One aspect of an electric actuator of the present invention includes: a motor having a motor shaft rotatable about a motor axis; a transmission mechanism coupled to one side in the axial direction of the motor shaft; an output shaft extending in the axial direction of the motor shaft and to which rotation of the motor shaft is transmitted via the transmission mechanism; and a rolling member group including three or more rolling members arranged to surround the motor axis. The motor shaft is a hollow shaft. At least a part of the output shaft is located inside the motor shaft. The motor shaft and the output shaft are supported with each other in the axial direction and the radial direction via the rolling member group.

A ball bearing cage has a radially encircling, annular body, on which in the circumferential direction, substantially evenly distributed, axially projecting webs having a predefinable axial length are arranged. The webs form a plurality of axially open ball pockets on one side for accommodating a corresponding number of balls having a predefinable ball diameter. At least for one web, a guide section is formed to bring same into an engagement with a running groove of a ball bearing ring. The axial length of the webs corresponds to at least the ball diameter. There is also described a ball bearing having such a ball bearing cage.

A procedure for mounting a hub bearing assembly including a rotatable hub, and a bearing unit having a stationary radially outer ring, and two rolling bodies disposed between the radially outer ring and the hub, and executing the steps of hammering a first seal on the hub, mounting a cage on the seal seat, providing the outer ring assembly in axially offset manner relative to the hub, mounting the rolling bodies axially externally from the axially inner side, combining the hub to the outer ring, positioning the outer ring inclination at a predetermined angle, mounting the rolling bodies from the axially inner side, aligning the hub to the radially outer ring, snap insertion of the cage, on rolling bodies from the axially outer side and the cage, on rolling bodies from the axially inner side, hammering a second seal on its seat, from the axially inner side.

Provided are that a cage for a rolling bearing in which seizure or break is not generated under a condition of a high temperature and a high speed in which a dm.Math.n value is not less than 80×10.sup.4, and a rolling bearing using the cage. The rolling bearing 1 is provided with an inner ring 2, an outer ring 3, a plurality of rolling elements 4 interposed between the inner ring and the outer ring and a cage 5 which retains the rolling elements 4. The cage 5 is formed by injection molding a resin composition. The resin composition comprises polyamide resin made from a dicarboxylic acid component and a diamine component as a base resin and a fiber reinforcing member added. The dicarboxylic acid component contains terephthalic acid as a main component. The diamine component contains 1,10-diaminodecane as a main component. The fiber reinforcing member contains 15 to 50 mass % of glass fibers or 10 to 35 mass % of carbon fibers based on the whole resin composition.

A rolling element bearing (1) that includes a plurality of balls (4) as rolling elements guided in a cage (5). A lubricant channel (19) is formed in snap-in pockets (8) in a region between a lateral ring section (6) and the central ball (4) track, between the ball (4) and the adjoining web section (7) and/or the adjoining lateral ring section (6), which fluidically connects the radial outer side and the radial inner side of the cage (5). In order for the rolling element bearing (1) lubricant supply to be improved, on the web sections (7), an outer block section (10) is formed on the radial outer side and/or an inner block section (11) is formed on the radial inner side, which project relative to the lateral ring section (6), in the radial direction in relation to the bearing axis L, and reduce the available rolling element space between two adjoining balls (4).

A rolling bearing includes an inner ring, an outer ring, a plurality of rolling elements, and a cage. The cage includes an annular body, a plurality of cage prongs, and guide portions placed inward of the cage prongs in the radial direction of the cage such that the guide portions extend from a radially inner part of the annular body toward a second side in the axial direction of the cage, the guide portions being configured to position the cage by making contact with an inner ring raceway. The cage has a groove so as to connect pockets adjacent to each other in the circumferential direction, the groove being configured such that lubricant is present in the groove and a groove width of the groove is increased in the radial direction in the center of the groove in the circumferential direction.

A rolling bearing includes an outer ring, an inner ring disposed coaxially with the outer ring, the inner ring being on an inner peripheral side of the outer ring. The rolling bearing includes multiple rolling elements disposed between the outer ring and the inner ring. The rolling bearing includes a strain gauge configured to detect strain of the outer ring or the inner ring. The strain gauge includes a resistor formed of a Cr composite film.

A rolling bearing retainer which is formed by insert molding a resinous material together with a core member within a mold, in which the core member is embedded within a resin part made of the resinous material and a support area exposure part is provided at a plurality of locations of the resin part for exposing a support area of the core member supported within a cavity of the mold. The resin part includes a ring shaped body and a plurality of support column bodies extending axially from the ring shaped body and defining a pocket for retaining a rolling element therebetween, and the core member is provided with a ring shaped body embedded part and a plurality of support column body embedded parts extending from the ring shaped body embedded part.

A cage has an annular portion positioned on an axially first side of balls and a plurality of cage bars provided to extend from the annular portion toward an axially second side. Pockets each housing a corresponding one of the balls correspond to areas each located on the axially second side of the annular portion and between two cage bars adjacent to each other in a circumferential direction. Each of the balls is exposed from axially-second-side ends of the corresponding cage bars over an axially-second-side range. An axial dimension of the range over which the ball is exposed from the axially-second-side ends is 30% or more and 50% or less of the diameter of the ball.

A ball bearing is provided which includes a cage circular annular portion and a seal member. The cage circular annular portion has a cage-side sliding contact surface axially opposed to the seal member and configured to come into sliding contact with the seal member. The seal member has a seal-side sliding contact surface configured to come into sliding contact with the cage-side sliding contact surface. A plurality of axial protrusions each having an axially convex circular arc shape in cross sections along a circumferential direction are formed on one of the cage-side sliding contact surface and the seal-side sliding contact surface at constant pitches in the circumferential direction.