| abstract |
The present invention provides a hub bearing, made of carbon steel for machine structural use, which has a long life even in a strict lubricating condition by improving the resistance to peeling starting from the surface. A grease for the hub bearing contains a base oil, a thickener, and an organozinc compound which is at least one compound selected from dithiozinc carbamate and dithiozinc phosphate. The base oil is a mineral oil or a mixed oil of a mineral oil and a synthetic hydrocarbon oil. The thickener is a urea compound shown by the following formula (1) and is contained at 1 to 40 mass % for the entire grease. The grease for the hub bearing is enclosed in the hub bearing. (In the formula (1), R 2 indicates an aromatic hydrocarbon group having 6 to 15 carbon atoms, and R 1 and R 3 indicate at least one hydrocarbon group selected from an alicyclic hydrocarbon group and an aromatic hydrocarbon group. |