JP2958998B2 - Front wheel drive system for front and rear wheel drive motorcycles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front wheel drive device for a front and rear wheel drive motorcycle.

[Conventional technology]

Motorcycles have an engine that drives the rear wheels,
There are front and rear wheel drive motorcycles in which the front wheels are driven by an engine. The front and rear wheel drive motorcycle has an advantage that it can be driven by the front and rear wheels and run smoothly even in a place where the road surface is slippery.

[Problems to be solved by the invention]

However, since the front fork with the front wheels attached is turned by the steering wheel for steering, the structure is complicated and heavy to drive the front wheels so as not to hinder the steering, and the weight of the front fork increases and the unsprung weight There is a disadvantage that the cushion performance is inferior due to the increase. For example, Japanese Patent Application No. 58-167282, Shokai 6
See 3-173895.

In view of the foregoing, an object of the present invention is to provide a front-wheel drive device for a front-rear-wheel drive motorcycle that can drive a front wheel with a pair of drive shafts and a driven shaft, and can reduce unsprung weight and improve cushioning performance. .

[Means for solving the problem]

The present invention provides an upper drive shaft (20) and a lower hollow driven shaft (23) on one side of the left and right front forks (front fork 8, outer tube 11) of the steering shaft (9). Are provided so as to rotate integrally with each other and to slide in the vertical direction in accordance with expansion and contraction of the front forks (8, 11) in a vertical arrangement parallel to the front forks (8, 11). ) Is rotationally driven by an engine (1) on a frame (2) side, and a driven shaft (23) is an engine (1) in a front wheel drive device of a front-rear wheel drive motorcycle that rotationally drives a front wheel (26) on a steering side. ) Is disposed on one side of the frame (2), and the drive shaft (20) and the driven shaft (23) are disposed on the front forks (8, 11) on the drive shaft (3) side. Steer At the top of the ring,
A horizontal counter shaft (16) driven by the engine (1) is provided, and a bevel pinion (18) and a bevel gear (19) mesh with the counter shaft (16) and the drive shaft (20), respectively. The bevel pinion (24) and bevel gear (2) are mounted on the axle (29) of the driven shaft (23) and the front wheels (26), respectively.
5) are provided so as to mesh with each other, and the counter shaft (1
6) Bevel pinion (18) is connected to drive shaft (2
The bevel gear (25) of the axle (29) is disposed above and inside (on the steering shaft 9 side) with respect to the bevel gear (19) of the driven shaft (23) with respect to the bevel pinion (24) of the driven shaft (23). It is configured to be disposed on the lower side and inside (front wheel 26 side).

Further, in the present invention, a constant velocity joint (12) is provided below the steering shaft (9) so as to connect the lateral input shaft and the lateral output shaft to be freely refracted in accordance with the steering of the steering. The shaft and the lateral output shaft are arranged so as to cross from one side to the other with respect to the steering shaft (9), and a lateral rotation transmitting device (rotational difference absorbing and torque distributing device 7) is provided on the front side of the frame (2). Is provided so as to traverse from one side to the other with respect to the steering shaft (9), and one side of the lateral rotation transmission device (7) is connected to the drive shaft (3), and the lateral rotation transmission device (7) is provided. The other side is connected to the horizontal input shaft, and the counter shaft (16) is connected to the horizontal output shaft.

[Action]

The rotational drive of the front wheel (26) on the steering side is performed by the engine (1) on the frame side by the drive shaft (3), the lateral rotation transmission device (7), the lateral input shaft, and the constant velocity joint (1).
2), lateral output shaft, counter shaft (16), bevel pinion (18), bevel gear (19), drive shaft (2
0), driven shaft (23), bevel pinion (2
4), via bevel gear (25), axle (29). Also, as the front fork (8, 11) expands and contracts, the upper drive shaft (20) and the lower driven shaft (2
3) and slide, and according to the steering of the steering,
The left and right horizontal input shafts and the horizontal output shaft of the constant velocity joint (12) are bent.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The engine 1 is mounted on the lower front part of the frame 2. The engine 1 has a built-in clutch for connection / disconnection operation and a multi-stage gear transmission, and a rear chain 4 on a drive shaft 3 on the left side thereof.
The rear wheel 5 is connected to the rear wheel 5, and the rear wheel 5 is driven and rotated. On the other hand, the drive shaft 3 is connected via a front chain 6 to an input shaft on the left side of a rotation difference absorbing and torque distribution device 7. The rotation difference absorbing and torque distributing device 7 is arranged so as to cross the lower front part of the frame 2 (rear lower part of the steering shaft 9) from left to right and to the left (drive shaft 3 side).
Is provided with an input shaft, and an output shaft is provided on the right side. A steering shaft 9 to which the left and right front forks 8 are attached is mounted on a head pipe 10 at the front end of the frame 2 so that the steering shaft 9 can be rotated and steered. Outer tubes 11 are inserted and connected to the lower portions of the left and right front forks 8 so that they can expand and contract to cushion. A constant velocity joint 12 is disposed directly below the steering shaft 9, and the right side horizontal input shaft of the constant velocity joint 12 is connected to a right output shaft of the rotation difference absorbing and torque distribution device 7 by a connection chain 13. The right lateral input shaft and the left lateral output shaft of the constant velocity joint 12 are connected to the steering 9.
Are arranged so as to traverse from the right side to the left side, and when the steering wheel is steered, they are bent.

