Wheel substitutes for land vehicles – With means to remove or exclude foreign matter – With end seal between bushing and track link
Reexamination Certificate
1999-06-03
2001-03-27
Stormer, Russell D. (Department: 3617)
Wheel substitutes for land vehicles
With means to remove or exclude foreign matter
With end seal between bushing and track link
C305S118000, C305S202000
Reexamination Certificate
active
06206491
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a crawler device for a crawler vehicle such as a bulldozer and the like, and more particularly, to a crawler device for a crawler vehicle which improves a support member for a lubricating oil seal, an oil groove and the like in a crawler link connection portion.
BACKGROUND ART
A conventional crawler device for a crawler vehicle is provided with right and left crawler links for fastening a multiplicity of crawler plates arranged in a longitudinal direction of a crawler.
The multiplicity of arranged right and left crawler links are overlapped and connected by press fitting a pin and a stationary bush. Then, it has been structured such as to mesh teeth of a drive wheel with an outer diameter portion of the stationary bush so as to rotate, however, since the outer diameter portion of the stationary bush is worn away, a crawler device in which a rotating bush is outwardly fitted to the stationary bush has been developed in recent days.
As a prior art of the crawler device using the rotating bush, there is, for example, Japanese Unexamined PCT Publication No. 6-504747. The contents thereof is structured such that stationary bushes
110
and
110
are respectively press fitted to right and left crawler links
80
a
and
80
b
, as shown in FIG.
9
.
A rotating bush
120
is provided in a center portion between the left stationary bush
110
and the right stationary bush
110
, and the structure is made such as to be separated into three portions.
The center rotating bush
120
meshed with the teeth of the drive wheel (not shown) can rotate around a pin
100
. A portion between an inner cylinder surface of the center rotating bush
120
and an outer diameter portion of the pin
100
are lubricated by an oil, and each of seals
150
and
150
is provided between right and left end surfaces of the rotating bush
120
and each of the stationary bushes
110
and
110
. Each of seals
140
and
140
is provided outside each of the stationary bushes
110
and
110
. Oil grooves
101
and
102
are provided in an inner portion of the pin
100
.
However, in accordance with the technique described in this publication, since each of the seals
150
and
150
is arranged in both end portions of the rotating bush
120
, it is unavoidable to reduce a length or a volume of press fitting between the right and left crawler links
80
a
and
80
b
and each of the stationary bushes
110
and
110
. Further, since the right and left crawler links
80
a
and
80
b
are press fitted and fixed by two stationary bushes
110
and
110
not by single one, there is no bush for combining and connecting between the right crawler link
80
a
and the left crawler link
80
b
, so that a torsional rigidity between the right and left crawler links
80
a
and
80
b
is significantly reduced. Accordingly, there are problems that a holding force due to a press fitting is insufficient against an external force during an operation, a clearance (an end play) of each of seals
140
and
150
at an initial time of assembly is expanded and a sealed lubricating oil is leaked from each of the seals
140
and
150
.
Further, a lubrication between the pin
100
and the rotating bush
120
is insufficient, so that there is a problem that they seize and an endurance life is reduced.
Still further, since the right and left crawler links
80
a
and
80
b
are twisted due to the external force applied during the operation, there is a problem that the pin
100
, each of the stationary bushes
110
and
110
, the rotating bushes
120
and the like are worn away, so that a durability of the crawler device is reduced.
SUMMARY OF THE INVENTION
The present invention is made by paying attention to the conventional problems mentioned above, and an object of the present invention is to provide a crawler device for a crawler vehicle in which a torsional rigidity of a crawler link is secured, a clearance (an end play) of a seal against an external force during an operation maintains an initial value at an assembling time and a lubricating oil sealed in a pin does not leak from the seal.
In accordance with a first invention, there is provided a crawler device for a crawler vehicle comprising a pin and a stationary bush for connecting a right row of crawler link and a left row of crawler link adjacent in a longitudinal direction, and a rotating bush outward fitted to the stationary bush in a freely rotatable manner and meshed with teeth of a drive wheel, wherein the improvement comprises support members respectively inserted to the right and left rows of crawler links, each having an outer diameter portion press fitted to a second connection end portion of each of the crawler links and an inner cylinder portion to which the stationary bush is press fitted and formed in a bracket-shaped cross sectional ring, a first seal inserted between an outer end portion of each of the support members and the opposing crawler links, and a second seal inserted between an inner end portion of each of the support members and both end portions of the opposing rotating bushes.
In accordance with the structure mentioned above, since each of the support members is structured such that the outer diameter portion is press fitted to the second connection end portions of the right and left crawler links and the stationary bush is press fitted to the inner cylinder portion, a torsional rigidity of the right and left rows of crawler links can be secured. Accordingly, a clearance (an end play) of the first and second seals can maintain the initial value at assembling against an external force during an operation. Therefore, the lubricating oil sealed in the pin does not leak from the first and second seals, so that a durability of the seal and a durability of the crawler device are improved.
In accordance with a second invention, there is provided a crawler device for a crawler vehicle as cited in the first invention; wherein the each of support members is a support member formed in a multi-step shaped ring provided with a flange portion brought into contact with an outer peripheral portion of the second seal in an inner end portion thereof.
In accordance with the structure mentioned above, since it is structured such that the flange portion of each of the support members is further brought into contact with the outer peripheral portion of the second seal, a clearance (an end play) of the second seal can securely maintain the initial value at assembling against the external force during the operation. Accordingly, a durability of the seal and a durability of the crawler device can be improved.
In accordance with a third invention, there is provided a crawler device for a crawler vehicle as cited in the first invention or the second invention, wherein each of the support member is structured such that an outer end portion thereof is attached between the right and left rows of crawler links and the stationary bush and an inner end portion is attached between the crawler links and the rotating bushes.
In accordance with the structure mentioned above, since the outer end portion and the inner end portion of each of the support members are attached between the crawler links, the stationary bush and the rotating bush, each of the support members can not slip away against the external force during the operation. Accordingly, the torsional rigidity of the right and left crawler links
8
and
9
can be sufficiently secured and a clearance (an end play) of the seal can maintain an initial value at assembling in a more secure manner. Therefore, a durability of the crawler device is improved and the lubricating oil sealed in the pin does not leak from the seal.
In accordance with a fourth invention, there is provided a crawler device for a crawler vehicle as cited in the first invention, wherein the right and left end portions of the pin which overlaps and press fits the first connection end portion and the second connection end portion of the right and left rows of crawler links are structured such that each of stop rings for pre
Komatsu Ltd.
Sidley & Austin
Stormer Russell D.
LandOfFree
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