ZA200103664B

ZA200103664B - Method of repairing a worn track link.

Info

Publication number: ZA200103664B
Application number: ZA200103664A
Authority: ZA
Inventors: Marthinus Jacobus Van Rooyen
Original assignee: Marthinus Jacobus Van Rooyen
Priority date: 1998-11-16
Filing date: 1999-11-15
Publication date: 2002-08-23

Description

«a WO 0029276 PCT/BY9/01829 .

METHOD OF REPAIRING A WORN TRACK LINK

INTRODUCTION AND BACKGROUND TO THE INVENTION

This invention relates to a track link for an endless link assembly. This invention further relates to a method of repairing a worn track link for an endless link assembly.

A portion of an endless link assembly according to the prior art is generally designated by reference numeral 2 in the enclosed figure 1. The endless link assembly 2 comprises a plurality of track links 10 (shown in more detail in figure 2) which are connected to each other by pivots 4. The link assembly 2 is used

TA with a vehicle of which a lower rear portion is generally designated by reference numeral 6 in figure 1. The vehicle 6 is provided with idlers 8a and rollers 8b, which are supported on a bearing surface 26, provided by each track link 10.

The track links 10 are relatively expensive and a disadvantage of the known track links 10 is that the bearing surfaces 26 are prone to wear. The track links 10 therefore have to be replaced regularly, and the worn track links 10 are usually discarded.

It is known to build up the worn bearing surface of a track link by depositing metal on the surface by welding. See for example CATERPILLAR CUSTOM

TRACK SERVICE HANDBOOK, 14™ edition 1998 page 26 to 27. One of the disadvantages of such method is that only track links meeting particular criteria, as set out in the above handbook, can be rebuild.

Another disadvantage of such a method is that the track link has to be machined after the surface has been built up. Yet another disadvantage of this method is that only about 80% of the original life of the track link can be added by building the track link up using such method.

Even another disadvantage of said method is that due to heat build up in the track link during welding, the track link tends to distort and crack. As a result, this method is hardly ever used and as a rule, worn track links are therefore still yy being discarded notwithstanding the fact that the above described method is prescribed in said handbook. Such worn track links further present a pollution problem as it is difficult to recycle due to lubricants that are captured in the pins and bushes of the track links.

OBJECT OF THE INVENTION

It is accordingly an object of the present invention to provide a frack link, an endless link assembly, and a method of repairing a worn track link, with which the aforesaid disadvantages may be overcome or at least minimised.

= TPW0 0029276 PCT/IBI9NIBLY : 3 i

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a method of repairing a worn track link of the type having a bearing surface, the method including the steps of providing a solid bearing element having a bearing surface; and securing the bearing element to the track link to cover the bearing surface of the track link.

The step of securing the bearing element to the track link may include the step of welding the bearing element to the track link.

The method may include the further step of providing an interface between the

NA track link and the bearing element prior to the step of welding. :

According to a second aspect of the invention there is provided a track link comprising a body having a bearing surface; and a solid bearing element also having a bearing surface, the bearing element being secured to the body to cover the bearing surface of the body.

The bearing surface of the bearing element may be complementary to the bearing surface of the body.

The bearing element may be welded to the body.

4 | .

The bearing element may define an interface along which it may be welded to the track link.

The interface may comprise a peripheral groove formation.

The interface may further comprise a centrally disposed hole extending through the bearing element.

Preferably the bearing element is of a material which is relatively more resistant to wear than the body. *N

According to a third aspect of the invention there is provided an endless link assembly comprising at least one track link having a bearing surface; and a bearing element also having a bearing surface, the bearing element being secured to the track link to cover the bearing surface of the track link.

The bearing surface of the bearing element may be complementary to the bearing surface of the track link.

The bearing element may be welded to the track link.

}

The interface may comprise a peripheral groove formation. 5 ~The interface may further comprise a centrally disposed hole extending through the bearing element.

Preferably the bearing element is of a material which is relatively more resistant to wear than the track link.

E According to a fourth aspect of the invention there is provided a bearing element for repairing a track link of the type comprising a body having a bearing surface, the bearing element comprising a solid member having a bearing surface which is complementary to the bearing surface of the track link; and an interface along which it is connectable to the track link to cover the bearing surface of the track link.

The interface may comprise a peripheral groove formation.

Co

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described further, by way of example only, with reference to the accompanying drawings wherein: figure 1 is a side view of a lower rear portion of a vehicle having an endless link assembly according to the prior art; figure 2 is a side view of a worn track link according to the prior art; figure 3 is a plan view of a bearing element according to one aspect of the invention for the track link of figure 2; ) figure 4 is a side view of the bearing element of figure 3; figure 5 is a side view of a track link according to another aspect of the invention, repaired by the bearing element of figures 3 and 4; figure 6 is an end view of the track fink of figure 5; and figure 7 is a perspeciivé expivtieu view uf figuie &:

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

Referring to figures 1 and 2, the track link 10 according to the prior art comprises an elongate relatively flat body 12 having two connecting formations

«Tt WO 0029276 PCT/IBYYOIEZY 7 i 14 and 16 disposed towards opposite ends, for receiving connecting means in the form of pivots 4 (figure 1), for connecting the track link 10 to other identical track links.

