Swivel bearing unit

A swivel bearing unit, comprising:

• a radially outer ring configured to be stationary during use of the swivel bearing unit;
• a radially inner ring configured to rotate during use of the swivel bearing unit, with respect to a rotation axis (X), the radially inner ring configured to be fixed to a rotating shaft for rotation therewith;
• a double row of rolling bodies interposed between the radially outer ring and the radially inner ring;
• a casing for housing the radially outer ring and the radially inner ring;
• a sealing device, comprising an elastomer seal co-molded onto a shaped metal screen fixed to the casing;
• wherein:
• the elastomer seal comprises a first radial lip, which extends in a radially internal inward direction from a joining edge of the first radial lip joined to the elastomer seal, and with a second radial lip, which also extends in a radially internal inward direction from a joining edge of the second radial lip joined to the elastomer seal and axially more external than the first radial lip in relation to the double row of rolling bodies;
• the first radial lip and the second radial lip each comprise a contacting edge configured to make sliding contact with a radially external surface of the radially inner ring;
• and
• the first radial lip comprises a thickness (SP1) greater than a thickness (SP2) of the second radial lip;
• wherein a radial component (L1) of a length of the first radial lip comprises a radial distance between a joining edge of the first radial lip joined to the elastomer seal and a radially inner and axially outer end of the contacting edge, and a radial component (L2) of a length of the second radial lip comprises a radial distance between a joining edge of the second radial lip joined to the elastomer seal and a radially inner and axially outer end of the contacting edge;
• and
• the radial component (L1) of the length of the first radial lip and the radial component (L2) of the length of the second radial lip are a function of a diameter (ϕ) of a radially outer surface of the radially inner ring and an angular misalignment in the direction of the rotation axis (X) between the casing and the radially inner ring;
• wherein an axial distance (H1) between the joining edge of the first radial lip and an axially inner wall of the elastomer seal is between about 0.2 mm and about 3 mm.

A swivel bearing unit, comprising:

• a radially outer ring configured to be stationary during use of the swivel bearing unit;
• a radially inner ring configured to rotate during use of the swivel bearing unit, with respect to a rotation axis (X), the radially inner ring configured to be fixed to a rotating shaft for rotation therewith;
• a double row of rolling bodies interposed between the radially outer ring and the radially inner ring;
• a casing for housing the radially outer ring and the radially inner ring;
• a sealing device, comprising an elastomer seal co-molded onto a shaped metal screen fixed to the casing;
• wherein:
• the elastomer seal comprises a first radial lip, which extends in a radially internal inward direction from a joining edge of the first radial lip joined to the elastomer seal, and with a second radial lip, which also extends in a radially internal inward direction from a joining edge of the second radial lip joined to the elastomer seal and axially more external than the first radial lip in relation to the double row of rolling bodies;
• the first radial lip and the second radial lip each comprise a contacting edge configured to make sliding contact with a radially external surface of the radially inner ring;
• and
• the first radial lip comprises a thickness (SP1) greater than a thickness (SP2) of the second radial lip;
• wherein a radial component (L1) of a length of the first radial lip comprises a radial distance between a joining edge of the first radial lip joined to the elastomer seal and a radially inner and axially outer end of the contacting edge, and a radial component (L2) of a length of the second radial lip comprises a radial distance between a joining edge of the second radial lip joined to the elastomer seal and a radially inner and axially outer end of the contacting edge;
• and
• the radial component (L1) of the length of the first radial lip and the radial component (L2) of the length of the second radial lip are a function of a diameter (ϕ) of a radially outer surface of the radially inner ring and an angular misalignment in the direction of the rotation axis (X) between the casing and the radially inner ring;
• wherein a first angle (β) that each radial lip forms with the direction of the rotation axis (X) is between about 45° and about 75° and a second angle (α) that each contacting edge of the corresponding radial lips forms with the direction of the rotation axis (X) is between about 35° and about 65°.