JP2008279850A - Drive device of vehicular driving wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive device D including a driving mechanism having an output shaft 10c and an electric motor 10a, in which the output shaft 10c is coupled with a rotary shaft 32 of each driving wheel through a constant speed universal joint J and the driving wheels W are rotated by operating the electric motor 10a, wherein under the premise that the driving force exerted by the motor 120a is transmitted to the driving wheels W without involving a large loss of the torque, the durability of the universal joint J is enhanced by suppressing largely the generation of fretting wear between constituent members of the universal joint J. <P>SOLUTION: In the normal condition in which no vibration is generated in the driving mechanism and the driving wheels W, a prescribed joint angle θ is set between the output shaft 10c of the driving mechanism and the rotary shaft 32 of the driving wheel W so as to admit free motions at the fitting parts of ball 53, roller 63, and a spider 73, and thereby generation of fretting wear is suppressed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a drive device for vehicle drive wheels.

As one type of vehicle drive device, there is a drive device for individually driving each wheel constituting the vehicle. In the present invention, the drive device is referred to as a drive device for vehicle drive wheels. Thus, the drive device for a vehicle drive wheel is a drive device for driving a drive wheel rotatably supported by a suspension device assembled to a vehicle body via a support mechanism, and is an in-wheel motor drive system. It is known as a drive device. The drive device of this type is a drive mechanism that uses an electric motor as a drive source, and the drive mechanism is supported by the support mechanism, and a constant velocity universal joint is connected to the rotation shaft of the drive wheel. Are connected through. In the drive device of this type, the drive wheels that are supported by the vehicle so as to be swingable in the vertical direction are rotationally driven by driving an electric motor that constitutes the drive mechanism, thereby causing the vehicle to travel forward or backward. (See Patent Document 1).
JP 2005-238935 A

  By the way, in the drive device of this type, the output shaft of the drive mechanism and the rotation shaft of the drive wheel that are connected to each other via a constant velocity universal joint are connected coaxially. For this reason, in the drive device adopting such a connection structure, the driving force of the electric motor constituting the drive mechanism is transmitted to the rotating shaft of the drive wheel with very little torque loss, and the drive wheel is efficiently driven. can do. However, in the connection structure, since the output shaft of the drive mechanism and the rotation shaft of the drive wheel are connected coaxially, vibration transmitted from the vehicle body side is coupled to the constant velocity universal joint that adopts the connection structure. This acts in a vertical state on the part.

  For this reason, in the case of a ball-type or tripod-type constant velocity universal joint, the vibration acts in a vertical state with respect to the bottom of the groove portion into which the ball or roller is fitted. It is sandwiched by the bottom of the groove and is subject to vibration in a state where free movement within the groove is restricted, so that fine wear between components constituting the constant velocity universal joint, in other words, fretting wear Will greatly affect the durability of the constant velocity universal joint. Further, in the constant velocity universal joint that is a hook-type universal joint, the vibration acts in a vertical state with respect to the fitting portion of each yoke to which each leg portion of the spider is fitted, and as a result, Each leg part of the spider is pressed into each fitting part and is subjected to vibration in a state where free movement in the fitting part is restricted, and between the constituent members constituting the constant velocity universal joint. Fine movement wear, in other words, fretting wear occurs, which greatly affects the durability of the constant velocity universal joint.

  Accordingly, an object of the present invention is to provide a driving force from an electric motor that constitutes a driving mechanism between components constituting a constant velocity universal joint on the premise that the driving force is transmitted to a driving wheel without causing a large torque loss. It is to improve the durability of the constant velocity universal joint by significantly suppressing the occurrence of fretting wear.

