To provide a bearing device for a driving wheel that can prevent generation of stick-slip noises, even if a predetermined axial force is loaded on an outer joint member and a large twist is generated in the outer joint member.

A constant-velocity universal joint 3 is coupled to a hub ring 1 through a torque transmitting means. The torque transmitting means is constituted with a fitting profile 22 where convex teeth 22a are formed on an outer circumferential surface of a shaft portion 20, and a fitting profile 24 where concave teeth 24a are formed on an inner circumferential surface of the hub ring 1. The convex teeth 22a and the concave teeth 24a that engage with each other are formed approximately in a trapezoidal cross-section having a negative pressure angle, and are formed with tooth surfaces having an inclined angle in the axial direction. A coupling means is constituted with a coupling ring 26 that is formed of a steel plate and is formed appropriately in an L-shaped cross-section. The coupling means includes a cylindrical portion 26a fitted onto an end portion of the non-quenched shaft portion 20 and formed with a plurality of projections 29 on the inner circumferential surface. The cylindrical portion 26a has a flange portion 26b, and a flange portion 26c inclined and outwardly extending in the radial direction at its ends. The flange portion 26c is elastically deformed to contact with the hub ring 1, and thereby providing a predetermined axial force on the shaft portion 20.