ROLLING BEARING UNIT FOR SUPPORTING WHEEL

摘要

PROBLEM TO BE SOLVED: To provide a structure capable of securing the rolling fatigue life of a first inner ring raceway 7 at low cost. SOLUTION: A hub 2b of a carbon steel having a carbon content of 0.45 or more wt.% is connected to an inner ring of a high carbon steel through a caulked part 19 formed at the end of the hub 2b. For the hub 2b, a sloped lattice portion including the first inner ring raceway 7 is hardened. The inner ring 3 is hardened to the core part thereof. At least the portion of the hub 2b forming the caulked part 19 is not hardened. COPYRIGHT: (C)2004,JPO