A bearing assembly includes a roller bearing unit, an inner race and an outer race. The roller bearing unit is formed of polycrystalline super-hard material having a mean mass density of at most 4.5 g/cm.sup.3 and a volume-weighted arithmetic mean thermal conductivity of at least 100 W/m.Math.K.

A method for machining ribs or grooves on a workpiece such as a shaft or an air or gas axial bearing intended to be rotated about a longitudinal axis of a centrifugal compressor. All of the ribs or grooves are obtained at once by the machining tool on a workpiece portion driven such that it rotates, by moving the workpiece or the tool holder in a longitudinal machining direction, the machining tool moving back and forth with a machining position in contact with the workpiece and a position wherein it is not in contact with the workpiece from the start to the end of the workpiece portion. The back-and-forth movements of the machining tool are synchronised with the sinusoidal program set up in the machining unit, as well as with the desired, programmed arrangement of the ribs or grooves to be produced on the workpiece portion.

A bearing component, such as a bearing roller or a bearing ring, has an exterior surface and includes at least one interior region made of a recycled material which region is spaced from and does not form any part of the exterior surface. The recycled material and the unrecycled material may each include silicon nitride and/or sialon and/or silicon carbide and/or a ceramic material. Also a method of forming the component.

A thrust bearing pad includes a relatively low wear and low friction contact layer disposed on a metallic substrate. The metallic substrate allows a manufacturer to couple the thrust bearing pad to a corresponding metallic thrust bearing in a relatively secure manner while the contact layer extends the operating life of the thrust bearing and minimizes maintenance.

Described herein are methods and system for welding, for example, girders. The method may include activating a homopolar generator. The method may include applying a force to two metal girders at a desired coupling joint. The method may include generating an electrical pulse using the homopolar generator and conducting the electrical pulse to the desired coupling joint to increase a temperature of the girders. The method may include forming a weld at the desired coupling joint attaching the two metal girders at the desired coupling joint. In some embodiments, the homopolar generator may include a radial bearing rotor including a rotatable shaft and a bearing assembly. The bearing assembly may include nonmagnetic bearings. The homopolar generator may include a field coil. The homopolar generator may include a brush actuation mechanism which when activated engages a plurality of brush devices to the radial bearing rotor.

The present disclosure provides a bearing design that accommodates misalignment of a rotatable shaft in the bearing and is well suited to usage in a particulate-laden fluid. The bearing can be shaped with a curved surface along a longitudinal axis of the bearing, such as in a curved barrel shape or a ball shape, to provide a point contact instead of a line contact as is the case with conventional plain bearings. The point contact allows the bearing to adjust with a misalignment between ends of the shaft or between the external supports and facilitates the assembly and disassembly of the rotating shaft. Because the bearing compensates for misalignment, the bearing surfaces can have closer tolerances for a smaller gap between the bearing surfaces, which can result in improved performance.

Embodiments of the invention are directed to bearing assemblies configured to effectively provide heat dissipation for bearing elements, bearing apparatuses including such bearing assemblies, and methods of operating such bearing assemblies and apparatuses. In an embodiment, a bearing assembly includes a plurality of superhard bearing elements distributed about an axis. Each superhard bearing element of the plurality of superhard bearing elements has a superhard table including a superhard surface. The bearing assembly includes a support ring structure coupled to the plurality of superhard bearing elements. One or more of the superhard bearing elements includes a superhard table, which may improve heat transfer from such superhard bearing elements.

Bearing assemblies, apparatuses, and motor assemblies using the same are disclosed. In an embodiment, a bearing assembly may include a plurality of superhard bearing elements distributed circumferentially about an axis. Each of the superhard bearing elements may include a bearing surface. The bearing assembly may also include a support ring structure having a support ring that carries the superhard bearing elements. The support ring structure may include at least one erosion resistant region exhibiting a higher erosion resistance than another region of the support ring.

An insulating device for a bearing mountable within a housing, the bearing having an inner ring and an outer ring with an outer circumferential surface and opposing axial ends and a plurality of rolling elements disposed there between. The insulating device comprises: a first annular part, which is adapted to be in contact to the outer circumferential surface of the outer ring, and a second annular part, which is also adapted to be in contact to the outer circumferential surface of the outer ring. The first and second part form the insulation device which is adapted to contact, in an assembled state of the bearing in the housing, both the outer ring and the housing. The first part is thermally conductive and electrically insulating and the second part is electrically insulating and less thermally conductive than the first part or is not thermally conductive.

A bearing assembly includes a roller bearing unit, an inner race and an outer race. The roller bearing unit is formed of polycrystalline super-hard material having a mean mass density of at most 4.5 g/cm.sup.3 and a volume-weighted arithmetic mean thermal conductivity of at least 100 W/m.Math.K.