A rolling element shaft assembly includes a solid shaft having a first end and a second end, a tubular shaft configured to receive the shaft first end, and a bearing sleeve coupled to the solid shaft. The bearing sleeve includes a first portion defining a first edge, a second edge, and at least one first bearing aperture, and a second portion defining a third edge, a fourth edge, and at least one second bearing aperture. The first portion is configured to couple to the second portion about the solid shaft. The bearing sleeve further includes at least one first bearing disposed within the at least one first bearing aperture and at least one second bearing disposed within the at least one second bearing aperture.

A cage segment for a rolling bearing, in particular a taper roller bearing, includes: two side plates; at least two bridges connecting the two side plates; a complete rolling element pocket being between each pair of bridges; and an incomplete rolling element pocket formed by regions of the two side plates which project beyond the bridges in a circumferential direction of the cage segment. Two end faces of each side plate are contoured differently, in particular are convex in one case and flat in the other case.

A rolling element shaft assembly includes a solid shaft having a first end and a second end, a tubular shaft configured to receive the shaft first end, and a bearing sleeve coupled to the solid shaft. The bearing sleeve includes a first portion defining a first edge, a second edge, and at least one first bearing aperture, and a second portion defining a third edge, a fourth edge, and at least one second bearing aperture. The first portion is configured to couple to the second portion about the solid shaft. The bearing sleeve further includes at least one first bearing disposed within the at least one first bearing aperture and at least one second bearing disposed within the at least one second bearing aperture.

A cage segment for a rolling bearing, in particular a taper roller bearing, includes: two side plates; at least two bridges connecting the two side plates a complete rolling element pocket being between each pair of bridges and an incomplete rolling element pocket formed by regions of the two side plates which project beyond the bridges in a circumferential direction of the cage segment. Two end faces of each side plate are contoured differently, in particular are convex in one case and flat in the other case.

One aspect of the present disclosure provides a strain wave gear device including an internal gear, an external gear and a wave generator. The wave generator has a cam and a fourth bearing. The cam has a non-circular outer peripheral surface, and the fourth bearing is positioned between the inner peripheral surface of the external gear and the outer peripheral surface of the cam. The fourth bearing has an outer ring, an inner ring, a plurality of balls, and a retainer. The strain wave gear device includes a restricting portion provided such that the restricting portion can avoid touching the retainer. The restricting portion can restrict the fourth bearing from moving in the direction extending along the axis of rotation.

Systems and methods for reducing friction between a casing string and a bore of a subterranean well when moving the casing string within the bore of a subterranean well include a roller bearing assembly. The roller bearing assembly has a bearing body and a plurality of spherical bearings spaced around an outer diameter of the bearing body. The bearing body is secured in line with the casing string.

The invention relates to a rolling bearing, in particular in the form of an open-center large rolling bearing, comprising a large number of rolling elements, which are held between at least two raceways, on which the rolling elements roll, wherein spacers are provided between the rolling elements, which spacers keep the rolling elements spaced apart from each other. According to the invention, at least one of the raceways has, in a center portion, an approximately groove-shaped longitudinal recess, in which support arms provided between the spacers run, which support arms reach around the rolling element between two adjacent spacers and support the adjacent spacers against each other in the running direction of the rolling elements.

Systems and methods for reducing friction between a casing string and a bore of a subterranean well when moving the casing string within the bore of a subterranean well include a roller bearing assembly. The roller bearing assembly has a bearing body and a plurality of spherical bearings spaced around an outer diameter of the bearing body. The bearing body is secured in line with the casing string.

An assembly for a rolling element bearing, the assembly including a first cage segment and a second cage segment which are releasably connectable to one another, and at least one rolling element. The assembly further comprises a cage pocket for receiving the at least one rolling element. The cage pocket is at least partly defined by a cage pocket wall of at least one of the first cage segment and the second cage segment. The assembly is such that, when the at least one rolling element is in the cage pocket, the at least one rolling element prevents the first cage segment and the second cage segment from being releasably disengaged. A rolling element bearing can incorporate such an assembly.

The invention relates to a rolling bearing, in particular in the form of an open-center large rolling bearing, comprising a large number of rolling elements, which are held between at least two raceways, on which the rolling elements roll, wherein spacers are provided between the rolling elements, which spacers keep the rolling elements spaced apart from each other. According to the invention, at least one of the raceways has, in a center portion, an approximately groove-shaped longitudinal recess, in which support arms provided between the spacers run, which support arms reach around the rolling element between two adjacent spacers and support the adjacent spacers against each other in the running direction of the rolling elements.