JPH02142976A - Dust seal for caterpillar tread joint connecting pins - Google Patents

Abstract

PURPOSE:To maintain a seal effect on a sealing surface and a closed part by installing a sealing part, partitioning a dust seal storage recess inside and outside and having elastic force in both circumferential and axial directions in a gap with a hermetically sealed part engaging an opposed sealing surface and solidly sealing and pressing under pressure. CONSTITUTION:Hermetically sealed parts 1, 2 and a seal part 5 are unified as one body via a hermetical seal supporting metal ring holding parts 3, 4 and the seal part 5 has resilient elastic force in the axial direction, giving axial seal pressure to the sealed parts 1, 2, and also has elastic restoring force against a twist in the circumferential direction. Next, the holding members 3, 4 is provided with two projection pins 8, 9, fitting them in pin receiving holes 19, 20, and then these members 3, 4 are unified in a bush 14 and a crawler plate 11 as one body. Accordingly, the sealed parts 1, 2 maintain a seal effect without coming into slidingly contact with opposed sealing surfaces 6, 7 owing to rotation of the unified holding members 3, 4 even if rocking rotation of the bush 14 and the crawler plate 11 occurs. In addition, the seal part 5 functions as elastic restoration against each twist of these holding members 3, 4, thus it has a function as both inside and outside partitions of a dust seal storage recess 15.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a dust seal for a track joint connecting pin in a track type construction vehicle.

(Prior Art) As shown in FIG. 3, the dust seal of the joint connecting pin portion of the crawler track is formed by forming a recessed step portion 38 inside the pin boss portion 33 of the track joint 32 press-fitted into the connecting pin 31. The seal lip portion 35 of the dust sill 34 is pressed into contact with the lip surface 39 of the end face of the bushing 37 that is press-fitted into the pair of shoe shoe joints 36 to prevent wear that enters from the gap 40 between the shoe shoe joints 32 and 36. The purpose is to seal off foreign matter and seal off the leakage 41 of lubricating oil between the pin 31 and the bush 37. (Although only one side has been described above, the dust seals are arranged on both sides.) One of the track joints 36 to be articulated there is fitted and fixed to a bush 37 and rotates at a constant angle around the connecting pin 31. However, the other adjacent track joint 32 is fitted and fixed to the connecting pin 31 and rotates at a certain angle in the inner recess of the bush 37.

The rotational movement between the two is performed relative to each other, and the purpose is to insert and secure the dust seal 34 into the inner recess of one track joint 32 and to attach the seal lip 35 to the end surface of the bush 37 integral with the other track joint 36. By adopting a configuration that presses against the lip surface 3,
Adjacent track joints 32 that rotate in relative directions due to the sliding action of 9.
．． This seals the space between 36 and 36.

(Problem to be Solved by the Invention) However, in a sealing means in which the seal lip portion 35 and the seal surface 39 slide against each other, the seal lip portion and the seal surface will wear out and the sealing function will deteriorate, and the connection Since there is fitting play in the radial direction between the pin 31 and the bushing 37, a radial displacement movement occurs between the adjacent track joints 32 and 36, and the seal lip portion 35 slides eccentrically within the plane.

For this reason, there is a problem in that fine abrasion particles adhering to the sealing surface 39 get caught in the seal lip portion 35 and accelerate the abrasion of the lip surface 39.

In view of this, the present invention eliminates the relative directional sliding action between the sealing surface of the shoe joint and the bushing and the sealing portion of the dust seal that contacts the sealing surface, thereby ensuring a reliable sealing effect that does not cause wear of the sealing surface or the sealing portion. The purpose of this invention is to provide a dust seal for connecting crawler joints, which provides a dust seal for connecting track joints, thereby overcoming the drawbacks of the prior art.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a dust seal installed between the opposing seal surfaces formed by the dust seal accommodating recess of the outer track joint and the bush end face of the inner track joint. , a first hermetic seal part that engages with the opposing seal surface to form an integral sealing pressure contact; and a first hermetic seal part that is interposed between the first hermetic seal part and partitions the dust seal accommodation recess into the inside and outside, and is formed at a constant angle in the circumferential direction. It is characterized by a configuration including a second seal portion having a degree of free rotational elasticity and having an elastic force in the axial direction.