As set out in the introduction, the body 12 further includes a bearing surface 26 for bearing against the idlers 8a and rollers 8b (figure 1) which support the vehicle 6. The bearing surface 26 is shown in figure 2 in a state of 100% wear.

The body 12 is further provided with two centrally disposed apertures 18 and 20, from which two holes 22 and 24 extend transversely in a direction away ¢ from the bearing surface 26. The track link 10 is connectable to a grouser shoe 9 (figure 1) forming part of the endless track assembly 2, by bolts extending through the holes 22 and 24. :

Referring to figures 3 to 7, in a method, according to a preferred embodiment of the invention, of repairing the worn track link 10, a bearing element 28 is provided. The bearing element 28 is shaped complimentary to the bearing surface 26 and comprises an elongate solid member having an upper bearing surface 30. The bearing element 28 is provided with a lower surface 31 (figure 4) which is adapted to cover the bearing surface 26. In a step of the method, the edge of the lower surface 31 and the edge of the upper surface 26 is ground

8 i . away, thus to provide a welding interface along the periphery of the lower surface 31 and along the upper surface 26. A central hole 32, extending through the bearing element 28, provides a further welding interface.

After the preparation of the welding interface, the bearing element 28 is disposed on the bearing surface 26 of the track link 10, to cover the bearing surface 26 and the bearing element 28 is then welded along the welding interface to the track link 10.

The thickness of the bearing element 28 is selected such that after repair of the track link 10, it is restored substantially to its original dimensions.

The repaired track link 10 can now be relocated in the endless link assembly 2 and be used as before. Should the bearing element again wear down to the state shown in figure 1, the above procedure can optionally be repeated. it wiii be appreciaied that mush msnsy san ba saved and pollution reduced hy repairing worn track links 10 with a bearing element 28 and method according to the invention, instead of discarding worn track links 10. Another advantage of the present invention is that the bearing element 28 can be made from a material which is relatively more resistant to wear than the body 12. As a result, the life of the track link can be extended to more than 100 % the original life of

( . + WO 00/29276 PCT/IRI9/01829 the track link.

Yet another advantage of the present invention is that the worn track links need not meet particular criteria in order to be rebuild, as bearing elements 28 of different thickness can be selected.

Claims

10 | Co CLAIMS

1. A method of repairing a worn track link of the type having a bearing surface, the method including the steps of providing a solid bearing element having a bearing surface; and securing the bearing element to the track link to cover the bearing surface of the track link.

2. A method according to claim 1 wherein the step of securing the bearing element to the track link includes the step of welding the bearing element to the track link.

: 3. A method according to claim 2 which includes the further step of providing an interface between the track link and the bearing element . prior to the step of welding.

4. A method of repairing a worn track link of the type having a bearing surface substantially as herein described with reference to figures 3 to

7.

5. A track link comprising a body having a bearing surface; and a solid bearing element also having a bearing surface, the bearing element being secured to the body to cover the bearing surface of the body.

6. A track link according to claim 5 wherein the bearing surface of the bearing element is complementary to the bearing surface of the body.

7. A track link according to claim 6 wherein the bearing element is welded to the body.

8. A track link according to claim 7 wherein the bearing element defines an interface along which it is welded to the track link.

9. A track link according to claim 8 wherein the interface comprises a peripheral groove formation.

10. A track link according to claim 9 wherein the interface further comprises a centrally disposed hole extending through the bearing element.

11. A track link according to any one of claims 5 to 10 wherein the bearing element is of a material which is relatively more resistant to wear than the body.

12. A track link substantially as herein described and as illustrated in figures 5to 7.

13. An endless link assembly comprising at least one track link having a bearing surface; and a bearing element also having a bearing surface, the bearing element being secured to the track link to cover the bearing surface of the track link.

14. An endless link assembly according to claim 13 wherein the bearing surface of the bearing element is complementary to the bearing surface of the track link.

15. An endless link assembly according to claim 13 or claim 14 wherein the bearing element is welded to the track link.

16. An endless link assembly according to claim 15 wherein the bearing element defines an interface along which it is welded to the track link.

17. An endless link assembly according to claim 16 wherein the interface LOMprises a peripitetdl Gioove formation. :

18. An endless link assembly according to claim 16 or claim 17 wherein the interface further comprises a centrally disposed hole extending through the bearing element.

. + WO 00/29276 PCT/IR99/01829 .

19. An endless link assembly according to any one of the preceding claims wherein the bearing element is of a material which is relatively more resistant to wear than the track link.

20. A bearing element for repairing a track link of the type comprising a body having a bearing surface, the bearing element comprising a solid member having a bearing surface which is complementary to the bearing surface of the track link; and an interface along which it is connectable to the frack link to cover the bearing surface of the track 10° link. : 21. A bearing element according to claim 20 wherein the interface comprises a peripheral groove formation.

22. A bearing element according to claim 21 wherein the interface further comprises a centrally disposed hole extending through the bearing element.

23. A bearing element according to any one of claims 20 to 22 which is of a material which is relatively more resistant to wear than the track link.

24, A bearing element substantially as herein described and as illustrated in figures 3to 7.