BEARING DEVICE FOR DRIVING WHEELS

摘要

Provided is a bearing device for driving wheels, the bearing device improving workability during disassembly and assembly, and having improved durability as well. In the bearing device for driving wheels, an internal ring (5) is fixed to a hub ring (1) by a caulking part (13) formed by plastic-deforming an end of a small-diameter step part (1b) outward in the diameter direction; an external joint member (14) of a constant speed universal joint (3) integrally includes a shoulder part (19) and a cylindrical axis part (20) that extends from the shoulder part (19) in the axis direction and is provided with a female screw (20a); and face splines (19a) and (13a) are formed on end surfaces of the shoulder part (19) and the caulking part (13) respectively. Both of the face splines (19a) and (13a) are supported in a pressing manner by a fastening bolt (21) screwed so as to be fixed to the female screw (20a) of the axis (20) while abutting an end face of an outer side of the hub ring (1), the compressing residual stress is given to surfaces of both of the face splines (19a) and (13a) by the surface reform stress caused by shot peening, and the surface hardness is set at more than or equal to 300Hv.