Gear-driven bearing unit

A gear-driven bearing unit comprising a housing, a drive gear and a rolling element bearing, the rolling element bearing comprising:

• an outer member provided with teeth for meshing with teeth of the drive gear, an inner member and one or more rows of rolling elements disposed between the inner and outer members, whereby at one axial side of the gear-driven bearing unit
• a first radial gap exists between a radially inner surface of the outer member and a radially outer surface of the inner member;
• and
• a second radial gap exists between a radially outer surface of the outer member and a radially inner surface of the housing,
• the gear-driven bearing unit being at least partly filled with a grease lubricant, which is retained within the gear-driven bearing unit by a first seal provided in the first radial gap and by a second seal provided in the second radial gap,
• wherein:
• the radially inner surface of the housing comprises a first axially extending surface, a radially extending groove, and a finger having a rectangular-shaped cross-section, the first axially extending surface radially overlaps the one or more rows of rolling elements, the radially extending groove extends radially outwardly from an axial end of the first axially extending surface and is axially delimited by the axial end of the first axially extending surface and the finger, the finger located on an opposite side of the radially extending groove from the axially extending surface such that the finger extends radially inwardly with respect to a bottom surface of the radially extending groove and has a minimum radius greater than a radius of the first axially extending surface,
• one of the first and second seals comprises a first radial lip and a second radial lip that bear against a radially oriented counterface, the first seal comprises a first mounting part that has a rectangular cross-section and is inserted in a groove located in the radially outer surface of the inner member, the second seal comprises a second mounting part that has a U-shaped cross-section, the second mounting part being configured to receive the finger therein such that a portion of the second mounting part is located in the radially extending groove and such that the finger is contacted on each axial side by the second mounting part;
• and in that
• the grease lubricant comprises a calcium-based thickener or comprises calcium salt additives;
• the teeth of the drive gear are made of a bearing-grade steel;
• and in that
• the teeth on the outer member are made of a bearing-grade steel that has been subjected to a hardening treatment that diffuses nitrogen into a surface of the teeth.