Wheel bearing apparatus

A wheel bearing apparatus comprising:

• an outer member integrally formed with double row outer raceway surfaces on its inner circumference;
• an inner member including a wheel hub and at least one inner ring, the wheel hub is integrally formed, on its one end, with a wheel mounting flange, a cylindrical portion axially extends from the wheel mounting flange, the inner ring is press fit onto the cylindrical portion of the wheel hub, the wheel hub and the inner ring are formed on their outer circumferences, respectively, with one double row inner raceway surfaces that oppose the double row outer raceway surfaces;
• double row rolling elements are freely rollably contained between the inner raceway surfaces and outer raceway surfaces of the inner member and outer member;
• a pulser ring is fit onto the outer circumference of the inner ring;
• a seal is mounted on the outer-side end of the outer member, a protecting cover is mounted on the inner-side end of the outer member, the seal and protective cover close and seal annular openings formed between the outer member and the inner member at both their ends;
• the protecting cover is formed with a cup-shaped configuration by press working a non-magnetic steel sheet;
• the protective cover further comprises a cylindrical fitting portion, a disk-shaped shielding portion, a stepped portion, and a bottom portion;
• the cylindrical fitting portion is press-fit into the inner circumference of the inner-side end of the outer member, the disk-shaped shielding portion extends radially inward from the fitting portion via a radially reducing portion, the inner-side surface of the shielding portion is adapted to be arranged close to or in contact with a rotation speed detecting sensor, and the bottom portion is continuous with the shielding portion via the stepped portion to close the inner-side end of the inner member;
• and
• a full deflection of the side surface of the shielding portion caused by a load same as that applied to the protecting cover when it is press-fit into the outer member is limited to a predetermined value or less.