| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a wheel bearing preventing generation of fretting wear on a gear part and bearing shakiness by rigidly fixing an inner-ring member to a hub wheel. <P>SOLUTION: The inner-ring member 5 integrally includes a cylindrical stem part 8 axially extending from an inside running face 5a via a shoulder part 7. The cylindrical stem part 8 includes a socket joint 8a which a small-diameter step 4b of the hub wheel 4 fits cylindrically in and a fitting part 8b formed on the end of the socket joint 8a. The gear part 9 is integrally formed with the outer periphery of the end of the inner-ring member 5. A predetermined hardened layer with surface hardness in the range of 58-64 HRC through induction hardening is formed from the gear part 9 to the socket joint 8a. The fitting part 8b has green surface hardness just after it is forged. A hardened, uneven part 12 is formed on the inner side of the hub wheel 4. The fitting part 8b of the inner-ring member 5 is radially expanded and made to bite the uneven part 12 to be caulked, thereby integrally and plastically connecting the inner-ring member 5 to the hub wheel 4. <P>COPYRIGHT: (C)2012,JPO&INPIT |
