Abstract: Radially outer ring of a bearing unit for a hub-wheel assembly for motor vehicles, the radially outer ring being provided with: a flange portion having a plurality of axial fixing holes that connect an element of the motor vehicle wheel to the radially outer ring, an almost cylindrical portion which with part of its radially internal surfaces defines raceways for rows of rolling bodies of the bearing unit, an axially internal or axially external surface of the flange portion and a radially external surface of the cylindrical portion connected to each other by a first portion of toroidal surface (St1) and of a second portion of toroidal surface (St2) defined by corresponding first radius (R1) and second radius (R2), a truncated cone surface (Stc) defined by an angle (a) formed with a rotation axis (X) of the radially outer ring is interposed between the first portion of toroidal surface (St1) and the second portion of toroidal surface (St2).

Abstract: A sealing device for a hub/wheel assembly with a roller bearing, the sealing device comprising a guard, made of plastic, which is coupled to an outer ring of the bearing so as to seal off the bearing, and which has a cylindrical mounting wall having an outer lateral surface coupled to an inner lateral surface of a collar of the outer ring. The sealing device includes a snap-engagement tooth for engaging with the collar made along the outer lateral surface so that the snap-engagement tooth snap-fits in a contoured annular groove made along the collar about the axis and an annular gasket made of thermoplastic elastomer being co-injection-molded inside a gripping seat made in the cylindrical mounting wall on the same side as the snap-engagement tooth, substantially at a corner defined between the cylindrical mounting wall and an annular reading wall transverse to the cylindrical mounting wall.