(Function) With the above configuration, the first annular seal is given compressive sealing pressure in the axial direction by the second seal part to prevent abrasion particles from entering from the seal surface, and the second seal part The space between the seals is shielded to separate the inside and outside, preventing abrasion particles from entering from the outside.

The metal annular holding member for supporting the seal cooperates with the relative rotational movement of the sealing surface at a certain angle, and holds the first
Prevent sliding action from being applied to the annular seal.

Furthermore, the relative rotational movement of the metal annular holding member for supporting the seal at a certain angle applies a torsional movement to the second seal portion.
This torsional movement takes place within the elastic variation of the second sealing part and does not affect the sealing action.

(Example) Hereinafter, the present invention will be explained with reference to an example shown in FIG. 1. A dust seal for a track joint connecting pin according to the present invention is shown in a partially sectional front view with one side omitted in FIG. As shown, a track joint 11 (only one side shown) is fixed to the track board 10,
The track shoe joint 12 (only one side is shown) is fixed to an adjacent track shoe (not shown), and the ends of the adjacent track shoe joints 11 and 12 are overlapped. (Although only the right side is shown in the figure, there is a similar combination of adjacent shoe joints on the left side (not shown).) There is a connecting pin 13 at the joint of the shoe shoe joints 11 and 12. The joint 11 and the connecting pin 13 are tightly fitted together. The bush 14 is fitted into the connecting pin 13 with a clearance, and the inner track joint 12 is firmly connected to the end of the bush 14. Therefore, the track joint 11 swings and rotates due to the integral connecting pin 13, and the track joint 12 is moved by the integral bush 1.
4 causes a rocking rotational movement. A dust seal housing recess 15 is formed inside the JII plate joint 11, and the dust seal housing recess 15 is formed inside the JII plate joint 11.
It has an end surface 16 of 4 and an opposing surface 17.

The annular stopper 18 is provided to keep the axial width of the dust seal accommodation recess 15 constant and to restrict the axial movement of the track joints 11 and 12.

The above configuration is conventionally known, and is characterized in that the dust seal D is installed in the dust seal accommodation recess 15 as in this embodiment.

Opposing seal surfaces 6.7 are installed on the dust seal D between the end surface 16 of the bushing 14 and the opposing surface 17 of the dust seal accommodation recess, respectively, and the opposing seal surfaces 6, 7 are crossed by the connecting pin 13. , the dust seal D has an annular configuration.

Further, the dust seal D includes first sealing portions 1 and 2 of an annular plane in contact with the opposing sealing surface 6.7, and a second sealing portion 5 of a partition annular wall that partitions the dust seal accommodation recess 15 from inside to outside.
has.

The first seal part 1.2 and the second seal part 5 are integrally constructed with a metal annular holding member 3.4 for supporting the seal, and the second seal part 5 has an axial repulsive force. It applies sealing pressure in the axial direction to the first hermetic seal portion 1.2 and has an elastic restoring force against torsion in the circumferential direction.

The metal annular holding member 3.4 for supporting the hermetic seal is provided with a plurality of protruding pins 8.9 passing through the first hermetic seal portions 1, 2 in the annular circumferential direction.

