Patent ID: 8186885
Filing Date: 2012-05-29
Classification: B60B,F16C,F16D,Y10T

Abstract:
1. A vehicle wheel bearing apparatus formed as a unit of a wheel hub, a rolling bearing and a constant velocity universal joint comprising: an outer member formed on its inner surface with double row outer raceway surfaces; an inner member including the wheel hub and the outer joint member of the constant velocity universal joint, the wheel hub having a wheel mounting flange integrally formed at one end and one inner raceway surface formed on its outer circumferential surface arranged opposite to one of the double row outer raceway surfaces, a cylindrical portion axially extending from said inner raceway surface, said outer joint member being fit into the wheel hub and formed on its outer circumferential surface with another inner raceway surface arranged opposite to the other raceway surface of the double row outer raceway surfaces and a shaft portion axially extending from said other inner raceway surface; double row rolling elements freely rollably held between the outer and inner raceway surfaces; a pitch circle diameter of the outer side rolling elements of the double row rolling elements is different from a pitch circle of the inner side rolling elements of the double row rolling elements, the outer side rolling elements forming a smaller pitch circle diameter and the inner side rolling elements forming a larger pitch circle diameter, at least the outer side rolling elements of the smaller pitch circle diameter of the double row rolling elements are tapered rollers, and the inner side rolling elements of the larger pitch circle diameter of the double row rolling elements are balls; and a number of the inner side rolling elements in the larger pitch circle diameter is set larger than a number of the outer side rolling elements in the smaller pitch circle diameter reducing the axial size of the bearing apparatus while maintaining loading capacity or balance rigidity of the bearing apparatus.