JPS6099727A - Shaft drive device for car - Google Patents

Abstract

PURPOSE:To facilitate backlush adjusting work, in a shaft drive device for automatic bicycle, by pressing a damper cam resiliently against an inverted bevel gear while securing the drive shaft housing through an adjusting seam to the crank case. CONSTITUTION:Gear shift 20, inverted bevel gear 21, thrust washer 26 and shock torque buffer 30 are sub-assembled through a ball bearing 22 in a drive shaft housing 43. An adjusting seam 44 of such depth as to provide proper backlush between the assembled bevel gears 14, 21 is held between the rear face 42b of gear chamber 42 and the fixing face 43b of drive shaft housing 43 then fixed through fixing bolt 45 to the crank case 40 and gear shaft 41. The dimension between the drive bevel gear 14 and planar section 40b is adjusted by means of said seam 17.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a shaft drive device for transmitting power from an engine to a rear wheel in a vehicle such as a motorcycle or a tricycle.

(Prior Art) A conventional shaft drive device of this kind, namely, a partition wall that is substantially parallel to the flat part on the left and right sides of the rear part of the engine crankcase is provided inside the flat part, and a partition wall that is substantially parallel to the flat part is provided in the flat part, and a half-bottomed cylindrical shape is provided in the flat part. A gear housing is fixed to one side of the rear part of the crankcase and the gear housing forms a gear chamber having an opening on the rear side, and a front end of a cylindrical drive shaft housing extending rearward is connected to the opening, and A drive axle having a transverse axis is rotatably supported by the partition wall, a drive bevel gear is fixed to one end of the drive axle protruding into the middle gear chamber, a rear end is connected to the drive shaft housing, and a front end is connected to the crankcase. A gear shaft rotatably supported by the gear housing is provided in the gear chamber orthogonal to the drive axle, a driven bevel gear that meshes with the drive bevel gear is rotatably provided on the gear shaft, and the gear shaft is provided with a driven bevel gear that meshes with the drive bevel gear. An example of a damper cam in which the cam surface at one end of the damper cam, which is movable only in the axial direction, is pressed against the cam surface of the driven bevel gear to buffer the impact torque between both the bevel gears is shown in FIG. ,
In this example, the backlash between the driving bevel gear 1 and the driven bevel gear 2 was adjusted as follows. That is, the gear shaft 3 is attached to the ball ring 8 fixed to the drive shaft housing 7 by the nut 6 via the special expansion spacer 4 engaged with the stepped portion 3a, the spline coupling 5, and the washer 9. By adjusting the tightening, the axial position of the driven bevel gear 2 together with the gear shaft 3 is slightly moved to adjust the backlash. However, in the above conventional technology, the expansion spacer 4, the spline coupling 5, and the nut 6 are used to adjust the backlash.
In particular, the expansion spacer 4 needs to absorb the adjustment deflection by the nut 6 and generate a nearly constant reaction force within the adjustment range, making it an expensive special component. There were drawbacks such as the need to carry out the process on the main line of vehicle assembly.

(Objectives of the Invention) It is an object of the present invention to solve the above-mentioned difficulties by making the backlash adjustment work easier than before in this type of shaft drive device, and simplifying the structure.

(Structure of the Invention) In order to achieve the above-mentioned object, the present invention provides a shaft drive device for this type of vehicle, in which an outer ring of a ball bearing is fixed to the front part of the drive shaft housing, and a flange provided at the rear part of the gear shaft is fixed to the outer ring of a ball bearing. The gear shaft is fixed to the inner ring of the ball bearing by a spring retainer screwed into a threaded portion on the outer circumference of the shaft, and a compression spring is provided between the spring retainer and the damper cam to press the damper cam against the driven bevel gear. The elastic force of the compression spring applied to the driven bevel gear is supported by a thrust washer installed in a groove at the front end of the gear shaft, and the rear end of the gear shaft is connected to a drive shaft that transmits power to the rear wheels. The invention is characterized in that a mating spline is integrally provided, and the drive shaft housing is fixed to the crankcase and the gear housing via an adjustment shim.

(Effects of the Invention) The present invention configured as described above does not require special parts such as expansion spacers, and the gear shaft is fixed to the ball bearing by the spring retainer, and the rear end of the gear shaft is directly engaged with the drive shaft. The number of parts has been reduced, and after the gear shaft and the parts attached to it are attached to the drive shaft housing on the sub-assembly line, the dimensions of the drive shaft housing mounting surface and the reference surface of the driven bevel gear are measured. Then, it is attached to the main line upstream rank case and gear housing via a shim of a predetermined thickness (only one is required, so the assembly work is easy.

