A bearing unit may be provided with at least one row of rolling bodies and at least one cage for retaining the rolling bodies. The at least one rolling cage may include a base rib; a plurality of fingers spaced circumferentially and extending at least from one side of the base rib; and a plurality of partially spherical cavities for holding the rolling bodies, each cavity being defined by the partially spherical concave surfaces of a pair of fingers of the plurality of fingers and of the base rib. The rolling bodies and the cages are in contact with each other via a plurality of protrusions formed on the partially spherical concave surfaces of the fingers and of the base rib. At least one lateral protrusion may be formed along the surface of each finger of the plurality of fingers of the retaining cage.

A ball bearing includes an inner ring; an outer ring placed outside of the inner ring; a plurality of rolling bodies intervening between the inner ring and the outer ring; and an annular cage including pockets rotatably holding the rolling bodies in a circumferential direction at intervals determining a rotation axis to be a center. The cage comprises a resin composition comprising a polyetherketone-based resin, graphite, and a carbon fiber. The resin composition comprises the polyetherketone-based resin in an amount of 60% by weight or more and 80% by weight or less, the graphite in an amount of 10% by weight or more and 30% by weight or less, and the carbon fiber in an amount of 5% by weight or more and 20% by weight or less when the entire resin composition is determined to be 100% by weight.

According to a crown retainer (11) of a ball guide type, a pocket (9) of the retainer (11) has a straight surface (9a) and a tapered surface (9b) where a ball (7) comes into surface contact therewith. A connection point (9c) between the straight surface (9a) and the tapered surface (9b) is on an inner diameter side of an intersection position (I) between an extension plane (F) of a rolling element equatorial plane and a wall surface of the pocket (9). In a two-dimensional cross section passing through centers (O) of a plurality of balls (7), a distance (P) between the ball (7) and the wall surface of the pocket (9) in the extension plane (F) in a neutral position is smaller than a shortest distance (T) between the tapered surface (9b) and the ball (7) in a direction perpendicular to a straight line (L).

Bearing assemblies, such as angular contact bearing assemblies, and methods of producing the same are disclosed. One angular contact ball bearing may include an inner ring and an outer ring, the inner ring having an outer raceway and the outer ring having an inner raceway. A plurality rolling elements may be arranged between the outer raceway and the inner raceway. The outer raceway may be formed by an extrusion of the inner ring and/or the inner raceway may be formed by an extrusion of the outer ring. The raceways may be extruded in their final contour, without any cutting.

Two hybrid ball bearings and a compressor bearing arrangement with two hybrid ball bearings for a rotatable support of a rotor of the compressor versus a stator of the compressor. The two hybrid ball bearings are arranged face-to-face or back-to-back, are configured with an optimal axial clearance depending on the inner diameter of a ring-shaped inner raceway element one of the hybrid ball bearings respectively a pitch diameter of one of the two hybrid ball bearings for a long bearing life in connection with an optimal compressor operating performance.

Cages for ball bearings are disclosed. In one example, a ball bearing cage includes two side rings interconnected by webs. Rolling element pockets, each of which may have a square basic shape with rounded corners, may be formed in a circumferential direction between the webs. The side rings, together with the webs, may form a guide contour of each rolling element pocket. The pockets may have four convex side contours between the corners thereof, and the side contours may point in a direction opposite to rounded portions in the corners.

To provide a retainer for a thrust bearing, which is to be assembled and decomposed regularly for being washed, having superior ball retaining performance itself and being attached and detached easily, and a thrust bearing having the retainer. A retainer for a thrust bearing 1, which retains a plurality balls intervened between a pair of raceway rings in a thrust bearing, is formed of a ring shaped plate member 2 formed of an injection molded body of a resin composition containing fluororesin, which is capable of injection molding, as a base resin. The ring shaped plate member 2 includes a plurality of ball pockets 3 in a circumferential direction of a ring shape. Each of the ball pockets 3 includes a claw portion divided into two portions 3a or more to retain a ball 5 in a detachable manner. The claw portion 3a is defined by a slit 4 formed on at least one surface 2a among facing surfaces of the ring shaped plate member 2 facing raceway rings, the slit 4 being formed around an opening 3d of the ball pocket 3.

A crown type cage for a ball bearing includes an annular main portion, a plurality of pillar portions protruding in an axial direction from the main portion at predetermined intervals in a peripheral direction, and a spherical pocket formed between the adjacent pillar portions and capable of holding balls. The pillar portion has a pair of claw portions of which tip end portions are spaced apart from each other, and a connection portion that connects the pair of claw portions. A bottom surface of the main portion is provided with a part protruding in the axial direction.

A synthetic resin rolling bearing retainer is to be arranged between an inner ring and an outer ring of a rolling bearing. A plurality of guided portions protruding radially outward from an outer diameter surface of the retainer is provided along a circumferential direction of the outer diameter surface. Each of the guided portions has a guide surface protruding to be in sliding contact with the outer ring, a chamfered portion formed at an edge portion of the guide surface, and a groove portion formed at a portion of the guide surface in an axial direction. The guide surface and the chamfered portion have surface properties where an arithmetic average roughness Ra is 1.0 to 9.8 m and a maximum height Rt is 10.1 to 102.9 m. A parting line is provided radially inside the guide surface.

A high-speed ball bearing includes an outer ring, an inner ring, a plurality of balls, and a ball retainer. The ball retainer includes a plurality of pocket holes for arranging a plurality of balls, an inner circumferential surface of each of the pocket holes have a spherical surface is coaxial to the ball. A gap between an outer circumferential surface of the ball retainer and an inner circumferential surface of the ring is defined as a first gap, and a gap between the pocket hole and the corresponding ball is defined as a second gap. The first gap and the second gap have the following relationship: W2=(W1r)A.