Abstract: A rolling bearing includes an outer ring, a plurality of rolling elements, a cage configured to rollably hold the plurality of rolling elements, and a shield. An inner peripheral surface of at least one axial end portion of the outer ring is provided with a large-diameter part, which has a diameter larger than an inner diameter of the outer ring, opens outward in an axial direction, and has an axial width greater than an axial width of the shield. An outer shape surface of the shield is configured by a plurality of circular arcs having a same central angle and equidistantly arranged on a circumference and a plurality of chords connecting adjacent circular arcs each other. The shield is press-fitted and fixed to the large-diameter part.

Abstract: A rolling bearing includes an outer ring, a plurality of rolling elements, a cage configured to rollably hold the plurality of rolling elements, and a shield. An inner peripheral surface of at least one axial end portion of the outer ring is provided with a large-diameter part, which has a diameter larger than an inner diameter of the outer ring, opens outward in an axial direction, and has an axial width greater than an axial width of the shield. An outer shape surface of the shield is configured by a plurality of circular arcs having a same central angle and equidistantly arranged on a circumference and a plurality of chords connecting adjacent circular arcs each other. The shield is press-fitted and fixed to the large-diameter part.

Abstract: A grease composition for EV/HEV driving motor bearing, containing a diurea thickener of the following formula (A): wherein R1, R2 and R3 are defined, with the ratio of the number of moles of the straight-chain or branched alkyl group having 16 to 20 carbon atoms to the total number of moles of the cyclohexyl group and the straight-chain or branched alkyl group having 16 to 20 carbon atoms, expressed as [((the number of alkyl group)/(the number of cyclohexyl group+the number of alkyl group))×100] being 60 to 80%, and a base oil which has a kinematic viscosity at 40° C. of 15 to 50 mm2/s and includes a trimethylolpropane ester oil in an amount of 80 mass % or more based on the total base oil mass. The grease composition can exhibit a long bearing lubrication life at high temperature and high speed, and satisfactory low-temperature flowability.

Abstract: A tapered roller bearing improves durability during a state of insufficient lubrication by sufficiently lengthening the time until rotation becomes impossible due to seizure. Oil retaining concave sections, recessed outward in the radial direction, are formed in portions on the inner circumferential surface of a large-diameter rim section of the retainer whose phase in the circumferential direction coincides with the pockets. A portion of the bottom surface of each of the oil retaining concave sections, open to the inside surface of the pocket, face a concave section formed in an end surface on the large-diameter side of tapered roller that is held inside the pocket. When lubrication becomes insufficient, oil remaining in the concave sections is effectively used for lubricating areas of sliding contact between the end surfaces on the large-diameter side and the inside surface in the axial direction of a large-diameter side flange section.

Abstract: A grease composition for EV/HEV driving motor bearing, containing a diurea thickener of the following formula (A): wherein R1, R2 and R3 are defined, with the ratio of the number of moles of the straight-chain or branched alkyl group having 16 to 20 carbon atoms to the total number of moles of the cyclohexyl group and the straight-chain or branched alkyl group having 16 to 20 carbon atoms, expressed as [((the number of alkyl group)/(the number of cyclohexyl group+the number of alkyl group))×100] being 60 to 80%, and a base oil which has a kinematic viscosity at 40° C. of 15 to 50 mm2/s and includes a trimethylolpropane ester oil in an amount of 80 mass % or more based on the total base oil mass. The grease composition can exhibit a long bearing lubrication life at high temperature and high speed, and satisfactory low-temperature flowability.

Abstract: A tapered roller bearing improves durability during a state of insufficient lubrication by sufficiently lengthening the time until rotation becomes impossible due to seizure. Oil retaining concave sections, recessed outward in the radial direction, are formed in portions on the inner circumferential surface of a large-diameter rim section of the retainer whose phase in the circumferential direction coincides with the pockets. A portion of the bottom surface of each of the oil retaining concave sections, open to the inside surface of the pocket, face a concave section formed in an end surface on the large-diameter side of tapered roller that is held inside the pocket. When lubrication becomes insufficient, oil remaining in the concave sections is effectively used for lubricating areas of sliding contact between the end surfaces on the large-diameter side and the inside surface in the axial direction of a large-diameter side flange section.