# US 8,770,677 B2 · Compound rim assembly for idler in an undercarriage system of a track-type machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,770,677 B2 - Document ID: US8770677B2 - Status: Granted - Kind: B2 - Application number: 12/974,474 - Filed: 2010-12-21 - Published: 2012-06-21 - Granted: 2014-07-08 - Earliest claimed: 2010-12-21 - Assignees: Caterpillar Inc. - Applicants: Alexei P. Yelistratov - Inventors: Alexei P. Yelistratov - Web page: https://patentgrep.com/patent/US8770677B2 ## CPC - B62D 55/145: {Rollers with replaceable wear rings or rims (driving sprockets with replaceable rims B62D55/12)} - 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 compound rim assembly for a rotatable idler in an undercarriage system of a track-type machine includes a one-piece annular base configured for mounting the compound annular rim assembly upon an outer peripheral surface of an idler hub. The one-piece annular base is formed of a relatively lower hardness metallic material, and the compound rim assembly further includes a first annular track contacting rim a second annular track contacting rim positioned upon the one-piece base and being formed of a relatively higher hardness metallic material. The compound rim assembly further includes a track guiding ring trapped axially between the first and second annular track contacting rims and abutting the outer cylindrical surface of the one-piece annular base, the track guiding ring being formed of a non-metallic material and projecting radially outward of the first and second annular track contacting rims. ## Claims ### Claim 1 A compound rim assembly for a rotatable idler in an undercarriage system of a track-type machine comprising: a one-piece annular base configured for mounting the compound annular rim assembly upon an outer peripheral surface of an idler hub, the one-piece annular base being formed of a relatively lower hardness metallic material, and having a cylindrical inner surface defining a center axis, a cylindrical outer surface concentric with the cylindrical inner surface, and a first and a second axial end surface; the one-piece annular base further including an axial thickness between the first and second axial end surfaces, and a radial thickness between the inner and outer cylindrical surfaces, the radial thickness being less than the axial thickness; a first annular track contacting rim positioned upon the outer cylindrical surface at a location adjacent the first axial end surface, and a second annular track contacting rim positioned upon the outer cylindrical surface at a location adjacent the second axial end surface, each of the first and second annular track contacting rims being formed of a relatively higher hardness metallic material and being welded to the one-piece annular base; and a track guiding ring trapped axially between the first and second annular track contacting rims and abutting the outer cylindrical surface of the one-piece annular base, the track guiding ring being formed of a non-metallic material and projecting radially outward of the first and second annular track contacting rims. ### Claim 2 (depends on 1) The compound rim assembly of claim 1 further comprising a first interference coupling between the one-piece annular base and the first annular track contacting rim, and a second interference coupling between the one-piece annular base and the second annular track contacting rim. ### Claim 3 (depends on 2) The compound rim assembly of claim 2 further comprising a first circular edge weld attaching the first annular track contacting rim to the one-piece annular base, and a second circular edge weld attaching the second annular track contacting rim to the one-piece annular base. ### Claim 4 (depends on 3) The compound rim assembly of claim 3 wherein the track guiding ring includes a one-piece ring slip fitted upon the outer cylindrical surface. ### Claim 5 (depends on 3) The compound rim assembly of claim 3 having a total number of welds equal to two. ### Claim 6 (depends on 3) The compound rim assembly of claim 3 wherein: the one-piece annular base includes a first beveled surface extending from the outer cylindrical surface to the first axial end surface, and a second beveled surface extending from the outer cylindrical surface to the second axial end surface; and the first circular edge weld includes weld material contacting the first beveled surface and the first annular track contacting rim, and the second circular edge weld includes weld material contacting the second beveled surface and the second annular track contacting rim. ### Claim 7 (depends on 6) The compound rim assembly of claim 6 wherein the compound rim assembly consists essentially of the one-piece annular base, the first and second annular track contacting rims, the weld material, and the track guiding ring. ### Claim 8 (depends on 3) The compound rim assembly of claim 3 wherein: the axial thickness is equal to between about 200 millimeters and about 300 millimeters; and the track guiding ring includes an outer ring surface defining an outer diameter dimension of the compound rim assembly, and the outer diameter dimension is equal to between about 700 millimeters and about 800 millimeters. ### Claim 9 A remanufactured idler for an undercarriage system in a track-type machine comprising: a hub including an outer peripheral surface, an inner peripheral surface defining an idler mounting bore, and a compound rim assembly mounted upon the hub, the compound rim assembly including a first annular track contacting rim, a second annular track contacting rim, and a track guiding ring; a weld attaching the compound rim assembly to the hub; the hub being formed of a relatively lower hardness metallic material, the first and second annular track contacting rims being formed of a relatively higher hardness metallic material, and the track guiding ring being formed of a non-metallic material; and the track guiding ring being trapped axially between the first and second annular track contacting rims, and projecting radially outward of the first and second annular track contacting rims; wherein the weld includes a first circular edge weld, and further comprising a second circular edge weld; wherein the compound rim assembly further includes a one-piece annular base mounted upon the outer peripheral surface, and wherein the first and second circular edge welds attach the one-piece annular base to the hub. ### Claim 10 (depends on 9) The remanufactured idler of claim 9 wherein the hub further includes a first and a second axial side, and wherein the outer peripheral surface includes a cylindrical surface and extends from the first axial side to the second axial side. ### Claim 11 (depends on 10) The remanufactured idler of claim 10 further comprising a third circular edge weld attaching the first annular track contacting rim to the one-piece annular base, and a fourth circular edge weld attaching the second annular track contacting rim to the one-piece annular base. ### Claim 12 (depends on 11) The remanufactured idler of claim 11 having a total number of welds equal to four. ### Claim 13 (depends on 9) The remanufactured idler of claim 9 wherein the track guiding ring includes a one-piece ring. ### Claim 14 (depends on 9) The remanufactured idler of claim 9 wherein the first and second circular edge welds attach the first and second annular track contacting rims, respectively, to the hub. ### Claim 15 An undercarriage system for a track-type machine comprising: a ground engaging track including a plurality of track shoes, a plurality of track links coupling together the track shoes in an endless track chain, and a plurality of track pins coupled with the track links; an idler for the ground engaging track including an idler body having a hub formed of a relatively lower hardness metallic material, and a compound rim assembly mounted upon the hub, the compound rim assembly including a first annular track contacting rim, a second annular track contacting rim, and a track guiding ring; a weld attaching the compound rim assembly to the hub; the hub being formed of a relatively lower hardness metallic material, the first and second annular track contacting rims being formed of a relatively higher hardness metallic material, and the track guiding ring being formed of a non-metallic material; and the track guiding ring being trapped axially between the first and second annular track contacting rims, and projecting radially outward of the first and second annular track contacting rims such that the track guiding ring contacts the plurality of track pins; wherein: the compound rim assembly includes a one-piece annular base having a cylindrical inner surface interference fitted upon the hub, and a cylindrical outer surface; each of the first and second annular track contacting rims are interference fitted upon the cylindrical outer surface; and the weld includes a first circular edge weld, the idler further including second circular edge weld, and the first and second circular edge welds attaching the first and second annular track contacting rims to the one-piece annular base, respectively.