Sealing assembly for rolling bearings, in particular for a hub bearing unit of vehicles and associated hub bearing unit

A hub bearing unit for vehicles, comprising an outer stationary ring, an inner rotating ring, rotating about a common relative rotation axis (A) of the inner and outer rings, a plurality of rolling bodies interposed between the inner and outer rings and accommodated in an annular space radially delimited between the inner and outer rings, and at least one sealing assembly arranged to close the annular space accommodating the rolling bodies, having a first annular rigid shield designed to be supported by the first ring and a second annular rigid shield designed to be supported by the second ring;

• wherein:
• i) the second annular rigid shield is L-shaped in radial section and provides a radially outer sleeve-shaped journaling portion and a flange portion that extends cantilevered radially inwards starting from a first end of the journaling portion facing towards the side opposite the first annular shield;
• the second annular rigid shield integrally and radially carrying on the inside a first annular sealing element made of elastomeric material;
• and wherein:
• ii) the first annular rigid shield is shaped in radial section like a C having concavity facing towards the second annular rigid shield and includes a first radially inner sleeve portion defining a journaling portion of the first rigid shield, a flange portion that extends cantilevered radially outwards starting from a first end of the first sleeve portion facing towards the side opposite the second annular rigid shield, and a second sleeve portion which extends axially cantilevered from the flange portion of the first shield on the same side of the first sleeve portion of the first rigid shield;
• the first and second sleeve portion of the first rigid shield being radially facing to one another and being coaxial in relation to a common symmetry axis (A) of the first and second rigid shield;
• iii) the first annular sealing element having a first, elastically deformable, annular lip that extends axially cantilevered from the flange portion of the second rigid shield and towards the first rigid shield to be radially interposed between the first and the second sleeve portion of the first rigid shield;
• and a second annular lip, elastically deformable, which is arranged radially on the inside of the first annular lip and extends axially and radially to cooperate in contact with the first rigid shield, with which it defines a sliding seal;
• iv) the first annular lip is shaped to delimit radially outwardly a first annular channel facing towards a free end edge of the second sleeve portion of the first rigid shield, opposite the flange portion of the first rigid shield;
• wherein
• v) the first annular sealing element provides a third annular lip, elastically deformable, which extends radially and axially cantilevered from the journaling portion of the second rigid shield and towards the flange portion of the first rigid shield, to be interposed between the journaling portion of the second rigid shield and the second sleeve portion of the first rigid shield, obliquely to the flange portion of the first rigid shield;
• vi) the third annular lip designed to selectively assume:
• a first configuration, non-deformed, in which it does not contact a radially outer lateral surface of the second sleeve portion of the first rigid shield, defining therewith a sufficiently small radial clearance to form a first labyrinth seal, radially directed;
• and a second configuration, deformed, in which, in response to the application of a force external to the sealing assembly, it contacts the radially outer lateral surface of the second sleeve portion of the first rigid shield, forming a sliding seal thereon.