Search International and National Patent Collections
|1. (WO2013115319) BEARING DEVICE FOR WHEEL|
|Title:||BEARING DEVICE FOR WHEEL|
[Problem] To provide a bearing device for a wheel, the bearing device having increased durability obtained by reducing torque applied to a spline section. [Solution] A bearing device for a wheel has a second or third generation structure configured so that a gear member (24) which selectively switches between four-wheel drive and two-wheel drive is affixed to an inner member (1) which comprises a hub ring (4) and inner rings (5, 7) fitted to the hub ring (4). The gear member (24), which is ring-shaped and hardened, is mounted to an end of the small-diameter stepped section (4b) of the hub ring (4). The gear member (24) has a gear section (24a) formed on the outer periphery thereof, and has a spline section (24b) formed on the inner periphery thereof, the spline section (24b) meshing with a hub spline section (25) formed on the outer peripheral surface of the small-diameter stepped section (4b). The contact surface of the gear member (24) which makes contact with the inner ring (7) is ground to surface roughness (Ra) of 1.6 or less. The inner ring (7) is affixed in the axial direction with a predetermined bearing preload applied by a staked section (4c) through the gear member (24).