A bearing unit having a stationary radially outer ring, a radially inner ring, rotatable with respect to a rotation axis (X) and steadily connected to a rotating shaft, a row of rolling bodies interposed between the radially outer ring and the radially inner ring, a casing, inside which the rings of the bearing unit are housed, a sealing device, and a protection disk. The protection disk may be mounted in an axially external position to the sealing device and fixed to the radially inner ring. Additionally, the protection disk may have a shaped metallic screen, and an elastomer coating over-molded on part of the screen. The protection disk may further be in contact with an axially external surface of the radially outer ring through the elastomer coating, which is provided with two lips, a first lip, non-contacting or contacting and radially external, and a second lip, contacting and radially internal.