| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a wheel bearing unit capable of preventing balls from generating scratches at the time of assembling and improving bearing life despite its non-separable structure that an inner ring is not separated from an outer ring at the time of transportation and its handling. <P>SOLUTION: The wheel bearing unit is a matched back-to-back angular contact bearing type, and has a counter bore section 9 which is adjacent to a raceway surface 4 of the outer ring 1 and projects a bore surface at a bore side rather than a groove bottom diameter of a raceway surface 4 of the outer ring. A seal mounting surface 1a being greater than the bore of the counter bore section 9 is provided adjacent to an outer ring end side of the counter bore section 9. A bore side section at a step face 9b between the counter bore section 9 and seal mounting surface 1a is a tapered-off surface 9ba in a tapered shape, and provides a sectioned arc chamfer section 9c at an edge section between the tapered-off surface 9ba and a bore surface 9a of the counter bore section 9. <P>COPYRIGHT: (C)2007,JPO&INPIT |
