US Patent 8002474 Wheel bearing apparatus

A vehicle wheel bearing apparatus has an outer member, an inner member with at least one inner ring, double row rolling elements, and a constant velocity universal joint torque transmittably inserted into a wheel hub and axially separably connected by a securing nut. A shoulder of an outer joint member of the constant velocity universal joint abuts against a larger end face of the inner ring. The larger end face of the inner ring is formed as a ground surface. An end face of the shoulder of the outer joint member abutted against the larger end face is formed as a ground surface or a lathe-turned surface. The surface roughness Ra of at least the larger end face of the inner ring is limited to a range within 0.1˜0.3.