Hinge assembly for vehicle tracks and the like

Details Hinge assembly for vehicle tracks and the like Hinge assembly for vehicle tracks and the like

2000-06-28

2002-09-17

Stormer, Russell D. (Department: 3617)

Wheel substitutes for land vehicles

Tracks or treads

Separate transverse connector pin between treads

Reexamination Certificate

active

06450594

ABSTRACT:

FIELD OF THE INVENTION
Our present invention relates to a track assembly for vehicle tracks and, more particularly to tracks for track vehicles such as construction vehicles, earth moving vehicles and special purpose vehicles. The invention also relates to hinge assemblies for track-like chains, for example conveyor chains and chains used for other purposes.
BACKGROUND OF THE INVENTION
Hinge assemblies are provided in vehicle tracks, conveyor chains and the like and can comprise a chain sleeve, a pin extending through this sleeve and having an end projecting beyond the sleeve and two chain bodies which are linked together by the pin and sleeve, including an inner-lying chain member or link which is pressed onto the sleeve and an outer lying chain body or link which is pressed onto the axially projecting end of the pin.
Such chains are widely used in the art and at the hinges of the chain formed between the pin and the bushing, a friction system is provided at which line contact develops between the inner side of the sleeve and the outer side of the pin received therein.
To reduce the friction and thus reduce adhesive wear and minimize the overall wear which can lead to chain lengthening and which can increase the life of the chain or link assemblies, the hinge joints in the past have been fabricated in closed systems with grease or oil containing additives which limit corrosion, increase lubricant life, etc.
Such lubrication systems require seals to prevent leakage of the lubricant from the contact regions between the pin and the sleeve and to prevent entry of foreign particles into the region of contact. For this purpose sealing rings, for example of polyurethane, can be used to seal the oil-filled or grease-filled elements against the exterior. Abrasive wear at the sealing rings can result in failure. A chain utilizing these principles is described for example in DE 31 27 104 C2.
In practice it has been found that such chains, because of the need for grease or oil reservoirs, usually in the form of bores or hollows in the pins, because of the need for a capability of refilling the reservoir and because of the seal arrangement are expensive and difficult or costly to maintain. The use of such tracks for track vehicles operating on sandy soils are especially a problem since the seals are readily damaged by abrasive sand. There is a substantial danger that lubricants which are contaminants for water supplies may leak into the environment.
OBJECTS OF THE INVENTION
It is, therefore, the principal object of the present invention to provide a chain, track for a tracked vehicle or hinge assembly for a tracked vehicle or a conveyor which can be fabricated less expensively than heretofore with a greater useful life, even in abrasive media such as a sandy environment and which also requires significantly less maintenance than has heretofore been the case.
Another object of this invention is to provide an improved hinged assembly for a tracked vehicle or conveyor whereby drawbacks of prior art systems are avoided.
A further object of the invention is to provide an improved method for reducing wear of a hinged assembly for the purposes described and to provide a new use for a wear resistant lacquer composition which is capable of eliminating the need for lubricant reservoirs, seals or the like in hinge assemblies for a tracked vehicle or conveyor.
SUMMARY OF THE INVENTION
These objects are attained, in accordance with the invention by providing the surface of the chain pin, or the inner surface of the chain bushing or sleeve surrounding same, at least in a region in which these surfaces can come into contact with one another during articulation or hinge action, or both of these surfaces, with a wear resistant or antifriction lacquer to form a coating in which the binder or carrier is composed of a synthetic resin on a polyamide-polyimide basis or of a molecular structure comprised of amide-imide monomers and with which molybdenum disulfide (MoS
2
) and/or oxide or hydroxide compounds of molybdenum or mixtures thereof with graphite can be admixed to the polymeric carrier or binder. The molybdenum antifriction composition, including graphite, can be referred to herein as a filler.
More particularly, a hinge assembly for a track vehicle or conveyor can comprise: a sleeve, a pin traversing the sleeve and respective bodies articulated together by the pin and the sleeve and respectively mounted on the pin and the sleeve, the pin extending axially beyond the sleeve and the bodies including an outer body pressed onto an end of the pin projecting beyond the sleeve and an inner body pressed onto the sleeve, the pin having an outer surface juxtaposed with an inner surface of the sleeve and adapted to contact the inner surface at least over portions of the inner and outer surfaces during mutual articulation of the bodies, at least one of the surfaces being coated at least over the portion thereof with a bearing lacquer composed essentially of a polyamide/polyimide synthetic resin carrier or binder or a synthetic resin carrier or binder with a molecular structure containing amide and imide monomers, and an additive contained therein and selected from the group which consists of molybdenum disulfide, oxides and hydroxide compounds of molybdenum, mixtures thereof, and mixtures thereof with graphite.
Preferably the binder or carrier is comprised of a molecular structure with alternating amide-imide monomers.
To improve the adhesion between the antifriction lacquer or bearing lacquer and the surface of the pin and/or bushing or sleeve to which it is applied, the surface to which the lacquer is applied is provided with a primer, preferably in the form of a phosphatization layer, the phosphatization layer being coated in turn with the bearing lacquer.
Alternatively or additionally, the coated surface can be roughed and the bearing lacquer applied to the roughened surface. The surface roughness depth R
a
imported to the bushing or pin can approximate 0.5 &mgr;m. The overall roughness for a drawn tube which can be cut transversely to provide the bushing or sleeve can amount to R
a
of about 1.5 to 2 &mgr;m and the interior of the bushing can retain this roughness to facilitate adhesion of the coating.
Preferably the bearing lacquer contains 15 to 30 volume percent molybdenum disulfide, 3 to 20 volume percent graphite and molybdenum oxides and/or hydroxides as described below. A particularly advantageous bearing lacquer contains 20-25 volume percent molybdenum disulfide and 4-6 volume percent graphite.
The bearing lacquer can be burned onto or baked onto the surfaces of the pin and/or bushing and preferably with a baking temperature of about 200° C. and a duration of about one hour.
The bearing lacquer can be applied in a thickness of about 10-20 &mgr;m and can be a single layer but preferably is comprised of a plurality of layers separately applied and dried or baked with each layer having a thickness of 7 to 10 &mgr;m. In the most advantageous state, the bearing lacquer is comprised of two layers.
According to a feature of the invention the filler or molybdenum solids contained in the bearing lacquer from at least one compound selected from the group which consists of crystalline molybdenum hydroxide monohydrate and molybdenum oxide dihydrate of the formula MoOO
3
.nH
2
O, where n=1 or 2 and compounds of that formula wherein a part of the H
2
O molecules are octahedrally coordinated in layers of {MoOO
4/2
(
0
H
2
)}
n
, and compounds containing ilsemannite Mo
3
O
8
×H
2
O.
Preferably the lacquer contains substoichiometric molybdenum oxide forming Magnéli phases of the formula Mo
n
O
3n−1
where n>4 with the defects appearing in the (102) or (103) crystallographic planes.
The hinge assembly of the invention can operate without lubricants in the form of grease or oil and therefore needs no lubricant reservoir or any facility to refill the reservoir with lubricant. Sealing rings are unnecessary although obviously it is advantageous to avoid the entry of abrasive media into the

Affiliated with

Also associated with

Rating

Hinge assembly for vehicle tracks and the like does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Hinge assembly for vehicle tracks and the like, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hinge assembly for vehicle tracks and the like will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2883943