JPS609115Y2 - Track sealing device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a belly band sealing device that is a seal for preventing muddy water from entering the connecting pin of the belly band link in an endless track such as a bulldozer.

When the endless track is driven, if dirty water containing sand or the like enters between the pins and bushings that connect the links, it becomes an abrasive that wears down the surfaces of the pins and the inner surfaces of the bushes.

If this pin and bush wear causes the pin spacing to become incorrect and the link stretches, it will not mesh properly with the teeth of the starting wheel that starts it, causing abnormal wear of the teeth of the starting wheel, or the impact will cause the entire endless track to mesh. This will significantly shorten the lifespan of the

Conventionally, various sealing devices have been used to prevent the above-mentioned problems, but each of them has the following drawbacks.

Figure 1 shows an outline of an endless track.

Adjacent links 1.2 are connected by bushes 3 and pins 4.

FIG. 2 is a cross-sectional view of the connecting part, and the bushing 3 is fitted into the fitting hole of the inner link 2, the pin 4 is passed through the bushing 3, and its protruding end is fitted into the fitting hole of the outer link 1. Link 1, 2
Concatenate.

A sealing material is placed in an annular recess 5 formed on the inner outer periphery of the fitting hole of the pin 4 in the link 1 to seal it.

2 and 3 show conventional sealing materials. In FIG. 2, a sealing material that combines polyurethane rubber 6a and foamed urethane 6b, which have relatively good sealing properties, is used.
The figure uses a disc spring 7.

The sealing material shown in Figure 2 has good sealing performance, but is soft and deforms when force is applied in the lateral direction of the link, while the disc spring in Figure 3 can receive loads in the lateral direction, but the sealing surface is metal. Sealing performance was poor due to line contact.

Therefore, the present invention aims to eliminate the above-mentioned drawbacks and provide a crawler sealing device which is a seal that can receive lateral force and has good sealing performance, and the part receiving thrust force and the sealing part are made independent. It is characterized by having a structure in which a load is applied to the seal lip part by means of an auxiliary ring.

From this, this belt sealing device can be used for bulldozers with crawlers,
Applicable to tractor excavators, power excavators, etc.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 5 shows a cross section of the seal of the present invention, which includes an annular ring seal 8 made of a wear-resistant and resilient relatively hard material, such as hard urethane rubber, and surrounding the seal 8.
An annular backup ring 9 with a hexagonal cross section made of a relatively soft rubber with wear resistance and elasticity, such as nitrile rubber.
It is composed of a combination of

As shown in FIG. 5, the seal 8 consists of two parts, a heel part 81 and a lip part 82, sandwiching a groove a.
2 is slightly inclined and longer than the heel portion 81 by 11 dimensions, and has an acute angle portion 83 formed at its tip.

Next, to explain its function and effect, FIG. 4 shows a state in which this seal is assembled into the annular recess 5 of the link 1.

Note that 2 is the other link, 3 is the bush, and 4 is the pin.

Since the length of the space formed by the link 1 and the bushing 3 is the same as the length of the heel part 81 of the seal 8, the lip part 82 is deformed outward and the acute angle part 83 of the lip part 82 is attached to the end surface 31 of the bushing. It is pressed by the restoring force of the lip portion 82.

In addition, since the size of the backup ring 9 is 1□ larger than the recess 5, it is compressed when assembled, and has resilience so that it always follows the lateral movement of the bush 3 and always has a lip portion 8.
2 is brought into close contact with the bush end face 31.

In addition, the heel part 81 receives the load in the lateral direction,
The lip portion 82 is prevented from being deformed more than necessary due to excessive force, and is brought into close contact with the bushing end surface 31 with an appropriate pressing force.

As explained above, the lip portion 82 is caused by its own elasticity and the restoring force of the backup ring 9 to
1 with appropriate force, it prevents foreign matter from entering from the outside, and since the heel part 81 can receive lateral loads, it prevents wear of the pin 4 and bushing 3, extending their life. Can be done.

FIG. 6 shows another embodiment of the seal, in which a projection 84 is attached to the heel 81 to make it difficult for the backup ring 9 to come off and to facilitate assembly.

Further, although the backup ring 9 has a hexagonal cross section, a circular cross section can also be used if an appropriate compressive force is obtained.

As described above, according to the present invention, a heel portion and a lip portion that is slightly longer than the heel portion and have an inclined waist are formed by sandwiching a groove between the heel portion and the heel portion, which are made of a relatively hard material that has wear resistance and elasticity. A back-up ring made of an elastic material that surrounds the seal and extends slightly beyond the seal before assembly is combined, and the lip of the seal is inserted into the recess of the link in the bush. By compressing the bushing and the pin so that it is in close contact with the end face and forming the main sealing surface, the bushing and pin are completely sealed and there is no risk of sewage containing sand entering between them, reducing wear. can be prevented.

Therefore, the pin spacing does not go out of order, the wear of the starting wheel is eliminated, and the life of the entire endless track can be extended.

[Brief explanation of the drawing]

Fig. 1 is a partial schematic perspective view of an endless track, Figs. 2 and 3 are sectional views of main parts of a conventional crawler sealing device, and Fig. 4 is a sectional view of main parts showing an embodiment of the crawler sealing device of the present invention. FIG. 5 is a sectional view of the main part of the seal in a state before assembly, and FIG. 6 is a sectional view of the main part showing another example of the seal. 1.2...Link, 3...Butshu,
31... Bush end face, 4... Zen, 5
......Annular recess, 8...Seal, 81.
... Heel part, 82 ... Lip part, 83
...Acute corner, 9...Backup ring.

Claims (1)

[Scope of utility model registration request] an annular seal made of a relatively hard material having wear resistance and elasticity, and formed with a heel portion and a lip portion that is sloped across a groove from the heel portion and is slightly longer than the heel portion; A backup ring made of an elastic material that surrounds the seal and extends slightly from the seal before assembly is combined, and the lip of the seal is in close contact with the end face of the bushing in the recess of the link to form the main seal. A crawler sealing device characterized in that the track sealing device is accommodated in a compressed state so as to form a surface.