JPH0719983Y2 - Rear wheel support device for motorcycles - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a rear wheel support device for a motorcycle.

[Prior Art] Japanese Examined Patent Publication No. 61-52338 discloses a shaft drive type two-wheeled vehicle that supports both rear wheels in order to absorb rotational torque fluctuations and smoothly rotate the rear wheels. The one provided with a damper is shown. In this structure, a driven flange that is rotatably supported around the rear wheel axle is provided between the rear wheel and the gear case, and this driven flange is engaged with a damper provided on the rear wheel hub side.

On the other hand, in a cantilever type in which a rear wheel is supported on one side of a rear end portion of a rear swing arm, one end of a rear wheel axle, which is a drive shaft, is attached to the rear swing arm as shown in Japanese Patent Laid-Open No. 61-89189. The chain sprocket is supported on the outside of the arm through a damper, and the rear wheel hub is integrally rotatably attached to the other end of the rear swing arm.

[Problems to be Solved by the Invention] By the way, the rear wheel axle is generally required to have high rigidity, and the damper is required to have a large diameter to increase the capacity.

However, in the above-mentioned double-supported type, since the rear wheel axle is lengthened by the provision of the driven flange, it is necessary to further improve the rigidity, and the number of parts and the weight are increased.

On the other hand, in the case of the cantilever type, since the damper is on the outer side, the appearance is likely to be adversely affected. Further, if the damper is moved inward of the vehicle body, the rear wheel axle becomes longer accordingly. Moreover, since the rear wheel axle is a rotating drive shaft, it is also necessary to pay attention to the positional relationship between the pair of left and right bearings provided to support both ends of the rear wheel axle and the damper.

An object of the present invention is to provide a rear wheel support device for a motorcycle that solves the above problems.

[Means for Solving the Problems] In order to solve the above problems, a rear wheel support device for a motorcycle according to the present invention includes a gear case provided at a rear end portion of a rear swing arm, and a rear end of a drive shaft. A pinion gear, a ring gear, and a ring gear shaft that rotatably supports the ring gear are accommodated, a large-diameter damper accommodating portion facing the inside of the gear case is integrally formed around the ring gear shaft, and the ring gear is engaged in the damper accommodating portion. Of the ring gear shaft that fits the mating damper and extends one of the bearings provided in the gear case for bearing both ends of the ring gear shaft from the damper accommodating portion so that the rear wheel hub is integrally rotatably mounted. It is characterized in that it is arranged on the outer periphery of one end.

[Operation of the Invention] When the ring gear rotates, the rotational torque fluctuation is absorbed by the damper and transmitted to the ring gear shaft, so that the rear wheel rotates smoothly. At this time, the ring gear shaft has a large diameter due to the formation of the damper accommodating portion. Further, the bearings that support both ends of the ring gear shaft sandwich the damper therebetween, and the span between the bearings becomes long. Therefore, the rigidity of the ring gear shaft is improved. Further, since one of the bearings is arranged between the damper accommodating portion and the rear wheel hub, it is possible to freely expand the damper in the radial direction, and the damper is located inside the gear case and cannot be seen from the outside.

[Embodiment] FIGS. 1 and 2 show an embodiment of the present invention. FIG. 1 shows a shaft-drive type motorcycle to which the present invention is applied, 1 is a front wheel, 2 is a body frame, 3 is an engine, 4
Is a rear swing arm. The rear swing arm 4 is of a cantilever type, and a rear wheel 6 is supported on one side of a ring gear shaft 5 (rear wheel axle) which is a drive shaft rotatably supported at a rear end portion thereof.

FIG. 2 shows the details of the rear wheel support portion. A gear case body 7 is integrally formed at the rear end portion of the rear swing arm 4, and a pinion gear 9 formed at the rear end of the pinion gear shaft 8 is provided therein. It is housed. A ring gear 10 that meshes with the pinion gear 9 is rotatably mounted around the ring gear shaft 5. A pin 11 is provided on the back surface of the ring gear 10 so as to project inward in the axial direction, and is engaged with a side surface of a rubber damper 13 via a collar 12 fitted to the projecting portion. The damper 13 is press-fitted into an annular recess 15 provided on the side surface of the damper accommodating portion 14. The damper accommodating portion 14 is provided in a large diameter portion integrally formed in the middle portion of the ring gear shaft 5 and faces the space inside the gear case body 7. Reference numeral 16 is a cover provided so as to be sandwiched between the outer side of the damper 13 and the back surface of the ring gear 10 so as to seal the recess 15, and by providing the cover 16, the durability of the damper 13 is improved. You can

A step portion 17 having a diameter smaller than that of the damper accommodating portion 14 is formed on the vehicle body center side of the damper accommodating portion 14, and the outer peripheral surface thereof is borne by a ball bearing 18 having a large diameter. The ball bearing 18 is fitted in a gear case cover 19 that covers the inner sides of the ring gear 10 and the damper accommodating portion 14.

