JPS6152338B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing device for sealing a spline engagement portion between a driven flange that drives a wheel and a final driven member driven by a bevel gear or the like in a shaft drive type motorcycle or the like. be.

The wheel drive section of a shaft drive type motorcycle is constructed as shown in Fig. 4, and has an axially extending portion 51a on a gear shaft 51 which is the final driven member and includes a bevel gear driven by a propeller shaft via a bevel gear. provided, the inner diameter part 51 of this
b is provided with an inner diameter spline portion 52, and a driven flange 53 that transmits power to the hub via an elastic body.
An axially long cylindrical part 53a is provided at the base of the cylindrical part 53a, and an outer diameter spline part 5 is provided at an axially intermediate outer diameter part 53b of the cylindrical part 53a.
4 are provided, and these spline portions 52 and 54 are engaged to transmit power to the gear shaft 51 to the driven flange 53. By the way, since there is a gear meshing part around this area and it is lubricated, an oil seal is required, so conventionally the spline part 5 is
An O-ring 55 is interposed between the ends of the driven flange 53 between the spline portion 54, and a ring-shaped recess 5 is provided in the outer diameter portion 53b of the cylindrical portion on the other end of the spline portion 54 in the axial direction.
3c, and an O-ring 56 is interposed therebetween to seal between it and the inner diameter portion 51b of the shaft 51.

In the above conventional means, since the spline parts 52 and 54 are sealed with O-rings on the outside of both ends in the axial direction, the length L between the driven flange and the end of the shaft engaging part becomes large. In other words, the bearing position of the wheel approaches the center of the wheel, which means that it is necessary to increase the strength and rigidity of the hub, axle, bearing, etc. It is necessary to move the driven flange away from the center of the wheel, and if the driven flange is moved to the left in the figure, the axle support portion will become larger in the axial direction.This is caused by the oil seal, so improvement of this is desired.

The present invention has been made in response to the above, and its object is to extend a cylindrical holder from the inner diameter part of the gear shaft so as to wrap around the inner diameter part of the driven flange cylinder part, and to connect the outer diameter part of the cylindrical holder to the driven flange cylinder part. A sealing member is interposed between the inner diameter portions of the cylindrical portion, and the length between the sealing member between the engaging portions and the sealing member is shortened as much as possible, thereby reducing the overall axial length and reducing the length of the drive portion. It is an object of the present invention to provide a sealing device for a wheel drive part of a shaft drive type motorcycle, etc., which is compact in the axial direction and allows wheel bearings to be placed outward.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic side view of a motorcycle 1, in which a front fork 5 that supports a front wheel 4 is supported in a freely steerable manner via a head tube 3 at the front end of a frame 2.
An engine 6 is mounted on the front lower part of the frame 2, a fuel tank 7 is mounted on the upper part, and a seat 8 is arranged behind the fuel tank 7. A rear fork 10 extends from the rear lower part of the frame to support a rear wheel 9.

FIG. 2 is an enlarged cross-sectional view of the oil seal portion according to the present invention, and FIG. 3 is an expanded cross-sectional view of the wheel drive portion.

In FIG. 3, reference numeral 11 denotes a case provided at one rear end of the rear fork 10. In the front part of the case 11, an input shaft 13 having a bevel gear 12 is provided in the front-rear direction, and the input shaft 13 has a bearing 14 and an oil It is supported and sealed by a seal 15. An axle 16 is horizontally mounted behind the bevel gear 12 in a direction perpendicular to the axial direction of the bevel gear 12, and one end of the axle 16 is connected to the outside of the case 11 with a nut 17, and the other end is connected to the rear end of the other rear fork 10A. It is worn.

