Vehicle power transmission system

Abstract

The present invention provides a vehicle power transmission device that can reduce vehicle floor vibration caused by the thrust force of the drive shaft. [Solution] An elastic member is further provided in the power transmission path between the differential gear and the drive wheel. This elastic member is sandwiched between the differential gear or a first member integrally connected to the differential gear and the drive shaft or a second member integrally connected to the drive shaft. This suppresses vibration transmission caused by the thrust force of the drive shaft. Therefore, it is possible to reduce vehicle floor vibration caused by the thrust force of the drive shaft.

Description

Technical Field

[0001] The present invention relates to a vehicle power transmission device including a drive shaft that transmits power from a differential gear to drive wheels.

Background Art

[0002] A vehicle power transmission device including a differential gear that distributes power from a power source to left and right drive wheels, and left and right drive shafts provided in a power transmission path between the differential gear and the drive wheels is well known. For example, the vehicle described in Patent Document 1 is such a device. Patent Document 1 discloses a structure in which a drive shaft is spline-fitted and connected to a side gear included in a differential 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, in the vehicle described in Patent Document 1, since the differential gear and the drive shaft are rigidly connected by spline fitting, it is difficult to absorb vibrations transmitted in the power transmission path. Therefore, it is difficult to suppress vibration transmission caused by a force in the thrust direction of the drive shaft, that is, in the direction of the rotation axis.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a vehicle power transmission device capable of reducing vehicle floor vibrations caused by a force in the thrust direction of a drive shaft.

Means for Solving the Problems

[0006] The gist of the first invention is a vehicle power transmission device comprising (a) a differential gear for distributing power from a power source to left and right drive wheels, and left and right drive shafts provided in a power transmission path between the differential gear and the drive wheels, and further comprising (b) an elastic member sandwiched between a first member provided in the power transmission path and integrally connected to the differential gear or the differential gear, and a second member integrally connected to the drive shaft or the drive shaft. [Effects of the Invention]

[0007] According to the first invention described above, an elastic member is further provided in the power transmission path between the differential gear and the drive wheel. This elastic member is a member sandwiched between the differential gear or a first member integrally connected to the differential gear and the drive shaft or a second member integrally connected to the drive shaft. This suppresses the transmission of vibrations caused by the thrust force of the drive shaft. Therefore, it is possible to reduce vehicle floor vibrations caused by the thrust force of the drive shaft. [Brief explanation of the drawing]

[0008] [Figure 1] This figure illustrates the schematic configuration of a vehicle equipped with a vehicle power transmission device to which the present invention is applied. [Figure 2] This diagram illustrates an example of a coupling structure between a differential gear and a drive shaft. [Figure 3] This figure illustrates an example of a coupling structure between a differential gear and a drive shaft, different from the coupling structure shown in Figure 2. (a) shows an example of a coupling structure that separates the fastening function and the damping function. (b) shows an example of a coupling structure that can maintain axial force using a spring. (c) shows an example of a coupling structure that can prevent pinching and loosening and protect the internal structure using a plate. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Examples]

[0010] Figure 1 is a diagram illustrating the schematic configuration of a vehicle 10 equipped with a vehicle power transmission device 16 (hereinafter referred to as "power transmission device 16") to which the present invention is applied. In Figure 1, the vehicle 10 comprises a power source 12, left and right drive wheels 14, and a power transmission device 16 provided in the power transmission path between the power source 12 and the drive wheels 14. The power source 12 is, for example, an engine as a known internal combustion engine. The power source 12 may also be, for example, an electric motor as a known rotating electric machine in addition to or instead of an engine. The drive wheels 14 include a left drive wheel 14L and a right drive wheel 14R. The above "left and right" refers to left and right with respect to the forward direction of the vehicle 10.

