Abstract: A grease composition is disclosed, wherein a metallic soap-base thickener containing a long-fiber material having a major axis part length of at least 3 ?m is blended with a base oil obtained by mixing a lubricating oil having a polar group within the molecule structure and a non-polar lubricating oil, which can improve the initial sound (cage sound) of bearing at the starting of operation in a low-temperature environment and is effective on the reduction of fretting damage (abrasion) or torque, and also a rolling bearing and a linear acting apparatus each obtained by packing the grease composition are disclosed, which exhibit excellent low-temperature acoustic property and are reduced in the fretting damage (abrasion) or torque.

Abstract: To provide a grease composition for auxiliary machinery of automobile electrical component containing an aromatic ester oil-containing base oil having a specific diurea compound as a thickener blended therewith and a rolling bearing having the foregoing grease composition packed therein. The foregoing grease composition and rolling bearing do not generate abnormal noises even at an extremely low temperature of ?40° C., have excellent seizure resistance even under a high temperature closed to 180° C., have excellent rust preventing performance, and are suitable especially for electrical parts and auxiliary machineries of engines, etc.

Abstract: A rolling bearing to exhibit outstanding initial (cage) acoustic characteristics at the start of operation under a low temperature atmosphere, suppress fretting damages (abrasions) and reduce bearing torque by making the radius of curvature of the cross-sectional shape of the inner raceway and the radius of curvature of the cross-sectional shape of the outer raceway equal to 51.0% to smaller than 60.0% of the diameter of the rolling element, and packing a grease composition comprising a base oil that is a mixture of a lubricant containing a polar group in its molecular structure and a non-polar lubricant and a metallic soap-based thickener containing a long-fiber material with a major axis part length of at least 3 &mgr;m.

Abstract: A rolling bearing to exhibit outstanding initial (cage) acoustic characteristics at the start of operation under a low temperature atmosphere, suppress fretting damages (abrasions) and reduce bearing torque by making the radius of curvature of the cross-sectional shape of the inner raceway and the radius of curvature of the cross-sectional shape of the outer raceway equal to 51.0% to smaller than 60.0% of the diameter of the rolling element, and packing a grease composition comprising a base oil that is a mixture of a lubricant containing a polar group in its molecular structure and a non-polar lubricant and a metallic soap-based thickener containing a long-fiber material with a major axis part length of at least 3 &mgr;m.

Abstract: A grease composition is disclosed, wherein a metallic soap-base thickener containing a long-fiber material having a major axis part length of at least 3 &mgr;m is blended with a base oil obtained by mixing a lubricating oil having a polar group within the molecule structure and a non-polar lubricating oil, which can improve the initial sound (cage sound) of bearing at the starting of operation in a low-temperature environment and is effective on the reduction of fretting damage (abrasion) or torque, and also a rolling bearing and a linear acting apparatus each obtained by packing the grease composition are disclosed, which exhibit excellent low-temperature acoustic property and are reduced in the fretting damage (abrasion) or torque.