  The present invention relates to a drive device for vehicle drive wheels. A drive device for a vehicle drive wheel to which the present invention is applied is a drive device of a type that drives a drive wheel that is rotatably supported by a suspension device assembled to a vehicle body via a support mechanism. Thus, the drive device according to the present invention is a drive mechanism using an electric motor as a drive source, and the output shaft of the drive mechanism is freely adjustable at the same speed as the rotation shaft of the drive wheel while being supported by the support mechanism. In a normal state where the drive mechanism and the drive wheel are not coupled with each other via a joint, a predetermined joint angle is set between the output shaft of the drive mechanism and the rotation shaft of the drive wheel. The joint angle is set to a predetermined angle in the range of more than 0 degrees to 15 degrees in accordance with the type of constant velocity universal joint to be employed.

  In the vehicle drive wheel drive device according to the present invention, the drive mechanism includes a reduction mechanism that reduces the drive speed of the electric motor, and the output shaft of the reduction mechanism is used as the output shaft of the drive mechanism. A predetermined joint angle can be set between the output shaft and the rotating shaft by connecting the output shaft to the rotating shaft of the drive wheel via the constant velocity universal joint.

  In the vehicle driving wheel driving device according to the present invention, when a ball type constant velocity joint or a swing tripod type constant velocity joint is adopted as the constant velocity universal joint, the joint angle is set to 4 degrees. When the slide tripod type constant velocity joint is used as the constant velocity universal joint and is set to a predetermined angle in the range of 15 degrees or less, the joint angle is a predetermined angle in the range of 2 degrees or more and 5 degrees or less. When a hook-type universal joint is adopted as the constant velocity universal joint, it is preferable to set the joint angle to a predetermined angle in the range of more than 0 degrees to 3 degrees.

  In the drive device for a vehicle drive wheel according to the present invention, a predetermined joint angle is set between the output shaft and the rotation shaft in the connection structure that connects the output shaft of the drive mechanism and the rotation shaft of the drive wheel. For this reason, the vibration transmitted from the vehicle body side acts on the ball or roller fitted in the groove portion of the constant velocity universal joint adopting the connection structure in an oblique direction with respect to the bottom portion of the groove portion. Etc. will be subjected to vibration in a state where free movement in the groove is allowed, and each leg part of the spider acts in an oblique direction with respect to the inside of each fitting part, and the spider is fitted. Vibrations are received in a state where free movement within the joint portion is allowed. For this reason, generation | occurrence | production of the fine movement wear between the structural members which comprise a constant velocity universal joint, in other words, generation | occurrence | production of fretting wear can be suppressed significantly, and the durability of a constant velocity universal joint is improved greatly. be able to.

  In the vehicle drive wheel drive device according to the present invention, specifically, the drive mechanism can be configured to include an electric motor and a speed reduction mechanism that reduces the drive speed of the electric motor. The output shaft of the speed reduction mechanism is connected to the rotating shaft of the drive wheel via a constant velocity universal joint, and a predetermined joint angle is set between the rotating shaft and the rotating shaft.

  Further, in the vehicle driving wheel driving device according to the present invention, the joint angle between the output shaft and the rotating shaft is set according to the relationship between the reduction in transmission torque loss and the reduction in fretting wear. It is preferable that the different constant velocity universal joints are set corresponding to each type of constant velocity universal joints.

  In the vehicle driving wheel drive device according to the present invention, when a ball-type constant velocity joint or a swing-type torpedo-type constant velocity joint is adopted as the constant velocity universal joint, the joint angle is not less than 4 degrees and not more than 15 degrees. It is preferable to set a predetermined angle in the range. In a constant velocity universal joint of this type, if the joint angle is less than 4 degrees, the load of the ball, etc., fluctuates within a narrow range and fretting wear tends to occur. If the joint angle exceeds 15 degrees, the load of the ball, etc. Fluctuations increase and the life of the constant velocity universal joint decreases.

  Further, in the vehicle driving wheel drive device according to the present invention, when a sliding tripod type constant velocity joint is adopted as the constant velocity universal joint, a predetermined angle in the range of 2 degrees or more and 5 degrees or less is adopted. It is preferable to set to. In this type of constant velocity universal joint, if the joint angle is less than 2 degrees, the fretting wear is likely to occur due to load fluctuation in a narrow range of rollers, and if the joint angle exceeds 5 degrees, the induced thrust force is large. Become.

