An object of the present invention to provide a tapered roller bearing in which a flange portion is formed at a large-diameter end of an outer ring track surface of an outer ring, capable of providing high moment stiffness and long life without extremely decreasing its pure axial load capacity. The tapered roller bearing comprising: an outer ring 12 having an outer ring track surface 12a on its inner circumferential surface; an inner ring 13 having an inner ring track surface 13a on its outer circumferential surface; a plurality of tapered rollers 14 rotatably disposed between the outer ring track surface 12a and the inner ring track surface 13a; and a retainer 15 having a plurality of pockets for retaining the plurality of tapered rollers 14 at a predetermined interval; the outer ring track surface 12a of the outer ring 12 having a small-diameter end and a large-diameter end, the inner ring track surface 13a of the inner ring 13 having a small-diameter end and a large-diameter end, and, of these four ends, a flange portion 12b that protrudes radially inwardly is formed at the large-diameter end of the outer ring track surface 12a of the outer ring 12; wherein the tapered roller bearing has a contact angle greater than 35° and a roller angle not greater than 3.5°.

A holder of a tapered roller bearing is made of a resin, has a first gap between an axially inner end surface of a small-diameter-side annular part and small-diameter-side end surfaces of tapered rollers, has a second gap between an axially inner end surface of a large-diameter-side annular part and large-diameter-side end surfaces of the tapered rollers, and is provided to be capable of moving within a prescribed range along the axial direction. The surface of the axially inner end surface of the large-diameter-side annular part is rough, the large-diameter-side annular part is provided with one or more grooves which are oil-holding parts that hold the lubricating oil, and ends of the grooves are positioned to be capable of coming into contact with the tapered rollers.

A cage for a tapered roller bearing includes a large-diameter-side annular portion circumferentially extending along large end surfaces of a plurality of tapered rollers; a small-diameter-side annular portion circumferentially extending along small end surfaces of the tapered rollers; and a plurality of pillars coupling together the large-diameter-side annular portion and the small-diameter-side annular portion. The large-diameter-side annular portion has large-diameter-side pocket surfaces opposed to the large end surfaces of the respective tapered rollers. The large-diameter-side pocket surfaces include oil retaining holes including blind holes, and being configured to receive and retain lubricating oil by capillary action.

An object of the present invention to provide a tapered roller bearing in which a flange portion is formed at a large-diameter end of an outer ring track surface of an outer ring, capable of providing high moment stiffness and long life without extremely decreasing its pure axial load capacity. The tapered roller bearing comprising: an outer ring 12 having an outer ring track surface 12a on its inner circumferential surface; an inner ring 13 having an inner ring track surface 13a on its outer circumferential surface; a plurality of tapered rollers 14 rotatably disposed between the outer ring track surface 12a and the inner ring track surface 13a; and a retainer 15 having a plurality of pockets for retaining the plurality of tapered rollers 14 at a predetermined interval; the outer ring track surface 12a of the outer ring 12 having a small-diameter end and a large-diameter end, the inner ring track surface 13a of the inner ring 13 having a small-diameter end and a large-diameter end, and, of these four ends, a flange portion 12b that protrudes radially inwardly is formed at the large-diameter end of the outer ring track surface 12a of the outer ring 12; wherein the tapered roller bearing has a contact angle greater than 35° and a roller angle not greater than 3.5°.

A roller and cage assembly includes: a cage (12) including a pair of rings (11) and a plurality of cage bars (21) extending in an axial direction and connecting the rings (11) to each other; and rollers disposed in pockets between the cage bars (21, 21) adjacent to each other in a circumferential direction. The cage bar (21) includes an end portion (22) and a middle portion located radially inward from the end portion (22). The end portion (22) has an outer retaining protrusion (25) formed therein, the outer retaining protrusion protruding into the pocket and configured to contact the roller to restrict radially outer movement of the roller. The end portion (22) of the cage bar (21) has an oil groove (31) in an inner peripheral surface (26) thereof, the oil groove extending in the circumferential direction and connecting to the outer retaining protrusion (25).

A rolling-element bearing unit includes at least one outer ring, at least one inner ring, at least one cage, and a plurality of rolling elements between the outer ring and the inner ring and disposed in pockets of the cage. At least one auxiliary ring is disposed axially adjacent to the outer ring, and the cage includes connecting elements, such as radially outwardly extending lugs, for captively connecting the auxiliary ring to the cage.

In a tapered roller bearing, a large-diameter-side annular portion includes large-diameter-side pocket surfaces opposed to large end surfaces of respective tapered rollers; and oil retaining recesses each having an opening spanning an inner peripheral surface of the large-diameter-side annular portion and each of the large-diameter-side pocket surfaces. Each of the oil retaining recesses has an inner surface having a radially inwardly facing surface portion which is an inclined surface that is radially inwardly inclined toward the corresponding tapered roller.

A bearing cage includes a first circular ring; a second circular ring provided to be spaced apart from the first ring in a coaxial relationship with the first ring; a plurality of pillars provided in a circumferential direction of the first ring and the second ring, one end of the pillar being connected to the first ring and the other end of the pillar being connected to the second ring; a plurality of pockets provided in the circumferential direction and configured to provide a space in which a bearing roller is accommodated, the pocket being formed to be surrounded by the first ring, the pillars and the second ring; and first reservoirs provided in the pillars and comprising a first storage space for storing lubricant.

A cage includes: a first holding portion in which a plurality of radial rollers is held; a second holding portion in which a plurality of thrust rollers is held; and a connecting portion via which the first holding portion is connected to the second holding portion. The first holding portion, the second holding portion, and the connecting portion are molded integrally by a resin member.

A radial roller bearing cage includes a pair of annular bodies; and a plurality of bars by which the annular bodies are axially connected to each other. The annular bodies and the bars are integrally formed by resin molding. A plurality of pockets separated from each other by the bars is provided between the annular bodies. A projection projecting radially inwardly is provided in at least one of parts of at least one of the annular bodies, the parts axially facing the pockets, respectively.