GREASE COMPOSITION FOR CONSTANT VELOCITY JOINTS AND CONSTANT VELOCITY JOINTS PRELUBRICATED WITH THE SAME

摘要

The present invention provides a grease composition for use in constant velocity joints, which comprises the following components (a) to (g) and a constant velocity joint comprising the grease composition sealed or encapsulated therein:
(a) a base oil;
(b) a diurea thickener represented by the following general formula:
€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒR 1 NH-CO-NH-C 6 H 4 -p-CH 2 -C 6 H 4 -p-NH-CO-NHR 2
wherein R 1 and R 2 each independently represents an alkyl group having 8 to 20 carbon atoms, an aryl group having 6 to 12 carbon atoms or a cycloalkyl group having 6 to 12 carbon atoms;
(c) a molybdenum dialkyl dithiocarbamate insoluble in the base oil;
(d) a molybdenum dialkyl dithiocarbamate soluble in the base oil;
(e) molybdenum disulfide;
(f) at least one member selected from the group consisting of calcium phenate and calcium sulfonate; and
(g) a sulfur-containing extreme-pressure agent free of phosphorus. The grease composition can efficiently prevent a temperature rise of a constant velocity joint and can impart excellent durability to the joint.