Grease composition, grease-enclosed bearing, and one-way clutch

摘要

The present invention provides a grease composition capable of effectively preventing a rolling surface from having hydrogen brittleness-caused peeling, a grease-enclosed bearing in which the grease composition is enclosed, and a one-way clutch in which the grease composition is enclosed at a sliding portion. The grease composition contains a base grease consisting of a base oil and a thickener and an additive added to the base grease. The grease composition is capable of preventing hydrogen brittleness-caused peeling from occurring on a frictionally worn surface of a bearing portion containing an iron-based metal material or a newly generated surface consisting of the iron-based metal material exposed owing to wear. The additive contains at least one aluminum-based additive selected from among an aluminum powder and inorganic aluminum compounds. The mixing ratio of the aluminum-based additive to 100 parts by weight of the base grease is set to 0.05 to 10 parts by weight.

主权项

1. A grease composition for preventing a frictionally worn surface of a bearing portion containing an iron-based metal material or a newly generated surface consisting of the iron-based metal material exposed owing to wear from being peeled by hydrogen brittleness,
said grease composition comprising a base grease which consists of a base oil and a thickener; and an additive added to said base grease, wherein said additive contains an antioxidant and aluminum sulfate, wherein the mixing ratio of said aluminum sulfate to 100 parts by weight of said base grease is set to 0.1 to 5 parts by weight, and wherein said thickener comprises a diurea-based compound represented by the formula (1) R1 and R3 in the formula (1) indicate hydrocarbon radicals having carbon atoms of 6 to 20; R1 and R3 are identical to or different from each other; and R2 indicates an aromatic hydrocarbon radical having carbon atoms of 6 to 15.