A roller screw mechanism comprising a screw having an outer threading; a nut arranged around and coaxially to the screw, the nut having an inner threading; and a plurality of mutually identical rollers interposed between the screw and the nut. Each mutually identical roller having an outer threading engaged with the outer and inner threadings of the screw and of the nut. The threading of each mutually identical roller being prolonged axially at each end by teeth respectively engaged with teeth of two annular crown rings fixed in an unthreaded part of the bore of the nut. Each of the mutually identical rollers comprises an angular visual positioning feature. The nut comprises an angular visual positioning feature making it possible to angularly place the rollers in the crown ring.

Methods and apparatus for preloading a bearing are provided. These methods and apparatus include preload monitoring devices whereby the mechanic can accurately monitor and regulate the preload on a bearing or bearing assembly. Aspects of the invention may also be used to adjust the endplay on a bearing or a bearing assembly. In one aspect, the preload on the bearing is transmitted through a housing having a fluid pressure that can be detected and monitored. An apparatus for precisely rotating a nut and a tool for precisely rotating a nut are also provided. A bearing retaining nut arrangement that permits the loading or evaluating of a bearing inner race is also provided. The bearing retaining nut arrangement includes a first load-setting nut, a lock washer, and a second jam nut that secures the arrangement to a shaft.

Methods and apparatus for preloading a bearing are provided. These methods and apparatus include preload monitoring devices whereby the mechanic can accurately monitor and regulate the preload on a bearing or bearing assembly. Aspects of the invention may also be used to adjust the endplay on a bearing or a bearing assembly. In one aspect, the preload on the bearing is transmitted through a housing having a fluid pressure that can be detected and monitored. An apparatus for precisely rotating a nut and a tool for precisely rotating a nut are also provided. A bearing retaining nut arrangement that permits the loading or evaluating of a bearing inner race is also provided. The bearing retaining nut arrangement includes a first load-setting nut, a lock washer, and a second jam nut that secures the arrangement to a shaft.

An apparatus for preloading a bearing includes an attaching member, a frame, a plurality of extensions, and an adjustment mechanism. The attaching member is releasably attachable to a threaded shaft of an axle or spindle of a wheel hub assembly. The frame is axially separated from, and coupled to, the attaching member to allow the frame to move relative to the attaching member in an axial direction along the longitudinal axis. The plurality of extensions is configured to contact at least one of a wheel hub or a bearing of the wheel hub assembly when the attaching member is attached to the threaded shaft. The adjustment mechanism is configured to move the frame and the plurality of extensions axially towards the wheel hub assembly to apply a preload to a bearing within the wheel hub assembly.

An alignment device aligns rollers R in an annular shaped alignment space 24 in parallel to each other while at the same time prevents damage from occurring on rolling surfaces of rollers R. Plural rollers R that are arranged in a row in an axial direction are sequentially supplied into an annular shaped alignment space 24 that is formed in a main jig 14 in a direction that coincides with a width direction of the alignment space 24. The plural rollers R are aligned in an annular shape so as to be in parallel to each other by alignment-fluid-supply means 16 spraying air onto a roller R that is in a supply position in the alignment space 24 from a direction that is orthogonal to the roller R supply direction and moving the roller R in a circumferential direction of the alignment space 24, and then supplying a next roller R into the alignment space 24.

A rolling-element bearing in which a rolling element is retained in each of retaining openings formed in a retainer and method for manufacturing the bearing are provided. Each retaining opening is defined by a pair of inner side faces facing each other, and a pair of inner end faces facing each other. In the manufacturing method, with a support die being brought into contact with one of the inner side faces and the inner end faces of one of the retaining openings, the outer and inner circumferential surfaces of the retainer are pressed by an outer punch and an inner punch. Accordingly, on at least one of the inner side faces and the inner end faces, a first retaining piece and a second retaining piece for preventing the rolling element from falling off are formed on the outer circumferential surface and the inner circumferential surface of the retainer, respectively.

A tool for installing a locking collar on a bearing using an air hammer is provided. The tool includes a first portion having an air hammer coupling portion configured to couple to the air hammer. A torque arm is coupled to the first portion. A collar-engaging portion is coupled to the torque arm and is configured to couple to a locking collar to impart rotational impacts to the locking collar when the air hammer is actuated.

Methods and apparatus for preloading a bearing are provided. These methods and apparatus include preload monitoring devices whereby the mechanic can accurately monitor and regulate the preload on a bearing or bearing assembly. Aspects of the invention may also be used to adjust the endplay on a bearing or a bearing assembly. In one aspect, the preload on the bearing is transmitted through a housing having a fluid pressure that can be detected and monitored. An apparatus for precisely rotating a nut and a tool for precisely rotating a nut are also provided. A bearing retaining nut arrangement that permits the loading or evaluating of a bearing inner race is also provided. The bearing retaining nut arrangement includes a first load-setting nut, a lock washer, and a second jam nut that secures the arrangement to a shaft.

Various embodiments of stand-off devices and methods are disclosed. The stand-off device can space a bearing assembly apart from a support, such as a frame of a conveyor belt, thereby providing access between the bearing assembly and the frame, such as for cleaning fluid. Certain embodiments of the stand-off device include a first end and a second end, with the first end being receivable in a securing hole of the bearing assembly and the second end configured to protrude from the bearing assembly.