The invention has an object of providing grease reduced in an amount of the flying grease and an amount of the outgas, and superior in low-temperature characteristic, an antifriction bearing using the grease, an antifriction bearing device, and an information recording/reproducing device. A grease includes a base oil, and a thickener, the base oil includes mineral oil and poly-α-olefin, the poly-α-olefin is higher in mass than the mineral oil, the poly-α-olefin includes poly-α-olefin higher in kinetic viscosity than the mineral oil, the kinetic viscosity of the base oil at 40° C. is in a range of 40 through 90 mm.sup.2/s, and worked penetration is in a range of 200 through 250. Further, an antifriction bearing, an antifriction bearing device, and an information recording/reproducing device use the grease.

A cage for a bearing, including: a first annular segment; a second annular segment located radially inwardly of the first annular segment; a vane connected to the first annular segment and to the second annular segment and including a first axial end facing at least partly in a first axial direction parallel to an axis of rotation of the cage and a second axial end facing at least partly in a second axial direction, opposite the first axial direction, the second axial end off-set from the first axial end in a circumferential direction around the axis of rotation; and a curved surface connected to the first annular segment and the second annular segment and arranged to retain a ball of the bearing. The first annular segment, the second annular segment, the vane, and the curved segment define a channel passing through the cage.

There is provided a ball bearing having a cage and balls held in the cage, the balls arranged one behind the other at a distance from one another in a circumferential direction about an axis of rotation of the ball bearing. The cage assembled from at least two cage parts joined to one another in a bonded manner and completely enclose the balls in a circumferential surface extending around the axis of rotation. A first cage part designed as a snap cage having axial webs projecting in the direction of the axis of rotation from a closed base ring and form ball pockets therebetween them, the first cage part encloses the balls along their outer circumference by more than 180°, holds the balls positively while forming an undercut and limits displacement of the balls within the circumferential surface in the direction of the at least one other second cage part.

A holder has a protrusion which protrudes from a side surface at a side opposite in an axial direction with respect to a rolling element held in a pocket toward the side opposite in the axial direction. An oil supply hole which penetrates through the holder from the side surface to a surface at a side of the rolling element in the axial direction is formed in the holder. When the holder rotates, the protrusion guides oil into the oil supply hole, and the oil is introduced from the side surface of the holder to the surface on the side of the rolling element.

A cage of an angular ball bearing includes, with respect to a plurality of balls arranged between an outer member and an inner member, an annular portion positioned on one side in an axial direction of the angular ball bearing, and a plurality of pillar portions provided to extend from the annular portion to the other side in the axial direction. The pillar portions include a first flat surface portion contactable with the balls on one side in a circumferential direction of the angular ball bearing, and a second flat surface portion contactable with the balls on the other side in the circumferential direction and parallel to the first flat surface portion.

There is provided a ball bearing having a cage and balls held in the cage, the balls arranged one behind the other at a distance from one another in a circumferential direction about an axis of rotation of the ball bearing. The cage assembled from at least two cage parts joined to one another in a bonded manner and completely enclose the balls in a circumferential surface extending around the axis of rotation. A first cage part designed as a snap cage having axial webs projecting in the direction of the axis of rotation from a closed base ring and form ball pockets therebetween them, the first cage part encloses the balls along their outer circumference by more than 180° , holds the balls positively while forming an undercut and limits displacement of the balls within the circumferential surface in the direction of the at least one other second cage part.

A bearing cage for a rotor bearing of a turbomolecular pump. The bearing cage includes a plurality of bearing pockets each of which, in use, houses a bearing ball such that the bearing ball operably engages an inner race and an outer race of the rotor bearing. Each bearing pocket of the bearing cage has a primary chamber for housing the bearing ball and each bearing pocket further includes a sump.

The present invention proposes a deep groove ball bearing, having an outer ring, an inner ring, spherical rollers located between the inner ring and outer ring, and a cage for holding the spherical rollers. In an axial direction, the inner ring has a first inner ring shoulder at a first side, and a second inner ring shoulder at a second side opposite the first side; and a first inner ring shoulder diameter of the first inner ring shoulder is configured to be larger than a second inner ring shoulder diameter of the second inner ring shoulder. The present invention further proposes a differential including the deep groove ball bearing.

The resin injection gate is disposed at the pillar part. When the bearing cage is divided into first and second regions by an imaginary line connecting the resin injection gate and a weld to be formed at a position radially facing the resin injection gate, a resin reservoir that can store therein the melted resin is formed at the pillar part in only one of the regions. A circumferential distance between the resin reservoir and the weld is smaller than a circumferential distance between the resin reservoir and the resin injection gate. A cross-sectional area of a communicating part of the resin reservoir, which is configured to communicate with the pillar part, is equal to or less than a quarter of a cross-sectional area of the resin injection gate.

A holder has a protrusion which protrudes from a side surface at a side opposite in an axial direction with respect to a rolling element held in a pocket toward the side opposite in the axial direction. An oil supply hole which penetrates through the holder from the side surface to a surface at a side of the rolling element in the axial direction is formed in the holder. When the holder rotates, the protrusion guides oil into the oil supply hole, and the oil is introduced from the side surface of the holder to the surface on the side of the rolling element.