(Embodiment) FIG. 1 shows one embodiment of the present invention, showing the rear half of the engine to the drive shaft. Power from a crankshaft (not shown) at the front of the engine is transmitted to a drive axle 13 via a clutch 10, a main axle 11, and a transmission 12. A gear housing 41 is fixed to one side (left side in the figure) of the crankcase 40, and a gear chamber 42 with an open rear side is formed by both of them, and a drive shaft housing 43 extending rearward is fixed thereto. A gear shaft 20 is rotatably supported in the gear chamber 42 so as to be orthogonal to the drive axle 13, and its axial position is determined by being screwed into a ball bearing 22 fixed to a drive shaft housing 43 by a spring retainer 33. The driven bevel gear 21 at the front end of the gear shaft 20 is an impact torque buffer device 30.
The drive bevel gear 14 is connected to the gear shaft 20 through the drive axle 13 and meshes with the drive bevel gear 14 fixed to the left end of the drive axle 13.

Backlash adjustment of the umbrella gear 14.21 is performed by an adjustment shim 44 interposed between the drive shaft housing 43, the crankcase 40, and the gear housing 41.

On the rear left side of the crankcase 40 of an engine supported on the body of a vehicle such as a motorcycle or three-wheeled vehicle, there is provided a plane part 40b parallel to the vertical plane in the longitudinal direction of the vehicle body, and a partition wall 4 approximately parallel to the plane part is provided inside the plane part 40b. Set ゜a. A drive axle 13 having an axis transverse to the vehicle body is pivotally supported by a ball hair ring 16 with its left side penetrating the bulkhead 40a;
The ball bearing 16 is positioned in the axial direction by a shim 17, and is fixed to the partition wall 40a by a holding plate 18. A gear housing 41 in the shape of a cylinder with a half-split bottom is bolted (not shown) to the crankcase 40 so as to cover the flat part 40b, and a gear chamber having an opening 42a on the rear side is formed by the rear left side of the gear housing 41 and the crankcase 40. form 42. The opening 42a has a cylindrical shape with the plane portion 40b as a symmetrical plane and is provided across the gear housing 41 and the crankcase 40, and the rear surface 42b forms one plane. Opening 42
A cylindrical portion 43d at the front end of a cylindrical drive shaft housing 43 extending rearward is fitted into the cylindrical portion 43a, and fixed with a mounting bolt 45.

At the front of the gear chamber 42, a cylindrical surface 42c having a symmetrical plane with the plane portion 40b is provided across the crankcase 40 and the gear housing 41, and supports the ball bearing 23 to prevent it from slipping out. On the other hand, the outer ring of the ball bearing 22 is fixed within the cylindrical portion 43d by a ring nut 24. gear shaft 2
0 is pivotally supported by a ball ring 23 via a rotatably provided driven bevel gear 21, and the rear end of the ball ring 22 is supported by a spring retainer 33 screwed onto the flange 20a and threaded portion 20b. Fixed to the inner ring,
It is pivotally supported by a hall bearing 22. Thus, the gear shaft 20 is orthogonal to the drive axle 13, and is axially positioned and supported by the drive shaft housing 43.

The impact torque buffering device 30 between the gear shaft 20 and the driven bevel gear 21 includes a damper cam 31, a compression spring 32, and a spring retainer 33.

The damper cam 31 is connected to the spline 20c of the gear shaft 20.
The coil is spline-coupled so as to be slidable in the axial direction, and has an inclined cam surface 31a that forms a mountain shape along the circumference on the front end surface of the coil. A compression spring 32 such as a spring applies pressure to the cam surface 21& of the driven bevel gear 21. The force of the compression spring 32 applied to the driven bevel gear 21 is supported by the two-split thrust washer 2G engaged with a groove at the front end of the gear shaft 20. Thus, the driven umbrella gear 21 is connected to the gear shaft 2.
0 and the drive shaft housing 4
Positioned relative to 3. If an impact torque occurs for some reason during power transmission between the engine and the rear wheels, the cam surface 21a.

Since an impulsive thrust occurs between 31a and 31a, the compression spring 32
flexes to absorb the impact torque.

