Patent ID: 8172342

Claim:
A rotatable track engaging idler, for guiding 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 idler comprising: an idler body defining an axis of rotation and including an inner diameter surface, an outer diameter surface positioned at a constant radial distance from the axis of rotation, and first and second axial sides extending in a radial direction from the inner diameter surface to the outer diameter surface, the idler 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 and a lower material hardness, each of the outboard surfaces includes a middle axial elevation and a higher material hardness, and each of the seal protecting wear surfaces includes a higher axial elevation and a higher material hardness, whereby the contact interface directs contact between the idler body and the inboard track links away from the exposed seal regions and limits a wear rate of the seal protecting wear surfaces in response to contacting the inboard track links.