  In the vehicle driving wheel drive device according to the present invention, when a hook-type universal joint is adopted as the constant velocity universal joint, the joint angle is set to a predetermined angle in the range of more than 0 degree to 3 degrees. It is preferable to set. In the constant velocity universal joint of this type, if the joint angle is set larger than this, torque fluctuations will occur.

  The present invention is a drive device for driving a drive wheel that is rotatably supported by a suspension device assembled to a vehicle body via a support mechanism, and includes a drive mechanism using an electric motor as a drive source. Device. In FIG. 1, the drive device of the drive wheel for vehicles which concerns on one Embodiment of this invention is shown. The drive device D is an in-wheel motor drive type drive device, and includes an electric motor 10a, a speed reduction mechanism 10b, and an output shaft 10c, and knuckle the upper arm 21 and the lower arm 22 constituting the suspension device S of the vehicle. The drive wheel W supported via 23 functions to rotate.

  The drive wheel W includes a wheel hub 32 attached to the center of the wheel disc 31, and the wheel hub 32 is rotatably supported by the knuckle 23 via a hub bearing 33. Arper knuckle portion 23a constituting knuckle 23 that supports drive wheel W is connected to the tip portion of upper arm 21 via ball joint 23a1 at the tip portion, and lower knuckle portion 23b is connected to the tip end thereof. Is connected to the tip of the lower arm 22 via a ball joint 23b1.

  The base end portions of the arper arm 21 and the lower arm 22 constituting the suspension device S are connected to the side portion of the vehicle body so as to be movable up and down, and the upper end portion is connected to the vehicle body side in the middle of the lower arm 22. The lower end portion of the shock absorber 24 connected to is rotatably connected. Thus, the drive wheel W is supported so as to be movable up and down with respect to the suspension device S, and is assembled so as to be rotatable with respect to the knuckle 23.

  Thus, in the driving device D, the electric motor 10a, the speed reduction mechanism 10b, and the output shaft 10c constituting the driving mechanism are housed in the case 10d. The driving device D is shown in FIG. It is shown schematically. The case 10d that houses the electric motor 10a, the speed reduction mechanism 10b, and the output shaft 10c constituting the driving device D is supported by the upper knuckle portion 23a of the knuckle 23 via a damper 23a2 at the upper part of the outer periphery thereof. Further, at the lower part of the outer periphery, the knuckle 23 is supported on the lower knuckle portion 23b via a damper 23b2.

  The electric motor 10 a constituting the driving device D is a conventionally known one, and includes a stator 11 and a rotor 12. The stator 11 is formed by winding a stator coil around a stator core, and is fixed to the inner periphery of the case 10d. The rotor 12 is fixed to the outer periphery of the motor output shaft 13 and is concentrically disposed on the inner peripheral side of the stator 11. The motor output shaft 13 is rotatably supported in the case 10d.

  The speed reduction mechanism 10b is a speed reduction mechanism having a planetary gear unit as a basic configuration, and is a conventionally known mechanism including a sun gear shaft, a sun gear, a pinion gear, a planetary carrier, and a ring gear. In the speed reduction mechanism 10b, the sun gear shaft is connected to the motor output shaft 13 of the electric motor 10a, and is rotatably supported in the case 10d via a bearing. The output shaft 10c is connected to the output member of the speed reduction mechanism 10b so as to be able to transmit torque, is positioned coaxially with the motor output shaft 13 of the electric motor 10a, and penetrates the central portion of the case 10d to the case 10d. It is rotatably supported.

  The wheel hub 32 assembled to the wheel disc 31 of the drive wheel W constitutes the rotation shaft of the drive wheel W, and the output shaft 10c constituting the drive device D is connected to the wheel hub 32 and the wheel hub 32 They are connected via a constant velocity universal joint J disposed in the inner hole. Since the wheel hub 32 constitutes the rotation axis of the drive wheel W, the wheel hub 32 may be hereinafter referred to as the rotation axis 32 of the drive wheel W.

