Abstract:
This invention relates to grease for roller bearings which contains poly- alpha -olefin synthetic oil or diphenylether synthetic oil, urea thickening agent, and organic antimony compound or organic molybdenum compound; and a roller bearing in which this grease is sealed. The organic antimony compound or organic molybdenum compound reacts with the rolling surfaces of the inner and outer races and the surfaces of rolling elements in the bearing to form compound films which contribute to the reduction of the tangential force, and to prevent the generation of an excessively large tangential force during the high-speed rotation of a rotary part. This enables the lifetime of a roller bearing, which is used, especially, under severe conditions, to be prolonged.