| 摘要 |
PROBLEM TO BE SOLVED: To achieve such a structure that damages, such as cracks, hardly occur in a stepped part 18 of an outward flange part 10 of a hub body 7, and to provide a method of manufacturing the same. SOLUTION: A quench hardening layer 17 is formed in a part from an inner ring race 9a close to the outward flange part 10 to an inner part of the outward flange part 10 in the radial direction among an outer peripheral surface of the hub body 7. A position of boundary between the quench hardening layer 17 and the other part is set at a position deviated from the stepped part 18. The boundary where residual stresses occur and strength is reduced due to recrystallization caused by heat treatment for quenching is deviated from the stepped part 18 where the stresses are concentrated, so that the above problems are solved. COPYRIGHT: (C)2010,JPO&INPIT |
