Rolling device employing lubricating grease composition and electric power steering apparatus employing the rolling device

Abstract

A rolling device employing a lubricating grease composition containing a thickener which is a mixture of (a) one or more diurea compounds made from one or more primary amines and a diisocyanate; (b) at least one fatty acid metal salt; (c) at least one amide compound selected from the group consisting of aliphatic amides and bisamides, where the proportions of (a), (b) and (c) satisfy the relationship: a/(b+c)=0.2−10 provided that (1) the proportion of ingredient (a) is 1-10, (2) the proportion of ingredient (b) is 0.5-2.5, and (3) the proportion of ingredient (c) is 0.5-2.5, and the amount of the thickener is 2 to 30% by weight, based on the lubricating grease composition; (d) a base oil which is a lube base oil having a pour point of −36 to −67.7° C. that includes a synthetic hydrocarbon oil as the main component; and (e) 1-7% by weight of an additive mixture containing an organomolybdenum complex, an organozinc compound of a dithiocarbamic acid, and an organozinc compound of dithiophosphoric acid.