This protruding pin 8.9 has a pin receiver bored in the end surface 16 of the bushing 14 and the facing surface 17 on the side of the dust seal accommodation recess 15 of the track joint 11. The annular holding member 3°4 is integrally engaged with the bushing 14 and the track joint 11. As a result, the first sealing portion 1.2, which is pressed and sealed against the sealing surface 6.7 by the repulsive elastic pressure of the second sealing portion 5, connects the bushing 14 and the track joint 11.
Even if a relative joint rocking rotation occurs, the same rotation of the integrally engaged metal annular holding member 3.4 for supporting the seal prevents the sliding action from occurring with the opposing seal surface 6.7, resulting in a seal. The sealing effect will not deteriorate due to wear of the parts.

The second seal portion 5 has an elastic restoring action against the torsion of the relative rocking rotation of the metal annular holding member 3.4 for supporting the seal, and has a sufficient function as an inner and outer partition wall of the dust seal accommodation recess 15. It turns out.

FIG. 2 shows another embodiment of the present invention, in which the configuration of the second seal portion 5 is such that a pair of annular structural springs 21 and 22 are combined to apply sealing pressure in the axial direction. When the metal annular holding member 3.4 for supporting the seal rotates in a relative direction, it is absorbed by the sliding action of the combined surfaces of the pair of annular structural springs 21 and 22, and the first hermetic seal portion 1
, 2, there is a dust seal accommodation recess 1 between the metal annular holding members 3 and 4 for supporting the seal.
A partitioning elastic wall 23 is provided to partition 5 into inside and outside.

The other configurations are the same as those of the present embodiment. In the case of this embodiment, the second seal portion 5 is divided into a means for applying axial sealing pressure and an elastic wall means for partitioning the inside and outside of the dust seal accommodation recess 15. Therefore, the elastic wall 23 is provided with a strong No elastic reaction force is required, so even if torsional action is applied during rocking rotation in relative directions, it can flexibly respond, reduce elastic fatigue failure, and maintain a long life.

(Effects of the Invention) Since the present invention is constructed as described above, the sealing portion does not come into sliding contact with the sealing surface, so that a high sealing effect can be obtained without any problems caused by wear. Furthermore, even if radial movement of the sealing surface occurs, the sealing surface and the sealing part are integral, but there is no displacement effect of the sealing part.
Therefore, excellent effects such as no entrapment of wear particles and no damage to the hermetically sealed portion are achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of a dust seal of a track joint connecting pin according to the present invention, FIG. 2 is a sectional view of another embodiment of the present invention, and FIG. 3 is a sectional view of a conventional crawler joint connecting pin. FIG. 3 is a cross-sectional view of the dust seal. l, 2... First sealing part, 3.4... Metal annular holding member for supporting the sealing seal, 5... Second sealing part,
6.7...Opposing seal surface, 8.9...Protruding pin, 1
0... Shoe shoe, 11.12... Shoe shoe joint, 13...
Joint connecting pin, 14--button, 15--dust seal accommodation recess, 16--end surface, 17--opposed surface,
18... Annular stopper, 19.20... Hole for pin receiver, 21.22... Annular structural spring, 23... Inner/outside partition elastic wall, D... Dust seal. Applicant: Komatsu Ltd. Figure 3

Claims (1)

[Claims] 1) In a dust seal installed between the opposing seal surface formed by the dust seal accommodation recess of the outer track joint and the bushing end surface of the inner track joint, the dust seal engages with the opposing seal surface. A first hermetic seal part is interposed between the first hermetic seal part and integrally press-fitted with the first hermetic seal part to partition the dust seal housing recess into the inside and outside, and has a degree of rotational freedom elasticity at a constant angle in the circumferential direction, and an axially A dust seal for a crawler joint connecting pin, comprising a second seal portion having an elastic force in a direction. 2) The dust seal for a crawler joint connecting pin according to claim 1, wherein the first sealing portion comprises a sealing portion and a metal annular holding member that is integrally engaged with the sealing surface. 3) The second seal portion is comprised of an axial resilient means that combines a pair of annular disc spring members, and an elastic wall membrane means that partitions the dust seal accommodation recess into the inside and outside. The dust seal for the crawler joint connecting pin described in 1.