Rotatable idler for undercarriage system in a track-type machine

A method of making a rotatable idler for an undercarriage system in a track-type machine comprising the steps of:

• capping a one-piece hub formed of a relatively lower hardness metallic material and defining an axis of rotation with a compound annular rim formed of a relatively higher hardness metallic material;
• sandwiching a radially projecting outer spine of the one-piece hub axially between abutting rim components of the compound annular rim during capping the one-piece hub;
• and
• attaching the compound annular rim to the one-piece hub;
• wherein the step of capping includes reversibly coupling the compound annular rim with the one-piece hub, and the step of attaching includes irreversibly coupling the compound annular rim with the one-piece hub.

An undercarriage system for a track-type machine comprising:

• a ground engaging track including a plurality of track shoes, and a plurality of track links coupling together the track shoes in an endless track chain;
• 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 annular rim capping the hub and being formed of a relatively higher hardness metallic material;
• the hub including an inner peripheral surface defining an idler mounting bore, an outer peripheral surface, and a radially projecting outer spine, and the radially projecting outer spine having an annular configuration and being concentric with the idler mounting bore;
• the compound annular rim having an inner rim surface, a track contacting outer rim surface having a crowned profile, and first and second abutting rim components sandwiching the radially projecting outer spine, each of the first and second abutting rim components having a stepped profile and including a portion of the inner rim surface and a portion of the track contacting outer rim surface;
• and
• a first interference coupling between the first rim component and the hub, and a second interference coupling between the second rim component and the hub.