Wheel bearing apparatus for a vehicle

A vehicle wheel bearing apparatus comprising:

• an outer member formed, on its outer circumference, with a body mounting flange to be mounted on a body of a vehicle and on its inner circumference with double row outer raceway surfaces;
• an inner member including a wheel hub and an inner ring or an outer joint member of a constant velocity universal joint, the wheel hub is formed on its one end with a wheel mounting flange, its outer circumference includes one inner raceway surface opposing one of the double row outer raceway surfaces, a cylindrical portion axially extends from the inner raceway surface, and the inner ring or an outer joint member of the constant velocity universal joint is press-fit onto the cylindrical portion of the wheel hub and its outer circumference includes the other inner raceway surface opposing the other of the double row outer raceway surfaces;
• double row rolling element groups are freely rollably contained between the outer and inner raceway surfaces of the outer and inner members;
• and
• seal is adapted to be mounted within an outer side end of the outer member, the seal has an integrally formed side lip extending radially outwardly toward its tip and in sliding contact with an inner side base portion of the wheel mounting flange, via a predetermined interference, an initial maximum diameter of the side lip is formed with a smaller diameter than that of a maximum diameter of the seal and a difference between the initial maximum diameter of the side lip and the maximum diameter of the seal is set at least 1 mm on one side.