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: A ball bearing is described, which comprises an outer ring having on its inner periphery an outer raceway, an inner ring having on its outer periphery an inner raceway, plural balls rotatably disposed between the outer raceway and the inner raceway, a cage holding the plural balls in a freely rotatable manner, and a grease packed in a space between the outer raceway and the inner raceway, wherein the inner peripheral surface of each pocket of the cage contains a spherical part consisting of a spherical concave surface whose radius of curvature is slightly larger than that of each ball and a curved part which has the radius of curvature being larger than that of the spherical part and is smoothly continuous from the end of the spherical part toward the end thereof on the opening side of the pocket.

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 ball bearing is described, which comprises an outer ring having on its inner periphery an outer raceway, an inner ring having on its outer periphery an inner raceway, plural balls rotatably disposed between the outer raceway and the inner raceway, a cage holding the plural balls in a freely rotatable manner, and a grease packed in a space between the outer raceway and the inner raceway, wherein the inner peripheral surface of each pocket of the cage contains a spherical part consisting of a spherical concave surface whose radius of curvature is slightly larger than that of each ball and a curved part which has the radius of curvature being larger than that of the spherical part and is smoothly continuous from the end of the spherical part toward the end thereof on the opening side of the pocket.

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: An improved lubricating grease composition is herein disclosed, which comprises a base oil and a thickening agent, wherein the base oil comprises 50 to 100% by weight of a carbonate ester compound represented by the following general formula (I): R1O—CO—OR2  (I) wherein R1 and R2 each independently represents a saturated or unsaturated, linear or branched alkyl group having 6 to 30 carbon atoms, on the basis of the total weight of the base oil. The lubricating grease composition shows remarkably improved acoustic life and an improved frictional coefficient, as compared with those observed for conventional grease compositions.

Abstract: A grease composition for rolling bearing comprising a metal soap-based thickening agent containing a long fiber-like material having a major axis length of at least 3 &mgr;m incorporated in a base oil comprising a lubricant having a polar group in its molecular structure and a non-polar lubricant blended in combination.

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.

Abstract: An improved lubricating grease composition is herein disclosed, which comprises a base oil and a thickening agent, wherein the base oil comprises 50 to 100% by weight of a carbonate ester compound represented by the following general formula (I): 1

Abstract: An improved lubricating grease composition is herein disclosed, which comprises a base oil and a thickening agent, wherein the base oil comprises 50 to 100% by weight of a carbonate ester compound represented by the following general formula (I): R1O—CO—OR2  (I) wherein R1 and R2 each independently represents a saturated or unsaturated, linear or branched alkyl group having 6 to 30 carbon atoms, on the basis of the total weight of the base oil. The lubricating grease composition shows remarkably improved acoustic life and an improved frictional coefficient, as compared with those observed for conventional grease compositions.

Abstract: A cage for a rolling bearing; the cage is obtained by molding a resin composition comprising 100 parts by weight of a heat-resistant and oil-resistant resin and from 5 to 100 parts by weight of a polyolefin and immersing the resulting molded article in a lubricating oil. Also is disclosed is a rolling bearing with the cage fitted therein and having been subjected to oil plating.

Abstract: A grease composition for rolling bearing comprising a metal soap-based thickening agent containing a long fiber-like material having a major axis length of at least 3 ?m incorporated in a base oil comprising a lubricant having a polar group in its molecular structure and a non-polar lubricant blended in combination.