  In the connection structure of the output shaft 10c and the rotating shaft 32 (wheel hub) constituting the driving mechanism of the driving device D, a predetermined joint angle θ is set between the output shaft 10c and the rotating shaft 32. The joint angle θ is an intersection angle formed by the axis L1 of the output shaft 10d and the axis L2 of the rotary shaft 32. In the driving device D, the joint angle θ is set to a predetermined angle in accordance with the type of the constant velocity universal joint J to be used within a range of more than 0 degrees and within 15 degrees. Note that reference numeral 41 shown in FIG. 1 is a tire assembled on the rim of the wheel desk 31, and reference numeral 42 is a caliper brake.

  In the driving device D configured as described above, the electric motor 10a is driven by supplying current to the electric motor 10a from the switching circuit mounted on the vehicle body, and the driving force of the electric motor 10a is reduced by the speed reduction mechanism 10b. The output is output to the output shaft 10c in a decelerated state, and transmitted to the rotating shaft 32 (wheel hub) of the drive wheel W connected to the output shaft 10c via the constant velocity universal joint J. As a result, the drive wheels W are driven to run the vehicle.

  By the way, in the drive device D, a predetermined joint angle θ is set between the output shaft 10 c and the rotation shaft 32 in the connection structure that connects the output shaft 10 c and the rotation shaft 32 of the drive wheel W. For this reason, the vibration transmitted from the vehicle body side significantly suppresses the occurrence of fine wear between constituent members constituting the constant velocity universal joint J adopting the connection structure, in other words, the occurrence of fretting wear. The durability of the constant velocity universal joint J can be greatly improved.

  In the case where the constant velocity universal joint J is a ball type constant velocity joint, a swing type triport type constant velocity joint, or a sliding type tripod type constant velocity joint, vibration transmitted from the vehicle body side adopts the connection structure, etc. The ball or roller fitted in the groove portion of the quick universal joint J acts in an oblique direction with respect to the bottom portion of the groove portion, and the ball or roller vibrates in a state where free movement in the groove portion is allowed. The occurrence of fine wear between the components constituting the constant velocity universal joint J, in other words, the occurrence of fretting wear can be greatly suppressed, and the durability of the constant velocity universal joint J can be improved. It can be greatly improved.

  When the constant velocity universal joint J is a hook-type universal joint, the vibration transmitted from the vehicle body acts on each leg portion of the spider in an oblique direction with respect to the inside of each fitting portion. Is subjected to vibration in a state in which free movement within the fitting portion is allowed, and fine wear between components constituting the constant velocity universal joint J occurs, in other words, fretting wear. Generation | occurrence | production can be suppressed significantly and the durability of a constant velocity universal joint can be improved greatly.

  In the driving device D, the constant velocity universal joint J used to connect the output shaft 10c and the rotary shaft 32 includes a ball type constant velocity joint, a slide type tripod type constant velocity joint, and a swing type tripod type constant velocity. Various types of constant velocity universal joints such as joints and hook joints can be used. In this case, the joint angle θ between the output shaft 10c and the rotating shaft 32 is preferably set appropriately according to the type of constant velocity universal joint to be employed. 2 to 7 illustrate constant velocity universal joints that can be employed in the driving device D according to the present invention. The constant velocity universal joints 50a, 50b and 50c shown in FIGS. 2 to 4 are three types of ball type constant velocity joints, and the constant velocity universal joints 60a and 60b shown in FIGS. 5 and 6 are two types of tripod type. The constant velocity universal joint 70 shown in FIG. 7 is a hook-type universal joint.

  An undercut-free constant velocity joint 50a (UFJ) shown in FIG. 2 includes an outer race 51a, an inner race 52a, a ball 53a, and a ball cage 54a that holds the ball 53a. 51a is fixed to the tip of the rotating shaft 32 which is a wheel hub, and the inner race 52a is connected to the tip of the output shaft 10c of the driving device D so as to be able to transmit torque, thereby connecting the output shaft 10c and the rotating shaft 32.

