Patent ID: 7832942

Claim:
A wheel bearing apparatus for a vehicle comprising: an outer member formed, on its inner circumference, with double row outer raceway surfaces; an inner member including a wheel hub and at least one inner ring fit onto a cylindrical portion of the wheel hub or an outer raceway surface of a constant velocity universal joint, the wheel hub includes a wheel mounting flange formed integrally at one end, a cylindrical portion axially extends from the wheel mounting flange, the inner member is formed, on its outer circumference, with double row inner raceway surfaces arranged opposite to said double row outer raceway surfaces; double row rolling element groups are freely rollably contained between said inner and outer raceway surfaces of the inner member and the outer member; and a pitch circle diameter of the rolling element group near to the wheel mounting flange is larger than a pitch circle diameter of the double row rolling element group away from the wheel mounting flange, a maximum diameter of the outer raceway surface of the smaller diameter side of the double row outer raceway surfaces of the outer member is substantially the same as an inner diameter of a shoulder portion of the outer diameter side, a size of each rolling element of the group near to the wheel mounting flange is different from that of each rolling element of the group away from the wheel mounting flange, and a number of rolling elements of the group near to the wheel mounting flange is larger than a number of rolling elements of the group away from the wheel mounting flange.