| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a wheel bearing device reducing manufacturing cost, while reducing weight, and more stably mounting a brake rotor. <P>SOLUTION: This wheel bearing device includes a flanged shaft member 1 having a shaft portion 10, a fitting shaft portion 30 and flange portions 21. The flange portions 21 are formed by side extrusion when a forged recess is formed at an end face of a center portion of the fitting shaft portion 30 by cold forging. As for an outermost diameter shape of a side extrusion direction end portion of each of the flange portions 21, an outer diameterϕK at an end portion position on a side of a rotor support surface 22 constituted on the fitting shaft portion 30 to be a surface for supporting the brake rotor is formed to be larger than an outer diameterϕJ of an end portion position on a side of a bolt seat surface 21c constituted on an opposite side surface of the rotor support surface 22 to arrange a hub bolt 27 for fastening a wheel or have the same shape as the outer diameterϕJ. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
