Patent ID: 7648284

Claim:
A vehicle bearing apparatus comprising: an outer member formed with double row outer raceway surfaces on an inner peripheral surface; an inner member including a wheel hub having an integrally formed wheel mounting flange at one end of the inner member, a cylindrical portion axially extending from the wheel mounting flange, one inner ring formed with one of double row inner raceway surfaces opposing the double row outer raceway surfaces and adapted to be press-fit onto the cylindrical portion of the wheel hub; double row rolling elements freely rollably contained between the outer and inner raceway surfaces, respectively, of the outer and inner members, the inner ring being axially immovably secured relative to the wheel hub by a caulked portion formed by plastically deforming the end of the axially extending cylindrical portion radially outward and forming a hoop stress in the inner ring, said hoop stress is limited to less than 300 MPa preventing the generation of a delayed fracture in said inner ring; a partition wall formed in the axially extending cylindrical portion of the wheel hub, said partition wall positioned immediately below the center of the inner ring on the inboard side in an axial direction, said partition wall positioned to be subjected to a load applied to the inner raceway surface of an inboard side raceway surface of the double row inner raceway surfaces so that the partition wall directly receives the load that is generated in the bearing along the bearing contact angle and a hollow portion formed within the cylindrical portion at a portion outboard from the partition wall.