SWIVEL BEARING UNIT

A swivel bearing unit (30) having:a stationary radially outer ring (31 );- a radially inner ring (33), which is rotatable with respect to a rotation axis (X) and stably connected to a rotating shaft (45);a double row of rolling members (32) interposed between the radially outer ring (31 ) and the radially inner ring (33);a casing (40), inside which the rings of the bearing unit are housed;a sealing device (50), comprising an elastomer seal (52) comoulded onto a shaped metal screen (51) stably anchored to the housing (40), whereinthe elastomer seal (52) is provided with a first radial lip (53), which is radially internal and contacting, and with a second radial lip (54), which is also radially internal and contacting and axially more external than the first radial lip (53) in relation to the double row of rolling bodies (32);both the first radial lip (53) and the second radial lip (54) make sliding contact by means of respective contacting edges (53b, 54b) with a radially external surface (33') of the radially inner ring (33);the first radial lip (53) has a thickness (SP1) greater than a thickness (SP2) of the second radial lip (54).