Patent ID: 7942584

Claim:
A wheel bearing apparatus comprising: an outer member formed with double row outer raceway surfaces on its inner circumferential surface; an inner member including a wheel hub having an integrally formed wheel mounting flange at one end and a cylindrical portion axially extending from the wheel mounting flange, at least one inner ring being fit onto the cylindrical portion of the wheel hub, the inner ring being formed with an inner raceway surface on its outer circumferential surface, said inner raceway surface arranged oppositely to one of the double row outer raceway surfaces; double row rolling elements rollably arranged between the outer and inner raceway surfaces, via cages; seals mounted in openings or annular spaces formed between the outer member and the inner member; and at least an inner-side seal of the seals comprises a slinger and an annular sealing plate, each having a substantially “L” shaped cross-section and arranged opposite to one another, the slinger comprises a cylindrical portion, fit onto the inner member, and a standing plate portion, extending radially outward from the cylindrical portion, the sealing plate comprises a metal core press fitted in the outer member and a sealing member integrally vulcanized adhered to the metal core; and the sealing member is formed with a plurality of side lips and a grease lip, each tip of said plurality of side lips slidingly contacts the standing plate portion of the slinger with a predetermined contacting load, and said grease lip, a tip of which slidingly contacts the cylindrical portion of the slinger with a predetermined frictional force, the frictional force of the grease lip is equal to or larger than the contacting load of the plurality of side lips in order to avoid the separation of the sealing plate and the slinger.