JPS6221460Y2 - - Google Patents

Description

[Detailed Description of the Invention] The purpose of the present invention is to simplify the structure of a rear wheel drive device for a vehicle such as a tractor to facilitate disassembly and assembly, and to increase the strength of the rear axle box. It is.

In vehicles such as tractors, brakes are installed on both sides of the transmission case to brake the differential yoke shaft.
Some vehicles are designed to interlock the differential yoke shaft and the rear axle via a final reduction gear laterally outward of the brake. In this type of case, the brake and the final reduction gear are usually separated by a large distance in the lateral direction, which makes the differential yoke shaft extremely long and also makes it impossible to integrate the brake case, rear axle box, final reduction case, etc. First, they had the disadvantage that they had to be made separately, resulting in a complicated structure and complicated assembly and disassembly. The number of parts also increases.

The present invention is designed to solve these conventional problems, and its feature is that a brake case 15 having a peripheral wall 15a and a side wall 15b is mounted on both sides of the transmission case 1. The differential yoke shaft 1 is installed inside this brake case 15.
0, and a rear axle 23 interlocked with a differential yoke shaft 10 via a final reduction gear 20 outside a brake case 15 is provided at a different level from the differential yoke shaft 10. , the final reduction gear 20 is connected to the brake case 15.
Brake case 1
5, a support wall 19 is integrally formed with the side wall 15b so as to cover the final reduction gear 20 from inside, and a bearing 27 is provided on the inner end side of the rear axle 23 at a portion of the support wall 19 corresponding to the peripheral wall 15a. The rear axle box 25, which is inserted and supported through the rear axle box 25 and supports the intermediate portion of the rear axle 23, is attached to the brake case 15 and the support wall 19 so as to cover the final reduction gear 20 from the outside.

The present invention will now be described in detail with reference to the illustrated embodiment. FIGS. 1 and 2 illustrate a rear wheel drive system for a tractor. In the figure, reference numeral 1 denotes a transmission case, which constitutes a tractor body 2. As shown in FIG. 3 is a differential device built into the rear part of the transmission case 1, and the differential case 4 is rotatably supported by the transmission case 1 through a pair of left and right ball bearings 5 and a bearing case 6 about a horizontal axis. . Bearing case 6
comprises a mounting flange part 7 located on the outside of the mission case 1, and a brake receiving part 8 formed concentrically so as to protrude outward in the longitudinal direction and outward in the lateral direction of the flange part 7. Bolt 9 at flange part 7
It is attached to the transmission case 1 by.
The differential device 3 has a pair of left and right differential yoke shafts 10, and each of the differential yoke shafts 10 penetrates the inside of the bearing case 6 and projects to the outside of the transmission case 1. Reference numeral 11 denotes a brake for braking the differential yoke shaft 10, and a brake disc 12 spline-coupled to the differential yoke shaft 10 and provided facing the braking surface 8a of the brake receiver 8, which presses the brake disc 12 toward the braking surface 8a. A brake case 15 is provided with a brake piston 13, a friction plate 14 interposed between the two, and the like, and is attached to the transmission case 1 with bolts 16 so as to cover these from the outside. The brake piston 13 is ring-shaped and is slidably fitted into a cylinder chamber 17 integrally formed with the brake case 15. The brake case 15 has a peripheral wall 15a and a side wall 15b.
A ball bearing 18 for supporting the differential yoke shaft 10 is fitted in the brake disc 12 near the outside thereof, and a step-shaped support wall 19 is integrally formed facing diagonally downward at the rear. 20 is the support wall 19
The final reduction gear is disposed near the brake 11 with the differential yoke shaft 10 in between. The large-diameter gear 22 is spline-fitted to the rear axle 23. The rear axle 23 is supported by a rear axle box 25 via a ball bearing 24 at a substantially central portion in the lateral direction, and a small diameter shaft portion 26 at the inner end corresponds to the peripheral wall 15a of the support wall 19 via a ball bearing 27. partially supported. The large diameter gear 22 is axially fastened together with the inner ring of the ball bearing 24, the collar 29, etc. between a stepped portion 23a formed on the rear axle 23 and a nut 28. The rear axle box 25 is press-formed from a sheet metal material, and is attached to the support wall 19 with bolts 30 at the peripheral edge so as to cover the final reduction gear 24 from the outside in the lateral direction. 25 becomes gradually thinner as it moves outward in the lateral direction, and a bearing case 31 is integrally welded to its outer end. The bearing case 31 is made by cutting a steel pipe or the like, and the ball bearing 24 is fixed thereto by a pair of retaining rings, and an oil seal 32 is fitted on the outer side thereof. 33 is a rear wheel, which has a wheel disc 34;
4 is a bolt 3 attached to the flange portion 35 at the outer end of the rear axle 23.
It is attached by 6. Note that 37 is a towing hitch provided at the rear end of the tractor body 2, and 38 is a check chain connecting pin provided on the support wall 19.

