Wheel substitutes for land vehicles – With frame carried endless track – With roller antifriction means
Patent
1992-09-14
1998-12-29
Stormer, Russell D.
Wheel substitutes for land vehicles
With frame carried endless track
With roller antifriction means
305195, 305202, B62D 5518
Patent
active
058532331
DESCRIPTION:
BRIEF SUMMARY
THIS INVENTION is concerned with improvements in or relating to crawler track assemblies.
More particularly the invention is concerned with an improved bush for connection of crawler track chain links and a crawler track system employing such links.
The most commonly used bush for joining crawler track links comprises a cylindrical pin with an annular sleeve rotatably mounted thereon in a plain bearing relationship. In assembling a crawler track chain, the sleeve is press fitted into aligned apertures in opposing sides of one end of a chain link. An adjacent link is then connected by passing the central pin through the sleeve and press fitting the pin in aligned apertures in the spaced jaws of the adjacent link.
Accordingly while the pin and sleeve are relatively rotatable to some degree as adjoining links are flexed, the pin and sleeve are not rotatable relative to respective links in which they are press fitted.
Such prior art chain bushes are particularly susceptible to wear. As a crawler tractor moves across a ground surface the tension in the track is borne by the pin and sleeve. Constant tension combined with relative rotation as the links flex while moving around the drive sprocket and idler gives rise to substantial wear on the outer surface of the pin and the inner surface of the sleeve.
In addition, the outer surface of the sleeve is subjected to substantial wear from the drive sprocket teeth due to the combined effects of tension and the fact that the surface of the sleeve grinds against the sprocket teeth as the chain links flex around the sprocket. Generally speaking it is preferred that the bushes wear preferentially over the sprocket as it is less expensive to replace chain bushes than drive sprockets.
Rebushing of crawler track chains is a function often carried out in the field and this task is extremely expensive and time consuming. Apart from the actual cost to an operator of the re-bushing of a crawler track chain system, a loss in earning capacity results from having the crawler tracked vehicle out of operation for two or three days while the-track maintenance procedure is being carried out.
In order to alleviate the problems of crawler track maintenance due to worn chain bushes, it has been proposed to use a bush comprising a central pin and a sleeve rotatably journalled on the pin by a roller bearing assembly. Although such bushes show a reduction in internal wear between the pin and sleeve, there still exists the problem of wear between the bushes and the drive sprocket.
It is an aim of the present invention to overcome or alleviate the problems associated with prior art crawler track chain bushes and to provide an improved crawler track assembly.
According to one aspect of the invention there is provided a bush assembly for a crawler track chain mechanism, said bush assembly comprising a cylindrical pin having rotatably journalled thereon a first sleeve member and a second sleeve member rotatably journalled on said first sleeve member, said cylindrical pin and said first sleeve member each being adapted for frictional engagement in respective ends of a crawler track chain link.
Suitably said first sleeve member is rotatably journalled on said cylindrical pin by a first bearing means.
Suitably said second sleeve member is rotatably journalled on said first sleeve member by a second bearing means.
The first and second bearing means may comprise plain bearing surfaces or roller bearings such as needle roller bearings or a combination thereof.
Preferably said second sleeve member is rotatable in use between opposed yoke arms of a crawler track chain link.
According to another aspect of the invention there is provided a crawler track mechanism for vehicles, said mechanism comprising a track including track plates mounted on crawler track chain links, said chain links being pivotally interconnected by bushes according to a first aspect of the invention, and, a drive sprocket adapted to receivably locate in recesses between adjacent sprocket teeth rotatable outer sleeves associated with r
REFERENCES:
patent: 1319120 (1919-10-01), Schutz
patent: 2838345 (1958-06-01), Miller
patent: 3032376 (1962-05-01), Blazek et al.
patent: 3492054 (1970-01-01), Boggs et al.
patent: 3547502 (1970-12-01), Howard
patent: 3567294 (1971-03-01), Simpson et al.
patent: 3731551 (1973-05-01), Nelson
patent: 4050750 (1977-09-01), Yoshihashi et al.
patent: 4149758 (1979-04-01), Livesay
patent: 4191431 (1980-03-01), Roley et al.
patent: 4199202 (1980-04-01), Maeda
patent: 4222616 (1980-09-01), Brewer
patent: 4636014 (1987-01-01), Dennison et al.
patent: 5069509 (1991-12-01), Johnson et al.
patent: 5069510 (1991-12-01), Cory
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