[0011] The power transmission device 16 includes a counter gear mechanism 20, a counter shaft 22, a final gear 24, a differential gear 26, etc., within a housing 18. The housing 18 is a non-rotatable, non-rotating member attached to the vehicle body. The power transmission device 16 also includes left and right drive shafts 28, etc., provided in the power transmission path between the differential gear 26 and the drive wheels 14. The counter gear mechanism 20 is a gear pair having a drive gear 20a and a driven gear 20b that meshes with the drive gear 20a. The drive gear 20a is connected to the power source 12, for example, directly or via a transmission (not shown). The driven gear 20b is connected to the final gear 24 via the counter shaft 22. The final gear 24 meshes with the differential ring gear 30 of the differential gear 26. The drive shaft 28 includes a left drive shaft 28L and a right drive shaft 28R. The drive shaft 28 transmits power from the differential gear 26 to the drive wheels 14. The power transmission device 16 transmits power from the power source 12 to the drive wheels 14.

[0012] The differential gear 26 comprises a differential ring gear 30, a differential case 32, left and right differential side gears 34, a differential pinion 36, a pinion shaft 38, and a differential shaft portion 40. The differential ring gear 30 is integrally connected to the outside of the differential case 32. The differential ring gear 30 and the differential case 32 are input rotating members to which power from the power source 12 is input. The differential case 32 is supported by the housing 18 so as to be rotatable relative to it via bearings (not shown). The differential case 32 is a case that houses the differential side gears 34, the differential pinion 36, and the pinion shaft 38, etc.

[0013] The differential side gear 34 includes a left side gear 34L and a right side gear 34R. The differential side gear 34 has spline teeth formed on the inner circumferential surface of a through hole into which the differential shaft portion 40 is fitted so as not to rotate relative to it. The differential shaft portion 40 includes a left differential shaft portion 40L and a right differential shaft portion 40R. The differential shaft portion 40 has spline teeth formed on the outer circumferential surface of the end on the differential side gear 34 side and fits so as not to rotate relative to the inner circumferential surface of the differential side gear 34. The end of the differential shaft portion 40 on the drive shaft 28 side is fitted so as to rotate relative to it into a through hole 32a formed in the differential case 32.

[0014] The differential pinion 36 meshes with the differential side gear 34. The differential pinion 36 is supported by the pinion shaft 38 so as to be rotatable relative to it. The pinion shaft 38 is fitted into a through hole (not shown) formed in the differential case 32 and is fixed to the differential case 32 so as not to be rotatable relative to it.

[0015] The differential side gears 34 are a pair of output rotating members to which the power input to the differential case 32 is distributed. The differential gear 26 is a differential device that distributes power from the power source 12 to the left and right drive wheels 14 and allows differential rotation between the left and right drive wheels 14.

[0016] Incidentally, if the differential gear 26 and the drive shaft 28 are rigidly coupled, vibrations transmitted in the power transmission path are less likely to be absorbed. As a result, vibration transmission caused by the thrust force of the drive shaft 28 is less likely to be suppressed. Therefore, the power transmission device 16 has a coupling structure in which an elastic member 70 (see Figure 2 described later) is sandwiched between the differential gear 26 and the drive shaft 28.

[0017] Figure 2 illustrates an example of the coupling structure between the differential gear 26 and the drive shaft 28. While Figure 2 shows the right drive shaft 28R, the structure of the left drive shaft 28L and the coupling structure between the differential gear 26 and the left drive shaft 28L are basically the same. Therefore, in Figure 2, the reference numerals are used without distinguishing between left and right.

[0018] In Figure 2, the drive shaft 28 comprises an intermediate shaft 50, a first joint 52, and a second joint 54. The intermediate shaft 50 is a power transmission shaft that transmits power from the differential gear 26 to the drive wheels 14. The first joint 52 is a constant velocity universal joint and is an inboard joint connected to the input side, i.e., the differential gear 26 side end of the intermediate shaft 50, by spline fitting. The second joint 54 is a constant velocity universal joint and is an outboard joint connected to the output side, i.e., the drive wheel 14 side end of the intermediate shaft 50, by spline fitting.

[0019] The outer ring 54a of the second joint 54 is provided with a wheel axle portion 56 that is positioned to protrude toward the drive wheel 14 and in the direction of the rotation axis. A hub bearing 58, which is provided on the vehicle 10 and connected to the drive wheel 14, is fitted to the wheel axle portion 56 by spline fitting. The wheel axle portion 56 is connected to the drive wheel 14 via the hub bearing 58.

