Patent ID: 7044563

Claim:
A wheel supporting roller bearing unit comprising: a hub including a mounting flange on its outer circumference, said mounting flange having a plurality of mounting through holes; a plurality of studs respectively press-fitted in the mounting through holes, each stud having a flanged portion at its root end portion and having a threaded leading end portion, in such manner that a disk brake rotor superposed over one side face of said mounting flange can be jointed and fixed by threadedly engaging the threaded leading end portions of the studs with nuts respectively, wherein said mounting flange has a portion on which said rotor is superposed, the portion is close to the outer circumference of said one side face and reaches the outer circumference edge of said mounting flange, and the portion includes a taper face extending throughout the circumference of said mounting flange, wherein said taper face is inclined in such a direction prior to said individual studs being press-fitted and fixed in said individual mounting holes that the taper face tapers away from or close to said rotor, and wherein the inner circumference edge of said taper face exists between a circumscribed circle and an inscribed circle of said individual mounting holes.