  A Rzeppa constant velocity joint 50b (BJ), which is a constant velocity universal joint shown in FIG. 3, includes an outer race 51b, an inner race 52b, a ball 53b, and a ball cage 54b that holds the ball 53b. The inner race 52b is fixed to the tip of the output shaft 10c of the driving device D so as to be able to transmit torque, and connects the output shaft 10c and the rotary shaft 32.

  A double offset constant velocity joint 50c (DOJ) which is a constant velocity universal joint shown in FIG. 4 includes an outer race 51c, an inner race 52c, a ball 53c, and a ball cage 54c for holding the ball 53c. Is fixed to the tip of the rotating shaft 32 as a wheel hub, and the inner race 52c is connected to the tip of the output shaft 10c of the driving device D so as to be able to transmit torque, thereby connecting the output shaft 10c and the rotating shaft 32.

  When the undercut-free constant velocity joint 50a, the Rzeppa constant velocity joint 50b, or the double offset constant velocity joint 50c having such a configuration is employed, the joint angle θ shown in FIG. 1 is not less than 4 degrees and not more than 15 degrees. It is preferable to set a predetermined angle in the range. In these constant velocity universal joints, when the joint angle θ is less than 4 °, the load of the ball or the like fluctuates easily and fretting wear easily occurs. When the joint angle θ exceeds 15 °, the ball or the like The load fluctuation increases and the life of the constant velocity universal joint is reduced.

  A sliding tripod type constant velocity joint 60a (GI), which is a constant velocity universal joint shown in FIG. 5, includes an outer race 61a, a tripod 62a, and a roller 63a. The tripod 62a is connected to the tip of the output shaft 10c of the driving device D so that torque can be transmitted, and connects the output shaft 10c and the rotary shaft 32.

  A swing-type tripod type constant velocity 60b (GE), which is a constant velocity universal joint shown in FIG. 6, includes an outer race 61b, a tripod 62b, and a roller 63b. The tripod 62b is connected to the tip of the output shaft 10c of the drive device D so that torque can be transmitted, and connects the output shaft 10c and the rotary shaft 32.

  When the slide type tripod type constant velocity joint 60a or the swing type tripod type constant velocity joint 60b having such a configuration is employed, the joint angle θ shown in FIG. 1 is a predetermined angle in the range of 2 degrees to 5 degrees. It is preferable to set to. In these constant velocity universal joints, if the joint angle θ is less than 2 degrees, the roller fluctuates the load in a narrow range and fretting wear occurs. If the joint angle θ exceeds 5 degrees, the induced thrust force increases. Become.

  A hook-type universal joint 70 that is a constant velocity universal joint shown in FIG. 7 includes a shaft yoke 71, a joint yoke 72, and a spider 73. The shaft yoke 71 is fixed to the tip of the output shaft 10c. Is assembled at the tip of the rotating shaft 32 which is a wheel hub, and the spider 73 is rotatably fitted in fitting holes provided in each arm portion of the shaft yoke 71 with its leg portions extending in the vertical direction. The leg portions extending in the lateral direction are fitted into fitting holes provided in the arm portions of the joint yoke 72 so as to be freely rotatable, and the output shaft 10c and the rotary shaft 32 are connected. When the hook joint 70 having such a configuration is employed, the joint angle θ shown in FIG. 1 is set to a predetermined angle in the range of more than 0 degrees to 3 degrees. In the hook type joint 70, when the joint angle θ is set larger than this, torque fluctuation occurs.

