Patent ID: 7708353

Claim:
An axle bearing apparatus comprising: a hub shaft that includes a wheel-mounting flange formed at an outer side thereof and a cylindrical portion formed on an inner side thereof, a plurality of bolt holes being formed through the flange; a bearing portion that is press-fitted on the cylindrical portion of the hub shaft and includes an inner ring, an outer ring and rolling elements disposed between the inner and outer rings; a slinger that includes a through hole formed through a central portion thereof and has an outer diameter generally equal to an outer diameter of the flange, wherein the through hole is fitted on the cylindrical portion, and the slinger is press-clamped to an inner side surface of the flange by bolts press-fitted respectively in the plurality of bolt holes; a plurality of O-rings interposed between the flange and the slinger; and ring-shaped grooves configured to receive the plurality of O-rings formed in an inner side surface of the flange in concentric relation to each other, the ring-shaped grooves being disposed respectively at inner and outer peripheral sides of the bolt holes.