JPS6131216Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a planetary gear type final reduction gear mounted on a crawler type vehicle.

Conventionally, as this type of final reduction gear, those shown in FIGS. 1 and 2 are known.

However, in the structure shown in Fig. 1, the planetary gear mechanism A
Since the sprocket b is connected to the carrier a by spline fitting, in order to replace the sun gear c, the crawler track d must be divided and the sprocket b must be removed, making the operation cumbersome.

Furthermore, with the structure shown in Fig. 2, the sun gear c can be replaced by removing the cover e without dividing the crawler track d or removing the sprocket b. Since the input side gear chamber g and the planetary gear mechanism side chamber h are separated, and there are two lubricating oil reservoirs i and j, it is necessary to drain the oil from each of the two chambers when changing the oil. The work becomes troublesome, and when draining the oil from the side chamber h of the planetary gear mechanism on the outside of the car body, the chamber h rotates together with the sprocket b, so it is necessary to rotate it so that the drain plug position is directly below. However, the final reduction mechanism is installed on the left and right sides of the car body, and the drain positions are usually not in the same position on the left and right sides, so it is necessary to turn the car a little (that is, rotate only one sprocket b) to align the left and right drain positions. .

For this reason, it is not possible to turn in a narrow space, so in this case, after draining and refilling the oil in the chamber h on one side, drive the vehicle for a short distance to drain and refill the oil in the chamber h on the other side. It is very troublesome to have to do this.

This invention was devised in view of the above circumstances, and its purpose is to create a planetary model that allows the sun gear to be replaced without dividing the track or removing the sprocket, and also has a single lubricating oil reservoir to facilitate oil replacement. An object of the present invention is to provide a gear type final reduction gear.

An embodiment of the present invention will be described below with reference to FIG.

The final reduction gear case 1 has a shape in which an outer case 4 is fixed with bolts 5 to an inner case 3 that is bolted to the vehicle body 2 side.
Second holes 6 and 7 are formed above and below, and the first
A hole 7' is formed in the vehicle body 2 concentrically with the hole 6, and an output shaft 8 of an HST (not shown) is rotatably fitted into the hole 7' via a bearing 9, and a spline portion 8a of the output shaft 8 is inserted. One end side of the torque tube 10 is spline-fitted to the torque tube 10 .

One end of a pinion shaft 11 is fitted into the other end of the torque tube 10.
1 is rotatably supported via a bearing 14 on a support plate 13 fixed to the outer end wall 3b of the inner case with bolts 12, and has a pinion tooth portion 11a.
A large diameter gear 15 is meshed with the .

The large diameter gear 15 is rotatably supported in the second hole 7 via a bearing 16, and the spline hole 1
A sun gear 18 is spline-fitted and connected to 7, and a carrier 19 is rotatably supported on the outer peripheral surface 15a of the boss via a bearing 20. Bearing 23
A ring gear 24 that meshes with the planetary gear 21 is provided to mesh with a ring gear 25 provided on the outer case 4.

A sprocket 27 is rotatably provided on the boss portion 4a of the outer case 4 via a bearing 26 on the outer side of the vehicle body than the carrier 19, and an output shaft 29 fixed to the sprocket 27 with bolts 28 is attached to the inner peripheral wall of the boss portion 5a. Spline hole 19 of the carrier 19
A is connected by spline fitting. In addition, the sprocket 27 is connected to the hub 27a and the pigment teeth 2.
7b is bolted together, and
The drag gear 27b meshes with the crawler belt B.

As such, the rotation of the output shaft 8 is transmitted to the sprocket 27 via the pinion tooth portion 11a, the large diameter gear 15, the sun gear shaft 18, the planetary gear 21, the carrier 19, and the output shaft 29 to drive the crawler belt B. do.
That is, the power is transmitted to the sprocket 27 via the planetary gear type final reduction mechanism.

A drive brake A is provided between the torque tube 10 and the inner case 3.