A brake disc 20 of a rear wheel brake is attached to the end surface of the ring gear shaft 5 on the inner side of the vehicle body by a bolt 21. The rear wheel hub 22 is located on the brake disc 20
It is mounted with a wheel nut 24 via a hub mounting bolt 23 having one end attached to 17. Rear wheel hub 22 is bolt 21
Also serves as a retainer. By attaching the brake disc 20 to the ring gear shaft 5 side, it becomes unnecessary to attach and detach the brake disc 20 when attaching and detaching the rear wheels.

In addition, the outer end of the ring gear shaft 5 has a gear case 7
Is supported via a small diameter ball bearing 25.

Next, the operation of this embodiment will be described. The driving force transmitted to the damper 13 through the pinion gear shaft 8, the pinion gear 9, the ring gear 10, the pin 11 and the collar 12 is smoothed to the damper accommodating portion 14 because the damper 13 absorbs the rotational torque fluctuation. Transmitted, ring gear shaft 5
Is driven. As a result, the rear wheel hub 22 integrated with the ring gear shaft 5, that is, the rear wheel 6, is driven smoothly.

At this time, the rear wheel hub 22 has the step portion 17 of the ring gear shaft 5.
Since it is attached to the gear case cover 19, it can be arranged close to the gear case cover 19. Therefore, the ring gear shaft 5 is shortened, and the damper accommodating portion 14 is integrally formed to have a large diameter. In addition, by arranging the ball bearing 18 side by side with the damper accommodating portion 14 between the rear wheel hubs 22, the damper 13 is sandwiched between the ball bearings 18 and 25.
And the span between 25 and 25 increases. Therefore, the rigidity of the ring gear shaft 5 can be improved, and as a result, the meshing of the ring gear 10 with the pinion gear 9 can be maintained well.

Further, by arranging the ball bearing 18 and the damper housing portion 14 side by side, it is easy to make the damper housing portion 14 large in the radial direction, so that the capacity of the concave portion 15 housing the damper 13 can be easily expanded, and the damper 13 can be expanded. Can contribute to the large capacity of.
Moreover, the ball bearing 18 and the damper 13 can be compactly housed in the gear case. Moreover, since the damper 13 is accommodated inside the gear case surrounded by the gear case main body 7 and the gear case cover 19, it is hidden from the outside. Therefore, even if the damper 13 is provided in the cantilever type rear wheel support structure, it is possible to prevent the appearance from being adversely affected.

The present invention is not limited to the cantilever type of the above embodiment, but can be applied to a both-end type motorcycle.

[Advantage of the Invention] The present invention accommodates a damper that engages with a ring gear in a gear case, forms a large diameter damper accommodating portion on a ring gear shaft, and mounts a bearing between the damper accommodating portion and the rear wheel hub. Since the ring gear shaft is arranged, the driven flange as in the conventional two-wheeled motorcycle can be omitted, and the ring gear shaft can be made short and thick, and the bearing span for the ring gear shaft can be made long. As a result, the ring gear shaft has high rigidity, and the rigidity of the rear wheel support portion is improved. Moreover, it became easy to expand the damper in the radial direction to increase its capacity.

When the present invention is applied to a cantilever type motorcycle, the damper can be arranged inside the vehicle body without adversely affecting the appearance.

[Brief description of drawings]

1 and 2 show an embodiment, FIG. 1 is an external view of a motorcycle, and FIG. 2 is a sectional view of a main part. (Description of symbols) 4 ... Rear swing arm, 5 ... Ring gear shaft, 6 ... Rear wheel, 7 ... Gear case body (part of gear case), 10 ... Ring gear, 13 ... Damper, 14 ... Damper Housing, 18 …… Ball bearing, 19 …… Gear case cover (part of gear case), 22 …… Rear wheel hub, 25 ……
ball bearing,.

Claims (1)

[Scope of utility model registration request] 1. A gear case provided at the rear end of a rear swing arm accommodates a pinion gear and a ring gear at the rear end of a drive shaft, and a ring gear shaft rotatably supporting the ring gear, and a gear case is provided around the ring gear shaft. A large-diameter damper accommodating portion facing inward is integrally formed, and a damper that engages with the ring gear is further fitted in the damper accommodating portion, and a bearing provided on a gear case for bearing both ends of the ring gear shaft. A rear wheel support device for a motorcycle, wherein one of the two is disposed on an outer periphery of one end of a ring gear shaft that extends from a damper accommodating portion and integrally mounts a rear wheel hub.