Low friction sealing device and associated rolling bearing

A rolling bearing for a hub bearing unit or a railroad axle, the rolling bearing comprising:

• a stationary inner ring;
• a rotatable outer ring;
• a plurality of rolling elements housed in a radial annular space bounded between the inner ring and the outer ring to make the inner ring and the outer ring freely rotatable with respect to each other about a common axis of symmetry;
• and
• a sealing device configured to close at least one open axial end of the annular space and including a first annular shield angularly integral with the inner ring, a second annular shield angularly integral with the outer ring and rotating in use therewith, the first shield facing the second shield and being radially housed inside the second shield, a first elastomeric sealing element integral with the second shield and provided with at least one annular sealing lip sealingly engageable with a sliding surface of the first shield, and a second elastomeric sealing element integral with the first shield and arranged in a position facing a radially outer section of the first elastomeric sealing element, the radially outer section being continuously connected, or not, to the at least one annular sealing lip;
• wherein the second elastomeric sealing element and the radially outer section of the first elastomeric sealing element define between them an annular channel at least partially inclined with respect to the common axis of symmetry, having a direction of inclination forming a first acute angle with the axis of symmetry on the side of the second shield, the annular channel being bounded between a first lateral surface of the radially outer section of the first elastomeric sealing element defined by a conical surface with no relief and a second lateral surface, opposite to the first lateral surface, of the second elastomeric sealing element, facing and substantially parallel to the first lateral surface, and provided toward the first lateral surface with a plurality of annular steps configured to result in a plurality of localized variations of passage sections within the annular channel configured to produce turbulence in the annular channel as a result of rotation of the second shield about the common axis of symmetry, the steps being configured to direct any external contaminants that have penetrated into the annular channel against the first lateral surface such that the rotating first lateral surface guides the external contaminants out of the annular channel by centrifugal force and/or gravity.