# US 8,465,110 B2 · Machine and track assembly for use therewith > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,465,110 B2 - Document ID: US8465110B2 - Status: Granted - Kind: B2 - Application number: 13/443,353 - Filed: 2012-04-10 - Published: 2012-08-02 - Granted: 2013-06-18 - Earliest claimed: 2007-10-18 - Assignees: Caterpillar Inc. - Applicants: Donovan Clarke; Kevin Steiner; Victor M. Penrod; Roger L. Recker - Inventors: Donovan Clarke; Kevin Steiner; Victor M. Penrod; Roger L. Recker - Web page: https://patentgrep.com/patent/US8465110B2 ## CPC - B62D 55/145: {Rollers with replaceable wear rings or rims (driving sprockets with replaceable rims B62D55/12)} - B62D 55/21: Links connected by transverse pivot pins - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) ## Abstract A track assembly for a machine includes a track having inner track seals, a rotatable track engaging element such as an idler or drive sprocket and a contact interface for protecting the seals during guiding the track about the rotatable element. The contact interface may include sacrificial wear material on the rotatable element and sacrificial wear material on corresponding track links. The contact interface may have a configuration based on a location of the seals, and is adapted to inhibit wear of the track links in regions adjacent the seals. In another aspect, the contact interface is a guide interface. ## Claims ### Claim 1 A rotatable track engaging element, for guiding or driving a ground engaging track having first and second chain assemblies including track pins received in bores formed in inboard track links, bushings positioned on the track pins, and inner track seals positioned in the bores and being adjacent to exposed seal regions of the inboard track links facing a track guiding space, the rotatable track engaging element comprising: a body defining an axis of rotation and including an inner diameter surface, an outer diameter surface, and first and second axial sides extending from the inner diameter surface to the outer diameter surface, the body further having a contact interface including seal protecting wear surfaces positioned on each of the axial sides; each of the axial sides includes an outboard surface extending a first radial distance from the corresponding seal protecting wear surface to the outer diameter surface, and an inboard surface extending a second, greater radial distance from the corresponding seal protecting wear surface to the inner diameter surface; and wherein each of the inboard surfaces includes a lower axial elevation, each of the outboard surfaces includes a middle axial elevation, and each of the seal protecting wear surfaces includes a higher axial elevation; and wherein each of the first and second axial sides further includes an axially protruding step, and each of the axially protruding steps includes, a face whereupon the seal protecting wear surface is located, disposed at a non-perpendicular face angle relative to the axis of rotation and being formed of a sacrificial wear material, whereby the contact interface directs contact between the body and the inboard track links away from the exposed seal regions during operating the ground engaging track. ### Claim 2 (depends on 1) The rotatable track engaging element of claim 1 wherein the faces each include a conical face. ### Claim 3 (depends on 2) The rotatable track engaging element of claim 2 comprising an idler in which the body includes a one-piece idler body, and wherein the outer diameter surface is positioned at a constant radial distance from the axis of rotation. ### Claim 4 (depends on 3) The rotatable track engaging element of claim 3 wherein each of the outboard surfaces adjoin the outer diameter surface at a first corner and a second corner, respectively. ### Claim 5 A rotatable track engaging element, for guiding or driving a ground engaging track having first and second chain assemblies including track pins received in bores formed in inboard track links, bushings positioned on the track pins, and inner track seals positioned in the bores and being adjacent to exposed seal regions of the inboard track links facing a track guiding space, the rotatable track engaging element comprising: a body defining an axis of rotation and including an inner diameter surface, an outer diameter surface, and first and second axial sides extending from the inner diameter surface to the outer diameter surface and each including a seal protecting wear surface; each of the axial sides includes an outboard surface extending a first radial distance from the corresponding seal protecting wear surface to the outer diameter surface, and an inboard surface extending a second, greater radial distance from the corresponding seal protecting wear surface to the inner diameter surface; each of the inboard surfaces includes a lower axial elevation, each of the outboard surfaces includes a middle axial elevation, and each of the seal protecting wear surfaces includes a higher axial elevation; and each of the first and second axial sides further includes an axially protruding step having a face whereupon the corresponding seal protecting wear surface is located, and each of the faces being disposed at a non-perpendicular face angle relative to the axis of rotation, for directing contact between the body and the inboard track links away from the exposed seal regions during operating the ground engaging track. ### Claim 6 (depends on 5) The rotatable track engaging element of claim 5 wherein the body includes a one-piece body. ### Claim 7 (depends on 6) The rotatable track engaging element of claim 6 wherein the outer diameter surface is positioned at a constant radial distance from the axis of rotation. ### Claim 8 (depends on 7) The rotatable track engaging element of claim 7 wherein the faces each include a conical face. ### Claim 9 (depends on 5) The rotatable track engaging element of claim 5 wherein each of the axially protruding steps is curved about the axis of rotation. ### Claim 10 A rotatable track engaging element for driving or guiding a ground engaging track comprising: a body defining an axis of rotation and including an inner diameter surface, an outer diameter surface, and first and second axial sides extending from the inner diameter surface to the outer diameter surface and each having a seal protecting wear surface; each of the axial sides further includes an outboard surface extending a first radial distance from the corresponding seal protecting wear surface to the outer diameter surface, and an inboard surface extending a second, greater radial distance from the corresponding seal protecting wear surface to the inner diameter surface; each of the inboard surfaces includes a lower axial elevation, each of the outboard surfaces includes a middle axial elevation, and each of the seal protecting wear surfaces includes a higher axial elevation; and each of the first and second axial sides further includes an axially protruding step, for directing contact between the body and the ground engaging track away from exposed seal regions in inboard track links of the ground engaging track, and each of the axially protruding steps having a face whereupon the seal protecting wear surface is located, disposed at a non-perpendicular face angle relative to the axis of rotation and being formed of a sacrificial wear material. ### Claim 11 (depends on 10) The rotatable track engaging element of claim 10 wherein the body includes a one-piece body. ### Claim 12 (depends on 11) The rotatable track engaging element of claim 11 comprising an idler where the outer diameter surface is positioned at a constant radial distance from the axis of rotation. ### Claim 13 (depends on 12) The rotatable track engaging element of claim 12 wherein each of the axially protruding steps is curved about the axis of rotation. ### Claim 14 (depends on 10) The rotatable track engaging element of claim 10 wherein each of the faces includes a conical face. ### Claim 15 (depends on 14) The rotatable track engaging element of claim 14 wherein each of the outboard surfaces defines a plane oriented substantially normal to the axis of rotation. ### Claim 16 (depends on 14) The rotatable track engaging element of claim 14 wherein each of the axially protruding steps extends a third radial distance between the corresponding inboard and outboard surfaces which is less than the first radial distance.