A tool holder of a machine tool, in which the machine tool includes a spindle head and a spindle supported by the spindle head, includes: a shank portion attached to the spindle; a rotary portion integrally provided to the shank portion and to which a welding tool (processing tool) used for friction stir welding is attachable; a bearing mechanism (bearing) supporting the rotary portion so that the rotary portion is rotatable; and a bearing holder holding the bearing mechanism, in which the bearing holder is disposed facing the spindle head and is capable of transmitting a load applied to the bearing mechanism to the spindle head.

A rolling-element bearing for an electromagnetic solenoid includes a hollow cylindrical cage with a plurality of spherical pockets formed around a first circumference and a second circumference of the cage. The pockets around the first circumference are offset from the pockets around the second circumference. Spherical rolling elements are provided in the spherical pockets and are captured for free rotation in the first pockets and second pockets.

A thrust bearing includes a first axial end washer defining thereon a first race, a second axial end washer defining thereon a second race, a one-piece, radially-inner washer having a first axial end engaged with the first axial end washer and having a second axial end defining thereon a third race, and a one-piece, radially-outer washer having a first axial end defining thereon a fourth race and having a second axial end engaged with the second axial end washer. A first set of tapered rolling elements is supported between the first race and the fourth race and a second set of tapered rolling elements is supported between the second race and the third race. The first and second sets of tapered rolling elements are both axially and radially offset from one another.

A thrust bearing includes a first axial end washer defining thereon a first race, a second axial end washer defining thereon a second race, a one-piece, radially-inner washer having a first axial end engaged with the first axial end washer and having a second axial end defining thereon a third race, and a one-piece, radially-outer washer having a first axial end defining thereon a fourth race and having a second axial end engaged with the second axial end washer. A first set of tapered rolling elements is supported between the first race and the fourth race and a second set of tapered rolling elements is supported between the second race and the third race. The first and second sets of tapered rolling elements are both axially and radially offset from one another.

First and second bearing cage halves each having an annular base body and a plurality of pins extending from the base body and a plurality of pin receptacles, the first and second cage haves forming a bearing cage when the pins are received into the pin receptacles. A body of sacrificial material is located on the pins and/or in the pin receptacles which body is configured to be melted ultrasonically to join the first cage half to the second cage half and form the bearing cage.

A roller retainer cage for a roller thrust bearing, including a first cage half with an annular portion, a first flange extending axially from an inner peripheral edge of the annular portion and a second flange extending axially from an outer peripheral edge of the annular portion, a second cage half including an annular portion, a first flange extending axially from an inner peripheral edge of the annular portion and a second flange extending axially from an outer peripheral edge of the annular portion, wherein the first flange of the first cage half is disposed radially-outwardly of the first flange of the second cage half, the second flange of the first cage half is disposed radially-inwardly of the second flange of the second cage half, and the first cage half is comprised of a through-hardened metal.

A double row axial roller bearing assembly includes a compressible ring between the two rows. This compressible ring prevents excessive axial forces if the respective shafts impact one another after becoming axially separated. One embodiment is fully unitized such that all parts of the bearing assembly remain with one of the two shafts if the shafts become axially separated. Another embodiment is semi-unitized such that one row of rollers and the compressible ring remain with one of the shafts while the other row of rollers remains with the other shaft. In both cases, all bearing components are prevented from falling out of position such that they return to their proper axial and radial position when the shafts come back together.

A cup assembly for a pin of a universal joint bearing includes a cup, a first seal ring attached to the cup, and a second seal ring. The first seal ring includes an elastic element and a spring element configured to preload the elastic element toward the pin, the second seal ring includes a dimensionally stable seal section that is configured to sealingly interact with the pin, and the second seal ring is connected to the cup either directly, or via the elastic element or via an elastic retainer. Also a method of installing the cup assembly.

A roller retainer cage for a roller thrust bearing, including a first cage half with an annular portion, a first flange extending axially from an inner peripheral edge of the annular portion and a second flange extending axially from an outer peripheral edge of the annular portion, a second cage half including an annular portion, a first flange extending axially from an inner peripheral edge of the annular portion and a second flange extending axially from an outer peripheral edge of the annular portion, wherein the first flange of the first cage half is disposed radially-outwardly of the first flange of the second cage half, the second flange of the first cage half is disposed radially-inwardly of the second flange of the second cage half, and the first cage half is comprised of a through-hardened metal.

A thrust bearing assembly comprises a cage including an annular portion. A first flange extends axially from an inner peripheral edge of the annular portion, and a second flange extends axially from an outer peripheral edge of the annular portion. A first plurality of roller pockets are defined by the annular portion, the first roller pockets of the first plurality of roller pockets being spaced evenly about the annular portion. A second plurality of roller pockets are defined by the annular portion, the second roller pockets of the second plurality of roller pockets being evenly spaced about the annular portion so that each second roller pocket is disposed between adjacent first roller pockets.