In the above configuration, at the time of assembly, the differential device 3 is first assembled into the transmission case 1 via the ball bearing 5 and the bearing case 6. On the other hand, the differential yoke shaft 10 is connected to the brake case 15 via a ball bearing 18.
is rotatably inserted and supported, the piston 13 is fitted into the cylinder chamber 17, and the friction plate 1
4 and the brake disc 12, the inner end of the differential yoke shaft 10 is fitted into the differential side gear of the differential device 3 from the outside through the inside of the bearing case 6, and the brake case 15 is inserted into the transmission case 1. Fasten with bolts 16 according to the mounting surface.
At this time, the brake disc 12 faces the braking surface 8a formed integrally with the bearing case 7. Next, the rear axle 23 is inserted and supported in the rear axle box 25 via the ball bearing 24, and the collar 29 is attached to the rear axle 23 from the inner end side.
Then, fit the large diameter gear 22 and tighten the nut 28. Then, the small-diameter shaft portion 26 at the inner end of the rear axle 23 is supported by the support wall 19 via a ball bearing 27, and the outer peripheral edge of the final reduction gear 20 is covered with the rear axle box 25 from the outside with bolts. 30 to the support wall 19, and finally the rear wheel 33 is attached to the flange portion 35 of the rear axle 23.

Note that the rear axle box 25 may be made of aluminum die-casting or the like.

In the present invention, since the brake case is integrally formed with the support wall that covers the final reduction gear from the inside, the number of parts is small and the structure is simple. Furthermore, since the final reduction gear is located close to the brake, the lateral dimensions of the brake case and the support wall can be reduced and the weight can be reduced. Support the inner end of the rear axle with a support wall,
In addition, since the intermediate portion is supported by the rear axle box, the burden on the rear axle box can be reduced. Moreover, the inner end of the rear axle is connected to the support wall through a bearing in the part corresponding to the peripheral wall of the brake case, so even though the inner end of the rear axle is supported by the support wall, the bearing part is It can be reinforced with a surrounding wall, significantly increasing its strength. Since the rear axle box is attached to the support wall so as to cover the final reduction gear, this part is easy to assemble and disassemble. Further, since the base side of the rear axle box has a large diameter, the above-mentioned load is reduced and its strength is significantly increased.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a sectional view and FIG. 2 is a view taken along the - arrow in FIG. 1. 1...Mission case, 3...Differential device, 1
0...Differential yoke shaft, 11...Brake, 15...
... Brake case, 19 ... Support wall, 20 ... Final reduction gear, 23 ... Rear axle, 25 ... Rear axle box,
33...Rear wheel.

Claims (1)

[Scope of utility model registration request] A brake case 15 having a circumferential wall 15a and a side wall 15b is mounted on both sides of the transmission case 1, and a differential yoke shaft 1 is mounted inside the brake case 15.
0, and a rear axle 23 interlocked with a differential yoke shaft 10 via a final reduction gear 20 outside a brake case 15 is provided at a different level from the differential yoke shaft 10. , the final reduction gear 20 is connected to the brake case 15.
Brake case 1
5, a support wall 19 is integrally formed with the side wall 15b so as to cover the final reduction gear 20 from inside, and a bearing 27 is provided on the inner end side of the rear axle 23 at a portion of the support wall 19 corresponding to the peripheral wall 15a. A rear axle box 25 for supporting an intermediate portion of a rear axle 23 is attached to a brake case 15 and a support wall 19 so as to cover a final reduction gear 20 from the outside. Wheel drive.