[0020] The drive shaft 28 further includes bellows-shaped boots 60 and 62 made of a soft resin material. The opening between the intermediate shaft 50 and the outer ring 52a of the first joint 52 is covered by the boot 60. The large-diameter end of the boot 60 is fitted around the outer ring 52a, and the small-diameter end is fitted to the intermediate shaft 50. The opening between the intermediate shaft 50 and the outer ring 54a of the second joint 54 is covered by the boot 62. The large-diameter end of the boot 62 is fitted around the outer ring 54a, and the small-diameter end is fitted to the intermediate shaft 50.

[0021] A flange portion 64 extending radially outward is integrally formed at the end of the outer ring 52a of the first joint 52 on the differential gear 26 side. A connecting member 66 having a diameter larger than that of the end portion and having the same diameter as the flange portion 64 is integrally formed at the end of the differential shaft portion 40 on the drive shaft 28 side. The connecting member 66 may be regarded as a part of the differential gear 26 or as a first member integrally connected to the differential gear 26. The flange portion 64 may be regarded as a part of the drive shaft 28 or as a second member integrally connected to the drive shaft 28.

[0022] The power transmission device 16 is provided in the power transmission path between the differential gear 26 and the drive wheel 14 (the drive shaft 28 is also the same in this embodiment), and further includes an elastic member 70 sandwiched between the connecting member 66 and the flange portion 64. The elastic member 70 is, for example, rubber, a resin coating material, or the like. The elastic member 70 is clamped by bolts 72 while being sandwiched between the connecting member 66 and the flange portion 64.

[0023] Figure 3 illustrates an example of a coupling structure between the differential gear 26 and the drive shaft 28, different from the coupling structure shown in Figure 2. Figure 3(a) shows an example of a coupling structure that separates the fastening function and the damping function. Figure 3(b) shows an example of a coupling structure that can maintain axial force using a spring. Figure 3(c) shows an example of a coupling structure that can prevent pinching and loosening and protect the internal structure using a plate.

[0024] In Figure 3(a), the elastic member 80 is a rubber, resin coating material, etc., sandwiched between the first plate 82 and the second plate 84 by vulcanization, compression, or adhesive. The elastic member 80, the first plate 82, and the second plate 84 are formed as a single plate and are fastened together by bolts 86, 88, etc., while sandwiched between the differential gear 26 and the drive shaft 28.

[0025] In Figure 3(b), the elastic member 90 is sandwiched between the differential gear 26 and the drive shaft 28 together with the spring 92 and is fastened by a bolt 94. The elastic member 90 is made of, for example, rubber, a resin coating material, etc.

[0026] In Figure 3(c), the elastic member 100 is sandwiched between the differential gear 26 and the drive shaft 28, and is held together with the differential gear 26 and the drive shaft 28 by the plate 102. The elastic member 100, the differential gear 26, and the drive shaft 28 are fastened together by bolts 104 or the like while sandwiched between the plate 102. The elastic member 100 is made of, for example, rubber, a resin coating material, or the like.

[0027] As described above, this embodiment further includes an elastic member 70 provided in the power transmission path between the differential gear 26 and the drive wheel 14. The elastic member 70 is a member sandwiched between the connecting member 66 and the flange portion 64. This suppresses the transmission of vibrations caused by the thrust force of the drive shaft 28. Therefore, it is possible to reduce vehicle floor vibrations caused by the thrust force of the drive shaft 28.

[0028] Although embodiments of the present invention have been described in detail above with reference to the drawings, the above-described embodiment is merely one example, 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 Symbols]

[0029] 12: Power source 14 (14L, 14R): Drive wheels 16: Vehicle power transmission device 26: Differential gear 28 (28L, 28R): Drive shaft 64: Flange section (second member) 66: Connecting member (first member) 70: Elastic member

Claims

[Claim 1] A vehicle power transmission device comprising a differential gear that distributes power from a power source to the left and right drive wheels, and left and right drive shafts provided in the power transmission path between the differential gear and the drive wheels, A vehicle power transmission device characterized by further comprising an elastic member sandwiched between a first member provided in the power transmission path and integrally connected to the differential gear or the differential gear, and a second member integrally connected to the drive shaft or the drive shaft.

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