4 is a longitudinal side view schematically showing a state in which the drive device according to the present invention is supported by a vehicle suspension device. It is a vertical side view which shows the undercut free type constant velocity joint which can be employ | adopted as a constant velocity universal joint which is a connection means of the drive device which concerns on this invention. It is a vertical side view which shows the Rzeppa type constant velocity joint which can be employ | adopted as a constant velocity universal joint which is a connection means of the drive device which concerns on this invention. It is a vertical side view which shows the double offset type constant velocity joint which can be employ | adopted as a constant velocity universal joint which is a connection means of the drive device which concerns on this invention. It is a vertical side view which shows the slide type tripod type | mold constant velocity joint which can be employ | adopted as a constant velocity universal joint which is a connection means of the drive device which concerns on this invention. It is a vertical side view which shows the swing type tripod type | mold constant velocity joint which can be employ | adopted as a constant velocity universal joint which is a connection means of the drive device which concerns on this invention. It is a disassembled perspective view which shows the hook type universal joint which can be employ | adopted as a constant velocity universal joint which is a connection means of the drive device which concerns on this invention.

Explanation of symbols

D: Driving device, W: Driving wheel, S: Suspension device, J: Constant velocity universal joint, 10a ... Electric motor, 10b ... Deceleration mechanism, 10c ... Output shaft, 10d ... Case, 11 ... Stator, 12 ... Rotor, 13 Motor output shaft, 21 Upper arm, 22 Lower arm, 23 Knuckle, 23a Arper knuckle, 23b Lower knuckle, 23a1, 23b1, Ball joint, 23a2, 23b2 Damper, 24 Shock absorber, 31 Wheel Disc, 32 ... Wheel hub, 33 ... Hub bearing, 41 ... Tire, 42 ... Break, 50a ... Undercut-free type constant velocity joint, 50b ... Zepper type constant velocity joint, 50c ... Double offset type constant velocity joint, 51a, 51b , 51c ... outer race, 52a, 52b, 52c ... inner 53a, 53b, 53c ... ball, 54a, 54b, 54c ... ball cage, 60a ... slide type tripod type constant velocity joint, 60b ... swing type tripod type constant velocity joint, 61a, 61b ... outer race, 62a, 62b ... tripod, 63a, 63b ... roller, 70 ... hook type universal joint, 71 ... shaft yoke, 72 ... joint yoke, 73 ... spider.

Claims (5)

A drive device for driving a drive wheel rotatably supported by a suspension device assembled to a vehicle body via a support mechanism, the drive device being a drive mechanism using an electric motor as a drive source, the support device In a normal state where the output shaft of the drive mechanism is connected to the rotary shaft of the drive wheel via a constant velocity universal joint while being supported by the mechanism, and vibration is not generated in the drive mechanism and the drive wheel. A predetermined joint angle is set between the output shaft of the drive mechanism and the rotation shaft of the drive wheel, and the joint angle exceeds 15 degrees depending on the type of constant velocity universal joint to be used. A drive device for a drive wheel for a vehicle, wherein the drive device is set to a predetermined angle in a range up to. The drive device for a vehicle drive wheel according to claim 1, wherein the drive mechanism includes a reduction mechanism that reduces the drive speed of the electric motor, and an output shaft of the reduction mechanism constitutes an output shaft of the drive mechanism. The drive wheel drive device for vehicles is characterized in that the drive wheel is connected to the rotary shaft via the constant velocity universal joint, and a predetermined joint angle is set between the rotary shaft and the rotary shaft. . 3. The drive device for a vehicle driving wheel according to claim 1, wherein when the ball type constant velocity joint or the swing type tripod type constant velocity joint is adopted as the constant velocity universal joint, the joint angle is set to 4 degrees. A driving device for a vehicle driving wheel, wherein the driving angle is set to a predetermined angle in a range of 15 degrees or less. The drive device for a vehicle driving wheel according to claim 1 or 2, wherein when the slide tripod type constant velocity joint is adopted as the constant velocity universal joint, the joint angle is in the range of 2 degrees to 5 degrees. A drive device for a vehicle drive wheel, wherein the drive angle is set to a predetermined angle. 3. The drive device for a vehicle drive wheel according to claim 1, wherein when a hook-type universal joint is used as the constant velocity universal joint, the joint angle exceeds a predetermined angle ranging from 0 degree to 3 degrees. A drive device for a vehicle drive wheel, characterized by being set to an angle of

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