GREASE FOR ENCAPSULATING IN BEARING

摘要

PROBLEM TO BE SOLVED: To obtain the subject grease retaining its high-temperature durability and having good lubricity cover the wide temperature range from low to high temperatures so as to prevent developing allophone when it is cold. SOLUTION: This grease is obtained by incorporating 5-20wt.% of a ureabased thickening agent in a base coil comprising a synthetic hydrocarbon oil and an ester-based synthetic oil expressed by the formula (R1 to R4 are each an alkyl group; (x) and (y) are each an integer satisfying the relationships : (x) >=2 and (y) >=2) and having such structure as to arrange at least 8 ester groups comb teeth-fashion on one side of the >=8 carbon atoms constituting the oil's chain molecule in the weight ratio of (0.65-0.75): (0.35-0.25). Besides, this grease may be incorporated with 0.1-10wt.% of a dithiophosphate such as zinc dithiophosphate as extreme pressure agent. This grease is applicable as a grease for encapsulating in a ball bearing designed to support a pulley for revolving belts through which rotary mechanical power is transmitted from an automotive engine, preventing development of allophone in engine start-up at low temperatures.