| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a rolling bearing unit for supporting a wheel which has an excellent fatigue strength and is hardly damaged even if the big load is given, which is hardly damaged when manufacturing. <P>SOLUTION: The rolling bearing unit 1 for supporting a wheel is equipped with a hub race 2, an inner race 3 fixed to the hub race 2 integrally, an outer race 4 and rolling bodies 5, 5 of double rows. The raceway face formed on the outer face of the hub race 2 and the outer face of the inner race 3 and the raceway face formed on the inner circumference face of the outer race 4 are opposed and a plurality of rolling bodies 5 are arranged to rolling free between both opposed raceways. Moreover, a hardened layer 22 by high-frequency hardening is formed on the outer face of the hub race 2 and the inner face of the outer race 4. The hub race 2, the inner race 3 and the outer race 4 are consisting of steel which the carbon content is more than 0.45 mass% and less than 0.75 mass%. Additionally, the hub race 2, the inner race 3 and the outer race 4 are fabricated by performing a cold forging operation after giving softening and annealing to the cylindrical raw material which consists of the above steel. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