A sleeve-shaped gear shaft 18, which serves as the final driven member, is loosely connected to the case side periphery on the axle 16.
one end in the axial direction is rotatably supported by a bearing 19 interposed between the small diameter outer diameter portion 18a of the tip portion,
An oil seal 20 is interposed on the outside of this. A spline portion 21 is provided on the outer periphery of the large diameter intermediate portion of the gear shaft 18, and a spline portion 21 is provided on the inner diameter portion of the final bevel gear 22 on the driven side.
The gear 22 meshes with the gear 12, and the gear shaft 18 is driven by the output of a propeller shaft (not shown). A large-diameter journal portion 23 is provided further axially inside the spline portion 21 of the shaft 18, and a bearing 25 is interposed between the journal portion 23 and the opening of a cover 24 that covers the axial inside of the case 11. An oil seal 26 is interposed inside the bearing 25 in the axial direction.

A hub 9a of the rear wheel 9 is located at the axially intermediate portion of the axle 16.
is rotatably supported by two bearings 27, 27 spaced apart in the axial direction, and a recess 9b is provided on the case side of the hub 9a, and a driven flange 28 interposed on the axle between the hub 9a and the shaft 18 is provided with a recess 9b on the case side of the hub 9a. The elastic body 29 and the recess 9b are engaged. At the base of the driven flange 28 is an axially outwardly extending sleeve portion 30.
On the other hand, the inner diameter part 31 of the journal part 23 is made large in diameter, the sleeve part 30 is fitted into the inner diameter part 31 in the axial direction, and the spline parts 30a and 3 are provided respectively.
1a engages both. Engaged spline part 3
Driven flange 2 at one axial end of 0a, 31a
Surrounding ring-shaped space S formed between the 8 side ends
An O-ring 32, which is an oil sealing material, is inserted inside to seal the driven flange and one end of the shaft. A small diameter inner diameter part 33 is provided axially outward of the large diameter inner diameter part 31 having the spline part 30a of the shaft 18, and the tip part 34a of the cylindrical holder 34 is connected to this by engaging or the like. is provided with a groove 35 that is concave in the inner radial direction and opens outward in the radial direction, and the groove 35 is formed in a ring shape.
Fit the O-ring 36 that forms an oil seal to the
The outer diameter portion of the ring 36 is brought into contact with the inner diameter portion 37 of the sleeve portion 30 of the driven flange 28. This allows the O-ring 36 to connect to the spline engagement portion 30.
a, 31a in the inner diameter direction, and comes into contact with the inner diameter portion 37 while wrapping therewith, thereby sealing this side. In this way, the O-rings 32 and 36 connect the spline engaging portions 30a,
31a and perform an oil seal.

In the drawings, numeral 38 indicates a brake panel, and numeral 39 indicates a brake arm.

As is clear from the above, according to the present invention, the spline portion of the gear shaft and the driven plate that are engaged with each other are sealed while being lapped at one end between the spline portions and in the inner diameter direction of the spline. The axial length of the wheel is shortened as much as possible, thereby increasing the axial distance between the wheel bearings, and thus making it possible to place the bearings as far as possible from the center of the wheel. It is no longer necessary to increase the strength and rigidity of the hub, bearings, etc. beyond what is necessary in the past.Secondly, the axial direction of the base of the gear shaft and driven flange has been shortened as much as possible, thereby making it possible to reduce the width of the case at the rear of the rear fork. It has many advantages, such as being able to be made smaller and more compact in the width direction.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic side view of a motorcycle, FIG. 2 is an enlarged sectional view of a seal portion, FIG. 3 is an expanded cross-sectional view of a wheel drive unit, and FIG. The figure is similar to FIG. 2 of the conventional example. In the drawings, 12 and 22 are gears, 18 is a final driven member, 28 is a driven flange, 30a and 31a are engaging portions, 32 and 36 are sealing materials, and 34 is a holder.

Claims (1)

[Claims] 1 an axle disposed in a direction perpendicular to a gear driven by a propeller shaft;
a final driven member including a gear that meshes orthogonally with the gear, and an inner diameter engagement part that engages with an outer diameter engagement part of the base cylindrical part of the driven flange that drives the wheel, and a shaft between each engagement part. A sealing material is interposed at the side end of the direction driven flange, and a sealing material is interposed between the holder, which is wrapped from the inner diameter of the driven member to the inner diameter of the driven flange base cylinder, and the inner diameter of the driven flange base cylinder. A sealing device for a wheel drive part of a shaft drive type motorcycle, etc., characterized by: