| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a wheel bearing device and a manufacturing method therefor which can attain the reduction of the manufacturing cost while attaining the reduction of weight. <P>SOLUTION: The wheel bearing device includes a shaft member 1 with flanges, provided with a shaft portion 10 to which a rolling bearing 41 is assembled, a fitting shaft portion 30 that is formed on one-end side of the shaft portion 10 and fitted to a center hole of a wheel, and a plurality of flange portions 21 which extend radially to outward on an outer peripheral surface positioned between the shaft portion 10 and the fitting shaft portion 30 and each of which has a through bolt holes 24 in which a hub-bolt 27 for fastening the wheel is arranged. Each flange portion 21 is formed by side extrusion when a forged recess 33 is formed at a center of an end surface of the fitting shaft portion 30 by cold-forging. An edge portion 21e of a cross-sectional shaft taken perpendicularly to a longitudinal direction of each flange portion 21 is formed in a round-chamfered shape. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
