Bushingless track pin for a track type vehicle
AssigneeCaterpillar Inc.
InventorWilliam Henry Baar, III
Life of this patent
Estimating the term…
Abstract
A bushingless track pin is disclosed. The track pin includes a hardened outer layer and a relatively softer inner core. The track pin may be formed using high carbon steel, which in some cases may be substantially spheroidal martensite crystal structure. A track pin may be formed using the high carbon steel, followed by a hardening process. In some examples, an optional induction hardening process may thereafter be performed on the inner surface most proximal to the central hole of the track pin if needed. The hardening on the inner surface may harden the outer portion while tempering the core portion of the track pin.
Claims18
A track chain assembly comprising:
- a first link and a second link;
- and
- a track pin joining the first link to the second link, the track pin having a unitary construction, wherein a first length of the track pin has a substantially constant first diameter and a second length of the track pin has a substantially constant second diameter, the track pin comprising:
- a first layer having a thickness up to 10 mm, the first layer having a first hardness within an HRC range from 50 HRC to 70 HRC;
- a second layer having a second hardness that is less than the first hardness, wherein the track pin excludes an interface with a bushing;
- a first sealed composite bearing coupled to the first length of the track pin at a first end of the track pin;
- a second sealed composite bearing coupled to the first length of the track pin at the first end of the track pin;
- a third sealed composite bearing coupled to the second length of the track pin at a second end of the track pin;
- and
- a fourth sealed composite bearing coupled to the second length of the track pin at the second end of the track pin.
A method for producing a track pin, the method comprising:
- forming the track pin having a unitary construction using a high carbon steel, wherein the track pin excludes an interface with a bushing, wherein a first length of the track pin has a substantially constant first diameter and a second length of the track pin has a substantially constant second diameter;
- differentially hardening the track pin to form:
- a first layer having a thickness up to 10 mm, the first layer having a first hardness within an HRC range from 50 HRC to 70 HRC;
- a second layer having a second hardness less than the first hardness;
- and
- coupling:
- a first sealed composite bearing to the first length of the track pin at a first end of the track pin;
- a second sealed composite bearing to the first length of the track pin at the first end of the track pin;
- a third sealed composite bearing to the second length of the track pin at a second end of the track pin;
- and
- a fourth sealed composite bearing to the second length of the track pin at the second end of the track pin.
A track pin having a unitary construction, comprising:
- a first length having a substantially constant first diameter;
- a second length having a substantially constant second diameter
- a first layer having a thickness up to 10 mm, the first layer having a first hardness within an HRC range from 50 HRC to 70 HRC;
- a second layer having a second hardness with a second hardness less than the first hardness, wherein the track pin excludes an interface with a bushing;
- a first sealed composite bearing coupled to the first length of the track pin at a first end of the track pin;
- a second sealed composite bearing coupled to the first length of the track pin at the first end of the track pin;
- a third sealed composite bearing coupled to the second length of the track pin at a second end of the track pin;
- and
- a fourth sealed composite bearing coupled to the second length of the track pin at the second end of the track pin.
Dependencies are inferred from the claim text.