Vehicle differential device

Abstract

The present invention provides a vehicle differential device that can sufficiently dampen the pulsation of thrust force transmitted from the pinion gear to the side gear, thereby suppressing vibrations transmitted to the vehicle body and occupants caused by the pulsation of thrust force. [Solution] A vehicle differential device 10 comprising a differential case 16, pinion gears 20, 22 rotatably supported around the pinion shaft 18 by a pinion shaft 18, a pair of side gears 24, 26 provided inside the differential case 16 and meshing with the pinion gears 20, 22, and an axle housing 32 that rotatably supports the differential case 16 via bearings 28, 30, wherein elastic bodies 34a, 34b for damping thrust force pulsation are provided between the side gears 24, 26 and the differential case 16, and between the differential case 16 and the axle housing 32.

Description

Technical Field

[0001] The present invention relates to a differential device for a vehicle, and suppresses pulsation generated in the thrust direction of a drive shaft.

Background Art

[0002] A vehicle differential device including a differential case (hereinafter referred to as a differential case), a pinion gear rotatably supported around the pinion shaft by the pinion shaft, a pair of side gears provided in the differential case and meshed with the pinion gear, and an axle housing rotatably supporting the differential case via bearings is well known. For example, the vehicle differential device described in Patent Document 1 is such a device. In Patent Document 1, an elastic body made of a spring material such as a conical spring washer is disposed between the side gear and the differential case to press the side gear toward the pinion gear.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the above-described differential device is used, the force transmitted from the pinion gear to the side gear varies with the tooth meshing, and the thrust direction component of the transmitted force also varies, so pulsation occurs in the thrust force. When the device disclosed in Patent Document 1 is used, the pulsation of the thrust force cannot be sufficiently attenuated, so there is a problem that vehicle vibration occurs due to the pulsation of the thrust force.

[0005] The present invention has been made to solve the above-mentioned problems, and its objective is to provide a vehicle differential device that can suppress vibrations transmitted to the vehicle body and occupants. [Means for solving the problem]

[0006] The gist of the present invention is a vehicle differential device comprising a differential case, a pinion gear rotatably supported around the pinion shaft by a pinion shaft, a pair of side gears provided inside the differential case and meshed with the pinion gear, and an axle housing that rotatably supports the differential case via bearings, wherein an elastic body for damping thrust force pulsation is provided between the side gears and the differential case, and between the differential case and the axle housing. [Effects of the Invention]

[0007] According to the vehicle differential device of the present invention, in the thrust force pulsation transmission path from the side gear, which is the source of thrust force pulsation, through the differential case and the bearing to the axle housing, the elastic body is provided not only between the side gear and the differential case, but also between the bearing and the axle housing, thereby suppressing the thrust force pulsation transmitted from the axle housing to the vehicle body. This makes it possible to suppress vibrations transmitted to the vehicle body and the occupants. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view illustrating the configuration of a vehicle differential device to which the present invention is suitably applied. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in the following embodiments, the drawings have been simplified or modified as appropriate, and the dimensional ratios and shapes of each part are not necessarily depicted accurately. [Examples]

[0010] Figure 1 is a cross-sectional view illustrating the configuration of a vehicle differential device 10 to which the present invention is suitably applied. Hereinafter, the vehicle differential device 10 will be referred to as the differential device 10. The differential device 10 is provided in the power transmission path between a vehicle power source, such as an engine (not shown), and drive shafts 12 and 14 that rotate a pair of left and right drive wheels (not shown).

[0011] As shown in Figure 1, the differential device 10 includes a differential case 16, a pinion shaft 18, pinion gears 20 and 22 rotatably supported around the pinion shaft 18, a pair of side gears 24 and 26 that mesh with the pinion gears 20 and 22, are arranged facing each other across the pinion shaft 18, and are rotatably supported by the differential case 16 around the axis of rotation CL, an axle housing 32 that rotatably supports the differential case 16 around the axis of rotation CL via bearings 28 and 30, and elastic bodies 34a and 34b, which will be described later.

[0012] The pinion shaft 18 is fixed to the differential case 16 by a knock pin 36. The differential case 16 is composed of two parts, which are integrally fastened together by fastening bolts 38. The axle housing 32 is composed of multiple parts, which are integrally fastened together by fastening bolts 40. The pinion gears 20 and 22 are pressed against pinion washers 42 and 44, which are disposed between them and the inner wall surface of the differential case 16, by the reaction force generated by their meshing with the side gears 24 and 26. The pinion washers 42 and 44 are partially spherical in shape, with the pinion shaft 18 inserted through their central holes, and are, for example, circular plates made of bearing metal. When used with a lubricant (not shown), they play a role in reducing sliding resistance while bearing the load between the inner wall surface of the differential case 16 and the pinion gears 20 and 22.

