrier portion 31, and the wheel 4a of the drive wheel 4 is fixed. The hub portion 32 is fixed to the end portion of the brake hub 51. Thereby, the carrier 30, the drive wheel 4, and the brake hub 51 rotate integrally, and the rotation can be suppressed by the brake 50.

  Summarizing the arrangement relationship of the above members, the carrier 30 is arranged on the outer side in the axial direction than the sun gear 5a and the first spline portion 11a (on the opposite side to the output shaft 5 with respect to the sun gear 5a). The second portion 13 of the pinion gear 10 extends axially outward from the first portion 11, is accommodated in the accommodating portion 33 of the carrier 30, and is rotatable on the inner peripheral surface of the accommodating portion 33 via the pinion bearing 20. It is supported by.

4) Structure of ring gear The ring gear 40 includes a ring portion 41 and a support portion 42. The ring portion 41 is an annular member, and a second spline portion 43 is provided on the inner peripheral side. The ring portion 41 is disposed on the outer peripheral side of the plurality of pinion gears 10 and is spline engaged with each pinion gear 10. The support part 42 is for supporting the ring part 41 with respect to the axle tube 60 and is an annular member.

  The support portion 42 is provided on one side of the ring portion 41 in the axial direction, and is fixed to the axle tube 60 so as not to be relatively rotatable. Specifically, the support portion 42 is spline-engaged with the outer peripheral side of the axle tube 60, and in order to prevent the ring gear 40 from moving toward the axial carrier 30 with respect to the axle tube 60, the end portion of the axle tube 60 is provided. Is provided with a fixing portion 61.

  A first bearing 71 is provided on the outer peripheral side of the support portion 42, and the first bearing 71 is in contact with the support portion 42 and the axial carrier 30 side. The first bearing 71 is in contact with the brake hub 51 and the axial brake 50 side. On the other hand, the second bearing 72 is in contact with the brake hub 51 and the axial carrier 30 side, and is in contact with the axle tube 60 and the axial brake 50 side. Therefore, the axial positions of the bearing portion 70 and the ring gear 40 are determined by pressing the support portion 42 toward the axial brake 50 side by the fixed portion 61.

(4) Operation of Hub Reducer The operation of the hub reducer 7 will be described. The rotation from the power source is transmitted to the output shaft 5 through a differential device or the like. When the sun gear 5a rotates together with the output shaft 5, the plurality of pinion gears 10 spline-engaged with the sun gear 5a rotate in the direction opposite to the rotation of the sun gear 5a. Each pinion gear 10 is spline-engaged with a ring gear 40 fixed to the axle tube 60. Therefore, each pinion gear 10 revolves around the output shaft 5 in the rotation direction of the sun gear 5a with respect to the ring gear 40 while rotating in the direction opposite to the rotation of the sun gear 5a.

  When each pinion gear 10 revolves, the carrier 30 and the drive wheel 4 also rotate through the pinion bearing 20. Therefore, since the rotational motion of the sun gear 5a is converted into the revolution motion of the pinion gear 10, the rotation of the output shaft 5 is transmitted to the drive wheels 4 in a decelerated state. In addition, since the brake hub 51 is fixed to the hub portion 32 of the carrier 30, when the rotation of the brake hub 51 is suppressed by the brake 50, the rotation of the drive wheels 4 and the carrier 30 is also suppressed.

  When a thrust force is applied to the drive wheels 4 while the vehicle is running, the thrust force is transmitted to the brake hub 51 and the carrier 30 via the hub portion 32. Since the wheel hub 51 is restricted from moving in the axial direction by the bearing portion 70, the movement in the axial direction of the drive wheels 4 and the carrier 30 is also restricted. Therefore, the carrier 30 does not fall off due to the thrust force acting on the drive wheels 4.

  When a thrust force is applied to the output shaft 5 from the power generation mechanism 2 side, the carrier 30 is restricted from moving in the axial direction as described above. Therefore, the axial movement of the output shaft 5 is also restricted by the thrust plate 38, the carrier 30, and the brake hub 51.

  The pinion bearing 20 is integrated with the carrier 30 in the axial direction by the first housing portion 33 a and the movement preventing member 37. The pinion bearing 20 is integral with the pinion gear 10 in the axial direction by a nut 15. Therefore, the pinion gear 10 supported by the carrier 30 does not fall off the carrier 30.

(5) Effects The effects of the present invention are summarized below.

