Patent ID: 8770676

Claim:
A rotatable idler for an undercarriage system in a track-type machine comprising: a one-piece hub defining an axis of rotation and being formed of a relatively lower hardness metallic material, the one-piece hub having an outer peripheral surface, a first and a second end surface located on first and second axial sides of the one-piece hub, an inner peripheral surface defining an idler mounting bore, and a radially projecting outer spine, the radially projecting outer spine having an annular configuration circumferential of the axis of rotation, and being positioned axially between the first and second end surfaces; and a compound annular rim coaxial with the one-piece hub and being formed of a relatively higher hardness metallic material, the compound annular rim capping the one-piece hub and including an inner rim surface, and a track contacting outer rim surface having a crowned profile; the compound annular rim further including a first and a second rim component, each of the rim components having a stepped profile, an outboard shoulder segment relatively tightly fitted upon the outer peripheral surface and located axially outward of the radially projecting outer spine, and an inboard crown segment relatively loosely fitted upon the outer peripheral surface and axially overlapping the radially projecting outer spine.