[0013] A ring gear 48 is fixed to an outer peripheral projection 16a projecting outward from the outer peripheral surface of the differential case 16 by fastening bolts 46. The drive torque from the vehicle power source is transmitted to the differential case 16 via a drive gear (not shown) that meshes with the ring gear 48. The drive torque is transmitted to the side gears 24 and 26 via a pinion shaft 18 and pinion gears 20 and 22, and then to a pair of left and right drive wheels (not shown) via drive shafts 12 and 14, each of which is spline-fitted to the side gears 24 and 26 so as not to rotate relative to the other.

[0014] The driving force transmitted from the pinion gears 20 and 22 to the side gears 24 and 26 is transmitted perpendicular to the tooth surfaces of the side gears 24 and 26. Therefore, the transmitted force includes torque, which is the circumferential component around the rotation axis CL of the side gears 24 and 26, and thrust force, which is the component in the direction of the rotation axis CL of the side gears 24 and 26. The thrust force acts on each of the side gears 24 and 26 in opposite directions to the left and right drive wheels (not shown).

[0015] The thrust force acting on the side gears 24 and 26 is transmitted to the differential case 16 via an elastic body 34a disposed between the side gears 24 and 26 and the differential case 16. The thrust force is then transmitted from the differential case 16 to the adjacent bearings 28 and 30, and then to the axle housing 32 via an elastic body 34b disposed between the bearings 28 and 30 and the axle housing 32.

[0016] The force transmitted from the pinion gears 20 and 22 to the side gears 24 and 26 fluctuates along with the change in meshing state due to the rotation of the pinion gears 20 and 22, and the thrust force among the transmitted forces also fluctuates. For example, during cornering, pulsations occur in the thrust force, but these are absorbed by the elastic bodies 34a and 34b arranged in series along the transmission path described above, and the pulsations of the thrust force transmitted to the axle housing 32 can be sufficiently attenuated.

[0017] The elastic bodies 34a and 34b are composed of, for example, disc springs (conical springs in which annular leaf spring members are formed in the shape of the side of a cone), annular wave springs, or annular bodies made of synthetic rubber, and preferably have an elastic modulus that elastically deforms in response to a thrust force of 10 to 100 N and absorbs the vibration of the thrust force, thereby damping the pulsation of the thrust force.

[0018] As described above, according to the differential device 10 of this embodiment, thrust force pulsations are absorbed by elastic bodies 34a and 34b arranged in series on the thrust force pulsation transmission path, respectively, and the thrust force pulsations transmitted to the axle housing 32 can be sufficiently attenuated. As a result, vibrations transmitted from the axle housing 32 to the passenger compartment via the suspension system are suppressed, and the occurrence of vehicle vibrations transmitted to the vehicle body and occupants due to thrust force pulsations can be suitably suppressed.

[0019] Although embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is also applicable to other embodiments.

[0020] For example, in the above-described embodiment, the elastic bodies 34b are disposed between the bearings 28 and 30 and the axle housing 32, but may be disposed between the differential case 16 and the bearings 28 and 30. Even in this case, since the elastic bodies 34a and 34b are arranged in series on the transmission path of the pulsation of the thrust force, the pulsation of the thrust force can be sufficiently attenuated.

[0021] Note that the above is merely one embodiment, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art.

Explanation of Signs

[0022] 10: Vehicle differential device 12, 14: Drive shaft 16: Differential case 18: Pinion shaft 20, 22: Pinion gear 24, 26: Side gear 28, 30: Bearing 32: Axle housing 34a, 34b: Elastic body CL: Axis of rotation

Claims

[Claim 1] A vehicle differential device comprising: a differential case; a pinion gear rotatably supported around a pinion shaft fixed to the differential case by a pinion shaft; a pair of side gears provided inside the differential case and meshed with the pinion gear; and an axle housing that rotatably supports the differential case via bearings, Elastic bodies that dampen the pulsation of thrust force acting in the direction of the rotation axis on the side gear are provided between the side gear and the differential case, and between the differential case and the axle housing. A vehicle differential device characterized by the following features.

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