An upper gear case 15 is provided on the lower left side of the under bracket 14 of the front fork 8 (on the side of the drive shaft 3), and a horizontal output shaft on the left side of the constant velocity joint 12 is supported.
A horizontal counter shaft 16 is mounted on the front side thereof, and the horizontal output shaft on the left side of the constant velocity joint 12 and the counter shaft 16 are connected by a pair of gears 17. The counter shaft 16 is a bevel pinion 18 and bevel gear 19, and a drive shaft 20
Connect to The bevel pinion 18 is a bevel gear
It is arranged above and to the right of 19 (inside, that is, on the steering shaft 9 side).

The outer tube 11 on the left side (drive shaft 3 side)
A shaft housing 21 is provided integrally on the front side, and a lower gear case 22 is provided on the lower front side. Driven shaft 23
Is hollow, and has a lower portion of the drive shaft 20 inserted and connected so as to be rotatable integrally and slidably. Driven shaft
The reference numeral 23 is inserted into the shaft housing 21 and is rotatably mounted on a shaft by a bearing. The drive shaft 20 and the driven shaft 23 are arranged parallel to one front side of the front fork 8, and the driven shaft 23 moves with the expansion and contraction of the outer tube 11. Since the driven shaft 23 is hollow, the weight on the unsprung side can be reduced, and the cushion performance can be improved. Also, drive shaft 20
In addition, the length of the driven shaft 23 can be made short and light, and the driven shaft 23 can smoothly transmit rotation while moving with the outer tube 11. Bevel pinion 24 at the lower end of driven shaft 23 to bevel gear 25
The bevel gear 25 is connected to a lateral axle 29 of a front wheel 26 by a dog 27. The bevel gear 25 is disposed below and on the right side (inside, that is, on the front wheel 26 side) with respect to the bevel pinion 24. The front wheel 26 is rotatably mounted on a lower gear case 22 of the left outer tube 11 and a boss 28 provided on the right outer tube 11 using an axle 29.

The center axes of the drive shaft 20 and the driven shaft 23 pass through the center axis of the axle 29 of the front wheel 26 and are arranged in a plane parallel to the steering shaft 9. The center axis of the front fork 8 is disposed parallel to the center axis of the drive shaft 20, the driven shaft 23 and the center axis of the steering shaft 9 in the front-rear direction. 9 as close as possible.

Also, the upper gear case 15 and the lower gear case 22
Is an oil bath filled with a fixed amount of lubricating oil. The lower end of the upper gear case 15 and the upper end of the left outer tube 11 and the upper end of the shaft housing 21 are connected by a cylindrical boot 30 with an elastic body, and the boot 30 connects the left front fork 8 and the drive shaft 20 part. To cover it. The boot 30 is provided with a small hole so that it can breathe. Accordingly, since the drive shaft 20 and the front fork 8 on one side are accommodated in one boot 30, the mounting can be simplified, the number of parts can be reduced, the weight can be reduced, the inertia around the steering wheel can be reduced, and good handling can be achieved.

The rotation of the front wheels 26 on the steering side is driven by the engine 1 on the frame 2 side by the drive shaft 3, the front chain 4, the rotation difference absorbing and torque distribution device 7, the connection chain 13,
Constant velocity joint 12, gear 17, counter shaft 16, bevel pinion 18, bevel gear 19, drive shaft 20, driven shaft 23, bevel pinion 24, bevel gear 2
5, via dog 27, axle 29.

〔The invention's effect〕

Since the present invention is configured as described above, the driving of the front wheels on the steering side can be performed by the engine on the frame side while minimizing the influence on steering, expansion and contraction of the front fork, maneuverability, and the like. it can.

[Brief description of the drawings]

Fig. 1 shows an embodiment of the present invention. Fig. 1 is a partially longitudinal front view of a front fork portion, Fig. 2 is a longitudinal side view of the same part, Fig. 3 is an overall plan view, and Fig. 4 is a side view thereof. ,. 8 ... front fork, 11 ... outer tube, 14 ... under bracket, 15 ... upper gear case, 16 ... counter shaft, 20 ... drive shaft, 21 ... shaft housing, 22 ... lower gear case, 23 …… Driven shaft, 24 …… Bevel pinion, 25 …… Bevel gear,
26 ... front wheels, 30 ... boots.

Claims (1)

(57) [Claims] An upper drive shaft and a lower hollow driven shaft are integrated with one another on one side of a left and right front fork of a steering shaft of a steering in a vertical arrangement in parallel with the front fork. The drive shaft is rotated by an engine on the frame side, and the driven shaft is rotated before and after rotating the front wheel on the steering side. In the front wheel drive device for a wheel drive motorcycle, a drive shaft of the engine is disposed on one side of the frame, the drive shaft and the driven shaft are disposed on the front fork on the drive shaft side, and an upper part of the steering wheel. Is provided with a horizontal counter shaft rotationally driven by the engine, A bevel pinion and a bevel gear are provided on the drive shaft and the drive shaft, respectively, and a bevel pinion and a bevel gear are provided on the lateral axle of the driven shaft and the front wheel, respectively. The bevel pinion of the counter shaft is disposed above and inside the bevel gear of the drive shaft, and the bevel gear of the axle is below and inside the bevel pinion of the driven shaft. A constant velocity joint is provided below the steering shaft so as to connect a lateral input shaft and a lateral output shaft so as to be able to bend freely in accordance with the steering of the steering. The output shaft is located so as to cross from one side to the other with respect to the steering shaft. A lateral rotation transmission device is provided on the front side of the frame so as to cross from one side to the other with respect to the steering shaft, and one side of the lateral rotation transmission device is connected to the drive shaft, The other side of the lateral rotation transmitting device is connected to the lateral input shaft, and the counter shaft is connected to the lateral output shaft.