In other words, the drum 3 is located in the first hole 6 of the inner case 3.
0 is fitted onto the inner end surface 30a of the drum 30, and an annular receiver 31 is fastened and fixed to the inner case 3 together with the drum 30 with long bolts 32.
Brake discs 36 and 37 are alternately spline-fitted into the spline portion 31 of the receiver 31 and the spline portion 10a of the torque tube 10, and one end of the pinion shaft 11 is inserted into the hole 30b through a bearing 33. Further, an annular recess 34 is formed in the drum 30, and a piston 35 is spline-fitted into the annular recess 34 to form an annular pressure receiving chamber 38. A spring 39 urges the brake discs 36, 37 in a direction to press them against the receiving body 31.

The pressure receiving chamber 38 communicates with a brake operating valve (not shown) through an oil hole 40'.

When the pressure receiving chamber 38 is communicated with the drain, the piston 35 is pushed by the spring 39 and the brake discs 36, 37 are pressed against the receiving body 31, so that the torque tube 10 can be fixed and the sprocket 27 can be braked.

Further, when pressure oil is supplied to the pressure receiving chamber 38, the piston 35 is moved against the spring 39, so the brake discs 36, 37 and the receiving body 31 are separated and the parking brake is released.

Therefore, the sun gear 18 can be replaced in the following manner.

First, loosen the bolt 28 and pull out the output shaft 29 from the boss portion 4a.
Screw together the threaded part of the longer material to form the spline hole 17.
It would be better to extract more. In addition, when installing it, it is sufficient to perform the operation opposite to that described above.

Therefore, the sun gear 18 can be replaced without dividing the track B or removing the sprocket 27.

In addition, since the large diameter gear 15 on the input side and the planetary gear type reduction mechanism are housed in one gear chamber c formed on the vehicle body side from the inner case 3, outer case 4, and sprocket 27, there is no lubricating oil reservoir. Since there is only one lubricating oil c′, when replacing the lubricating oil, only one lubricating oil c′ needs to be drained, making the oil change process easier, and since the lubricating oil reservoir c′ does not rotate, the drain plug is always directly below. This eliminates the need to turn or drive the vehicle, making oil changes even easier.

Note that three planetary gears 21 are meshed with the sun gear 18, and the number of teeth of the planetary gear 21 is about twice that of the sun gear 18, so the life of the sun gear 18 is about 1/6 of that of the planetary gear 21. Because the sun gear 18 becomes short due to early wear and tear, the sun gear 18
It is of practical importance to replace the

The present invention is as described above, and the crawler track is divided,
The sun gear 18 can be replaced without removing the sprocket 27, and only one lubricating oil reservoir c' needs to be formed within the final reduction gear case 1, making the oil change operation easier.

[Brief explanation of drawings]

1 and 2 are sectional views of a conventional example, and FIG. 3 is a sectional view showing an embodiment of the present invention. 1 is the final reduction gear case, 2 is the vehicle body, 8 is the output shaft,
15 is a large gear, 17 is a spline hole, 18 is a sun gear, 19 is a carrier, 21 is a planetary gear, 24 is a ring gear, 27 is a sprocket, and 29 is an output shaft.

Claims (1)

[Scope of utility model registration request] A large gear 15 is rotatably provided in the final reduction gear case 1 attached to the vehicle body 2, and the large gear 15 is attached to the vehicle body 2.
A planetary gear 21 is connected to the output shaft 8 on the side, and a sun gear 18 is spline-fitted into the spline hole 17 of the large gear 15, and meshed with the sun gear 18.
A carrier 19 equipped with a carrier 19 is rotatably supported in the final reducer case 1, and a ring gear 24 meshed with the planetary gear 21 is fixedly provided in the final reducer case 1. The sprocket 27 is rotatably supported on the boss portion, and
An output shaft 29 removably connected to the sprocket 27 is inserted into the boss portion, removably connected to the carrier 19, and opposed to the sun gear 18;
Furthermore, the planetary gear type final reduction gear is characterized in that a locking portion is formed on the sun gear 18 so that the sun gear 18 can be freely pulled out from the boss portion.