Patent ID: 7491683

Claim:
A grease composition for a rolling bearing, comprising: a lubricating base oil comprising a diphenyl ether synthetic oil; a diurea thickening agent; and a bismuth dithiocarbamate represented by the following general formula (1): in which R 1 and R 2 are same as or different from each other and each individually represents a hydrogen atom, an alkyl group comprising 1 to 12 carbon atoms, or an aryl group comprising 6 to 8 carbon atoms, wherein the bismuth dithiocarbamate comprises a range of 0.5% to 5% by weight based on an entire weight of the lubricating base oil and the thickening agent, such that a sound characteristic of the rolling bearing is not affected by said bismuth dithiocarbamate, and a load-carrying capacity is improved by reacting said bismuth dithiocarbamate with one of a surface of a raceway of inner and outer rings of said rolling bearing and a surface of a rolling element of the rolling bearing to thereby form a surface film of one of bismuth oxide and bismuth sulfide.