Abstract: A roller contact bearing unit, in particular for the hub of a vehicle wheel, including a radially outer rotating race (10), a radially inner stationary race (11), a sealing device (16) between the races (10, 11) and a device for measuring the rotation speed of the outer race (10). The measuring device includes an encoder wheel (13) in the form of a radially oriented annular disc made of plastic or rubber magnetized material, and an annular insert made of non-magnetic metal (14) which is suitably shaped to form: a constraining means (14a) for fixing the insert (14) onto the outer race of the bearing unit, an axial abutting means (14b) suitable for abutting against a lateral surface (10b) of the outer race (10), an annular seat (14c) for housing and externally enclosing the encoder wheel (13), and a support means (14d) for a rubber element (15) which forms a sealing covering (15b) suitable for sliding against a surface (16) which forms part of a non-rotating element (11) of the bearing unit.

Abstract: A rolling contact bearing has a rotating unit to be integrally assembled to a rotating race (11) of the bearing, comprised of a first metallic annular insert (19) which forms a substantially disc-shaped radial wall (22) and a non-rotating unit to be integrally assembled to the non-rotating race (10) of the bearing, comprised of a second metallic annular insert (15) which has a sealing covering (14) with at least one sealing lip (18) suitable for sliding against the axially inner side of the disc-shaped wall (22); the rotating unit forms at least one substantially radial rotating surface (25) of a given minimum diameter (DR) and the non-rotating unit forms at least one substantially radial non-rotating surface (25) with a maximum diameter (DS) lesser than the minimum diameter, where the units are reciprocally positioned in such a way that the rotating surface (25) is facing the non-rotating surface (23a) from an inner axial position to form an axial stop for the non-rotating surface (23a), so as to provisional