BEARING DEVICE FOR WHEEL

摘要

A bearing device for a wheel, where anti-creep properties of an inner ring fitting surface of a hub ring is increased and durability of the hub ring and an inner ring fixed by staking to the hub ring is improved. In the bearing device, the inner ring (5) has a large flange section (5b) on the large diameter side of an inner rolling surface (5a), and the inner ring (5) is press-fitted on a small-diameter step section (1b) of the hub ring (1) and fixed by staking section (8). An annular recess (13) is formed in an end of the small-diameter step section (1b), and the depth (b) of the recess (13) is set at not more than 5 mm from an end (5d) of the inner ring (5). A predetermined hardened layer (12) is formed by induction hardening in a region from the base of a wheel installation flange (3) to the small-diameter step section (1b). The end position (P) on the inner side of the hardened layer (12) is set in a range from an edge (P0) of a chamfered section (5e) of the inner ring (5) up to a position corresponding to the height (a) of the large flange section (5b). As a result, fretting wear on the fitting surface is suppressed to improve durability of the hub ring and deformation of the large flange section (5b) of the inner ring (5) caused by the staking is minimized.