Variable hardening depth in track link for a ground-engaging track

Patent metadata

Field	Value
Publication number	US-9290217-B2
Application number	US-201313933491-A
Country	US
Kind code	B2
Filing date	Jul 2, 2013
Priority date	Jul 2, 2013
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A track link for a ground-engaging track includes an elongate link body having a lower hardness material forming a lower mounting surface for mounting a track shoe, and a sacrificial higher hardness material forming an upper rail surface for contacting rotatable track engaging elements. The lower hardness and higher hardness materials transition at a material interface within the elongate link body, and the material interface is longitudinally non-uniform, such that the sacrificial higher hardness material has a varying depth from the upper rail surface to retard scalloping.

First claim

What is claimed is:

1. A ground-engaging track for a machine comprising:
a track chain assembly including a first track chain and a second track chain extending in parallel with the first track chain, the first and second track chains each including a plurality of elongate track links having a lower mounting surface for mounting a track shoe, and an upper rail surface configured to contact a rotating track-engaging element in the machine;
each elongate link of the plurality of elongate track links further including a lower hardness material forming the lower mounting surface, and a sacrificial higher hardness material forming the upper rail surface, the lower mounting surface facing away from the upper rail surface in a height direction, a hardness of the sacrificial higher hardness material being greater than a hardness of the lower hardness material,
the sacrificial higher hardness material transitioning to the lower hardness material at a material interface within the elongate link,
the sacrificial higher hardness material having a first thickness and a second thickness each of which extending in the height direction from the upper rail surface to the material interface, the first thickness being different from the second thickness, the first thickness having a first hardness extending therethrough, the second thickness having a second hardness extending therethrough, wherein the first hardness is substantially equal to the second hardness.

2. The track of claim 1 , wherein each elongate link of the plurality of elongate track links defines a first track pin bore and a second track pin bore spaced from the first track pin bore in a longitudinal direction, each of the first and second track pin bores extending through the elongate link in a lateral direction, wherein the lateral direction, the longitudinal direction, and the height direction are angularly offset from one another, the material interface extending in the longitudinal and the lateral directions through the elongate link between the upper rail surface and the first and second track pin bores, the track further comprising a plurality of track pins, each track pin of the plurality of track pins being received within one of the track pin bores and coupling together the first and second track chains.

3. The track of claim 2 , wherein the lower hardness material has a varying depth extending from the lower mounting surface to the material interface, the varying depth of the lower hardness material defining a curving longitudinal contour having a plurality of peaks and a plurality of valleys.

4. The track of claim 3 , wherein each elongate link of the plurality of elongate track links further defines a first and a second window each located longitudinally between the first and the second track pin bores in the longitudinal direction, each elongate link including a vertical strut located between the first and the second windows in the longitudinal direction, and wherein the curving longitudinal contour forms a center valley coincident with the vertical strut in the longitudinal direction.

5. The track of claim 4 , wherein the center valley includes a deepest valley of the plurality of valleys, from the upper rail surface.

6. The track of claim 3 , wherein the curving longitudinal contour forms a first peak aligned with the first track pin bore in the longitudinal direction, and a second peak aligned with the second track pin bore in the longitudinal direction.

7. The track of claim 2 , wherein the plurality of elongate track links in the first track chain are mirror images of the plurality of elongate track links in the second track chain, and the track further comprises
a plurality of track pins coupling together the first and second track chains, each track pin of the plurality of track pins being received within one of the track pin bores, and
a plurality of bushings positioned upon the plurality of track pins.

8. The track of claim 7 , wherein the upper rail surface has a center section extending between a first end section and a second end section, the second end section being offset from the first end section in the lateral direction, wherein the upper rail surface has a first upper rail surface width corresponding to the first end section, a second upper rail surface width corresponding to the second end section, and a third upper rail surface width corresponding to the center section, the third upper rail surface width being greater than each of the first upper rail surface width and the second upper rail surface width.

9. The track of claim 8 , wherein the center section of the upper rail surface having the first thickness of the sacrificial higher hardness material, and the first end section and the second end section of the upper rail surface having the second thickness of the sacrificial higher hardness material, the first thickness being greater than the second thickness.

10. A track link for a ground-engaging track in a machine comprising:
an elongate link body including an inboard side and an outboard side each extending between first and second link body ends each having formed therein a track pin bore communicating between the inboard and outboard sides and configured to receive a track pin for coupling the elongate link body with adjacent elongate link bodies in a track chain;
the elongate link body further including a lower mounting surface for mounting a track shoe, and an upper rail surface configured to contact a rotating track-engaging element in the machine;
the elongate link body further including a lower hardness material forming the lower mounting surface, and a sacrificial higher hardness material forming the upper rail surface, the lower mounting surface facing away from the upper rail surface in a height direction, a hardness of the sacrificial higher hardness material being greater than a hardness of the lower hardness material, the sacrificial higher hardness material transitioning to the lower hardness material at a material interface within the elongate link body;
the sacrificial higher hardness material having a first thickness and a second thickness each of which extending in the height direction from the upper rail surface to the material interface, the first thickness being different from the second thickness, the first thickness having a first hardness extending therethrough, the second thickness having a second hardness extending therethrough, wherein the first hardness is substantially equal to the second hardness.

11. The track link of claim 10 , wherein the elongate link body defining a first adjacent window and a second adjacent window located between the first track pin bore and the second track pin bore, the elongate link body including a vertical strut located between the first adjacent window and the second adjacent window, and wherein the varying depth of the sacrificial higher hardness material is greatest at a location coincident with the vertical strut in the height direction.

12. The track link of claim 10 , wherein the upper rail surface is substantially planar and includes a center section extending between a first end section and a second end section laterally offset from the first end section, wherein the upper rail surface has a first upper rail surface width corresponding to the first end section, a second upper rail surface width corresponding to the second end section, and a third upper rail surface width corresponding to the center section, the third upper rail surface width being greater than each of the first upper rail surface width and the second upper rail surface width.

13. The track link of claim 12 , wherein the center section of the upper

Assignees

• Caterpillar Inc
• Caterpillar Inc

Inventors

• Steiner Kevin Lee
• Thorson Timothy Arthur
• Diekevers Mark Steven
• Brewer Caroline Marie
• Kaufmann Gregory J
• Akinlua Temitope Olayemi

Classifications

• B62D55/21 Primary

  Links connected by transverse pivot pins · CPC title

• B62D55/202

  Wheel engaging parts; Wheel guides on links · CPC title

• C21D1/10

  by electric induction · CPC title

• C21D1/42

  Induction heating · CPC title

• Y02P10/25

  Process efficiency · CPC title