| 摘要 |
A bearing device for a wheel, in which the sealing ability and durability of a seal are enhanced to extend the life of a bearing. The bearing device for a wheel has the seal (8) mounted to an opening of an annular space formed between an outer member (5) and a hub ring (1'). An inner base (6b) of a wheel mounting flange (6) has a circular arc cross-sectional shape, and the seal (8) makes sliding contact with the base (6b). A step (15) is formed between an inner side surface (6d) and the base (6b) of the wheel mounting flange (6), and a corner of the step (15) is formed in a combined circular arc surface having curvature radii (Ra, Rb). An annular recess (13) is formed in the inner periphery at the outer end of the outer member (5). A substantially L-shaped labyrinth seal (14) is formed so as to face the corner of the step with a small gap therebetween. Because of the construction above, stress concentration in the hub ring (1') is relaxed and the seal (8) is prevented from being directly exposed to muddy water coming from the outside, and as a result, the sealing ability and durability of the seal (8) are enhanced. |