A driving bevel gear 14 is fixed to the left end of the drive axle 13 protruding into the gear chamber 42 with a nut 15, and is meshed with the driven bevel gear 21. A spline 20d is integrally formed on the rear end of the gear shaft 20, and engages the front end of the drive shaft 25. ).

When assembling, first install the drive shaft housing 43.
After sub-assembling the gear shaft 20, driven bevel gear 21, thrust washer 26, and impact torque buffer 30 via the ball bearing 22, the flange mounting surface 43b of the drive shaft housing 43 and the reference surface of the driven bevel gear 21, for example 21b, are sub-assembled. Measure the dimensions between. According to the measured dimensions, an adjustment shim 44 having a thickness such that the backlash between the assembled umbrella gears 14 and 21 is an appropriate value is selected, and this is adjusted between the rear surface 42b of the gear chamber 42 and the drive shaft housing 43. The drive shaft housing 43 is mounted between the mounting surfaces 43b and the crankcase 40 and the gear shaft 41 with the mounting bolts 46 via the flange 43a.
Attach to. Note that the dimension between the drive bevel gear 14 and the flat portion 40b is adjusted by the shim 17 if necessary.

(Effects of Embodiment) In the above embodiment, the spring retainer 33 and the tightening member for fixing the gear shaft 22 to the ball bearing 22 are combined, and the spline 20 is integrally attached to the rear end of the gear shaft 20.
Since the number of parts is reduced, and there are no special parts used, the cost of parts can be reduced. In addition, the time-consuming umbrella gear 14.21
Since the backlash between the parts can be adjusted on the sub-assembly line, the effort required for assembly can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a horizontal cross-sectional view showing an embodiment of the present invention, and FIG. 2 is a horizontal cross-sectional view of essential parts showing an example of a conventional product. Explanation of symbols 13... Drive axle, 14... Drive bevel gear,
20... Gear shaft, 20a... Flange, 20
b... Threaded portion, 21... Driven bevel gear, 21a... Race cam surface, 22... φ ball bearing, 25... Drive shaft, 26... Thrust washer, 31...
- Damper cam, 31a... cam surface, 32... compression spring, 33... spring retainer, 40... crankcase, 40a... bulkhead, 40b... flat part, 4
1... Gear housing, 42... Gear chamber, 42a.
...Opening, 43...Drive shaft housing, 4
4... Adjustment shim. Applicant Yamaha Motor Co., Ltd. Agent Patent Attorney Teru Hase - (1 other person)

Claims (1)

[Claims] A partition wall is provided inside the flat part on one of the left and right sides of the rear part of the engine crankcase, and is substantially parallel to the flat part, and a gear housing in the form of a cylindrical half-split bottom is fixed to the flat part. A gear chamber having an opening on the rear side is formed by the side and the gear housing, a front end of a cylindrical drive shaft housing extending rearward is connected to the opening, and a drive axle having a transverse axis is freely rotatable by the partition wall. A drive bevel gear is fixed to one end of the drive axle protruding into the middle gear chamber, and a rear end is rotatably supported by the drive shaft housing and a front end is rotatably supported by the crankcase and the gear housing. A driven bevel gear which is provided perpendicularly to the drive axle in the gear chamber and which meshes with the drive bevel gear is rotatably provided on the gear shaft, and one end of a damper cam is provided on the gear shaft so as to be movable only in the axial direction. In a vehicle such as a motorcycle or a tricycle, the outer ring of a ball bearing is fixed to the front part of the drive shaft housing in a vehicle such as a motorcycle or a tricycle in which a cam surface is pressed against a cam surface of the driven bevel gear to buffer impact torque between the bevel gears. The gear shaft is fixed to the inner ring of the ball hair ring by a flange provided at the rear of the gear shaft and a spring retainer that is screwed into a threaded portion on the outer periphery of the gear shaft, and a space between the spring retainer and the damper cam is fixed to the inner ring of the ball hair ring. A compression spring is provided to press the damper cam against the driven bevel gear, and the elastic force of the compression spring applied to the driven bevel gear is supported by a thrust washer installed in a groove at the front end of the gear shaft. A vehicle characterized in that the rear end of the shaft is integrally provided with a spline that engages with a drive shaft that transmits power to the rear wheels, and the drive shaft housing is fixed to the crankcase and the gear housing via an adjustment shim. shaft drive device.