  In the hub speed reducer 7 according to the present invention, since the pinion bearing 20 is disposed on the axial direction side of the pinion gear 10, it is not necessary to provide the pinion bearing 20 inside the pinion gear 10, and the pinion gear 10 can be reduced in diameter. Become. Therefore, the hub speed reducer 7 can be downsized. In addition, since the pinion bearing 20 is disposed only on one side of the pinion gear 10 in the axial direction, the carrier 30 that supports the plurality of pinion gears 10 as compared with the case where the pinion bearings are provided at both ends of the pinion gear 10 in the axial direction. The structure can be simplified.

  Since the pinion bearing 20 is arranged on the side opposite to the output shaft 5 with respect to the sun gear 5a, the pinion bearing 20 and the carrier 30 are arranged on the outer side in the width direction of the vehicle, and the arrangement of the carrier 30 is facilitated. . Further, since the pinion gear 10 has the second portion 13 to be inserted into the pinion bearing 20, the pinion gear 10 can be securely inserted into the pinion bearing 20.

  Since the pinion gear 10 has the first axial surface 14, when the pinion bearing 20 is inserted into the pinion gear 10, the axial position of the pinion bearing 20 with respect to the pinion gear 10 is determined, and the position of the pinion bearing 20 is stable. To do. Further, since the pinion gear 10 has the nut 15, it is possible to prevent the pinion bearing 20 from dropping from the pinion gear 10.

  Since the carrier 30 has the accommodating part 33, the pinion bearing 20 can be attached and the pinion gear 10 and the carrier 30 can be connected so that relative rotation is possible. Moreover, since the accommodating part 33 has the 2nd axial direction surface 35, the position of the axial direction of the pinion bearing 20 with respect to the carrier 30 is decided, the position of the pinion bearing 20 is stabilized, and rotation of the carrier 30 is also stabilized. Furthermore, since the accommodating part 33 has the movement prevention member 37, it can prevent that the pinion bearing 20 falls off from the carrier 30. FIG.

(5) Other Embodiments The present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the scope of the present invention.

1) Power Generation Mechanism In the above embodiment, the configuration of the power generation mechanism 2 is mainly an electric motor and a differential device. However, the configuration is not limited to this, and can be adopted in the case of various power generation mechanisms 2.

2) Pinion Gear In the above embodiment, three pinion gears 10 are arranged on the outer peripheral side of the sun gear 5a. However, the present invention is not limited to this.

3) Pinion bearing In the above-described embodiment, one pinion gear 10 is described in which two pinion bearings 20 are arranged in parallel in the axial direction. However, the present invention is not limited to this.

An example of the drive device which employ | adopted the hub reduction gear which concerns on this invention. Sectional drawing around a shaft support mechanism. Sectional drawing of the hub speed reducer periphery which concerns on this invention. AA sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drive device 2 Power generation mechanism 3 Shaft support mechanism 4 Drive wheel 5 Output shaft 5a Sun gear 7 Hub speed reducer 10 Pinion gear 20 Pinion bearing 30 Carrier 40 Ring gear 50 Brake 60 Axle tube 70 Bearing part

Claims (9)

In a vehicle drive device comprising an output shaft and drive wheels, a hub speed reducer for transmitting the rotation of the output shaft to the drive wheels while decelerating,
A sun gear provided on the outer periphery of the output shaft;
A plurality of pinion gears splined with the sun gear;
An annular ring gear spline-engaged with the plurality of pinion gears;
A carrier that supports the plurality of pinion gears, and the driving wheels are fixed to an outer peripheral portion;
A pinion bearing that rotatably supports the pinion gear on the carrier,
The pinion bearing is disposed on an axial side of the pinion gear,
Hub reducer. The pinion bearing is disposed only in one axial direction of the pinion gear,
The hub speed reducer according to claim 1. The pinion bearing is disposed on the opposite side of the output shaft with respect to the sun gear.
The hub speed reducer according to claim 2. The pinion gear has a first part in which the sun gear and the ring gear are spline-engaged, and a second part in which the pinion bearing is inserted,
The hub speed reducer in any one of Claim 1 to 3. The pinion gear has a first axial surface that is in axial contact with the pinion bearing between the first portion and the second portion.
The hub reducer according to claim 4. The pinion gear is attached to the bolt part, which is disposed on the opposite side of the second part to the first part, and is prevented from falling off to prevent the pinion bearing from falling off from the second part. Members,
Further having
The hub reducer according to claim 4 or 5. The carrier has an accommodating portion to which the pinion bearing is attached and accommodates at least a part of the pinion gear.
The hub reducer according to any one of claims 1 to 6. The accommodating portion has a second axial surface that is in axial contact with the pinion bearing.
The hub speed reducer according to claim 7. The housing portion includes a movement preventing member for preventing movement of the pinion bearing in the axial direction with respect to the carrier.
The hub reducer according to claim 7 or 8.