A ball bearing assembly includes at least two units being axially coupled together to allow at least one set of plural spherical balls adapted to be installed between at least one pair of two adjacent units of the at least two units.

A large thrust ball bearing, retainer, and raceways, using a surface treatment such as hard anodize, lowers the friction and wear. The retainer, molded in synthetic resin with self-lubricated material reinforced with carbon fiber such as MoS.sub.2, and PTPE, eliminates the thermal viscosity. Multi-segment retainers, each with an inner race-guided configuration, an alternative ball pocket cross-section design with a slotted configuration, reduce the thermal effects, improve the producibility of the retainer, and reduce the manufacturing cost. The pocket design with an oval cross-section instead of a circular cross-section also reduces the localized thermal-induced effect which would otherwise result in a pinching condition between the ball and the retainer. The alternative slotted retainer pocket design increases the compliance between ball/pocket interfaces, which helps to reduce the dynamic effects. The ends of the retainer segments are designed to reduce the interactive transferring, circumferential force between two adjacent segments.

A ball bearing assembly includes at least two units being axially coupled together to allow at least one set of plural spherical balls adapted to be installed between at least one pair of two adjacent units of the at least two units.

A cage for a ball bearing is provided with a wire having a first group of heels spaced apart in the circumferential direction and form a first discontinuous ring, a second group of heels spaced apart in the circumferential direction and form a second discontinuous ring, and a plurality of connecting portions extending between one of the heels of the first group and second group. The connecting portions and the heels of the first group and/or the second group delimit a plurality of spaces each intended to receive a ball of the bearing. The cage also provides at least one interposed part disposed inside each space and is provided with a body for accommodating a ball and coupling means for fastening the body to at least one of the connecting portions of the wire. Each of the bodies of the interposed parts fully positioned in the circumferential direction.

[Problem] To provide a linear motion device using a highly reliable and environmentally friendly separator that improves a dimensional stability, ductility, and adhesion of greases based on poly-?-olefin oil, which are required for separators, and also prevents deformation at high speeds.

[Solution] Provided is a linear motion device including a linear motion body (15) that is fitted onto a screw shaft (11) and moves straight along the screw shaft (11), a large number of balls (B) held in a ball groove (14) formed on an inner surface side of the linear motion body (15) and rolling between the ball groove (14) and the screw shaft (11), a separator (100) interposed 10 between each ball (B), a circulation passage (18) formed in the linear motion body (15) and circulating the ball (B) from one end side of the ball groove (14) to the other end side, where at least one of the separator (100) and the circulation passage (18) is formed from polyamide 410 by injection molding.

A flexible bearing including spacers is provided. The flexible bearing includes: an outer race including a rolling groove; an inner race arranged in the outer race and including a rolling trough corresponding the rolling groove to collectively define a loading passage; rolling elements arranged in the loading passage; and spacers each including a retention section for receiving and retaining the rolling elements. Two adjacent ones of the spacers are in contact engagement with each other with end faces thereof and the two end faces are respectively a concave surface and a convex surface. The concave surface and the convex surface of the spacers are allowed to undergo relative sliding so as to allow the spacers to adjust, with respect to each other, an angular position thereof during an operation of the flexible bearing in order to prevent the spacers from interfering with the outer race or the inner race.

A cage for a ball bearing is provided with a wire having a first group of heels spaced apart in the circumferential direction and form a first discontinuous ring, a second group of heels spaced apart in the circumferential direction and form a second discontinuous ring, and a plurality of connecting portions extending between one of the heels of the first group and second group. The connecting portions and the heels of the first group and/or the second group delimit a plurality of spaces each intended to receive a ball of the bearing. The cage also provides at least one interposed part disposed inside each space and is provided with a body for accommodating a ball and coupling means for fastening the body to at least one of the connecting portions of the wire. Each of the bodies of the interposed parts fully positioned in the circumferential direction.

A hybrid cage includes a unitary annular main frame and a plurality of attachment members fixedly attached to the main frame to define cage pockets for receiving rolling elements. The main frame may be formed from a first material and the plurality of attachment members may be formed from a second material different than the first material.

A separator is provided for a ball bearing including inner and outer rings and a plurality of balls disposed between the inner and outer rings. The separator includes an annular body having a centerline, opposing first and second axial ends spaced apart along the centerline, an inner circumferential surface defining a central pocket sized to receive one of the plurality of balls and an outer circumferential surface defining an outer perimeter. A plurality of inner axial channels extend radially outwardly from the inner circumferential surface and a plurality of outer axial channels extend radially inwardly from the outer circumferential surface, each inner axial channel and each outer axial channel being configured to contain lubricant. Preferably, both the inner and outer axial channels are spaced circumferentially about the centerline and each channel extends entirely axially between the first and second axial ends of the annular body.

A linear motion device includes a linear motion body that is fitted onto a screw shaft and moves straight along the screw shaft, a large number of balls held in a ball groove formed on an inner surface side of the linear motion body and rolling between the ball groove and the screw shaft, a separator interposed between each ball, a circulation passage formed in the linear motion body and circulating the ball from one end side of the ball groove to the other end side, where at least one of the separator and the circulation passage is formed from polyamide 410 by injection molding.