Embodiments of the invention relate to bearing apparatuses in which one bearing surface of the bearing apparatus includes diamond, while another bearing surface includes a non-diamond superhard material (e.g., silicon carbide). For example, a bearing apparatus may include a bearing stator assembly and a bearing rotor assembly. The bearing stator assembly and bearing rotor assembly each include a support ring and one or more superhard bearing elements generally opposed to one another. The bearing surface(s) of the rotor or stator may include diamond, while the bearing surface(s) of the other of the rotor or stator do not include diamond. Another bearing apparatus may include both thrust- and radial bearing components. The generally opposed thrust-bearing elements may include diamond, while the generally opposed radial bearing elements may not include diamond, but include a non-diamond superhard material, such as silicon carbide.

A radial bearing apparatus including a housing with a housing bore defining a radial bearing housing surface, a shaft extending through the housing bore and defining a radial bearing shaft surface, and a radial bearing contact interface between the radial bearing housing surface and the radial bearing shaft surface for bearing a variable side force applied to the shaft. The radial bearing contact interface includes an oblique section in which the radial bearing housing surface and the radial bearing shaft surface are oblique to each other when the side force is zero and progressively increase in contact in an axial direction in response to an increasing magnitude of the side force.

Embodiments of the invention related to bearing assemblies and methods of forming the bearing assemblies that include at least one superhard bearing element exhibiting a superhard bearing surface having a polished surface finish or a superhard bearing surface having a textured surface. In an embodiment, a bearing assembly includes a support ring. The bearing assembly includes at least one superhard bearing element. The at least one superhard bearing element includes a superhard bearing surface having a polished surface finished or a textured surface. The at least one superhard bearing element is secured to the support ring.

A bearing pressure system includes a bearing assembly having a first component movable against a second component and at least one accumulator in fluid communication with an interface between the first and second components, the at least one accumulator holding a pressurized fluid. A method includes providing a bearing pressure system having a fluid communicable between an accumulator and an interface between components movable relative to each other, providing an amount of pressurized fluid from the accumulator to the interface when the pressure of the fluid at the interface falls below a pressure range being maintained, and transferring an amount of the fluid from the interface to the accumulator when the pressure of the fluid at the interface rises above the pressure range being maintained.

The present disclosure relates to a rotation unit and method for adjusting bearing clearance. The rotation unit includes a shaft that is rotated around its longitudinal axis by a rotating motor. The shaft is supported to a body of the rotation unit by a bearing assembly. The rotation unit further includes an adjusting arrangement for generating pre-load for the bearing assembly and adjusting bearing clearance. The adjusting arrangement includes an axial adjusting space and at least one pair of half-elements arranged between axial adjusting surfaces limiting the adjusting space.

A rotatable bearing assembly transfers a weight of a drill string to a mud motor output shaft extending therethrough. The bearing assembly includes an outer bearing housing, an upper radial bearing assembly providing an upper radial bearing between the outer bearing housing and the output shaft, a balance piston that fluidly seals an upper end of the outer bearing housing and balances a pressure within the outer bearing housing, a lower radial bearing/seal assembly configured to both fluidly seal a lower end of the outer bearing housing and provide a lower radial bearing between the outer bearing housing and the output shaft, and a thrust bearing assembly received within the sealed interior of the outer bearing housing such that the bearing assembly initially operates in a sealed, lubricated mode and then a mud lube mode in the event of one or more seal failures. Other embodiments are also disclosed.

Embodiments of the invention relate to bearing apparatuses in which one bearing surface of the bearing apparatus includes diamond, while another bearing surface includes a non-diamond superhard material (e.g., silicon carbide). For example, a bearing apparatus may include a bearing stator assembly and a bearing rotor assembly. The bearing stator assembly and bearing rotor assembly each include a support ring and one or more superhard bearing elements generally opposed to one another. The bearing surface(s) of the rotor or stator may include diamond, while the bearing surface(s) of the other of the rotor or stator do not include diamond. Another bearing apparatus may include both thrust- and radial bearing components. The generally opposed thrust-bearing elements may include diamond, while the generally opposed radial bearing elements may not include diamond, but include a non-diamond superhard material, such as silicon carbide.

Embodiments disclosed herein are directed to tilting pad bearing assemblies and bearing apparatuses using the same. As will be discussed in more detail below, the tilting pad bearing assemblies include a plurality of tilting pads. The tilting pads include at least one or more first tilting pads and one or more second tilting pads. Each of the first tilting pads includes a first superhard bearing surface having a first material. Each of the second tilting pads includes a second bearing surface having a second material. The first material includes a superhard material and the second material includes a material that is different than the first material.

A walking foot for a drilling rig comprising a foot plate attacheable to a drilling rig by an travel plate, capable of functionally bearing a load in excess a quarter of the weight of a drilling rig, comprising a planar roller array wherein a plurality of load rollers with parallel rotational axes are dispersed both laterally and longitudinally within the plane, so as to fractionalize a weight applied perpendicular to the plane, and thereby promote longitudinal motion of the roller array in a direction perpendicular to the plurality of roller rotational axes.

In an embodiment, a method of fabricating a polycrystalline diamond compact is disclosed. The method includes sintering a plurality of diamond particles in the presence of a metal-solvent catalyst to form a polycrystalline diamond body; leaching the polycrystalline diamond body to at least partially remove the metal-solvent catalyst therefrom, thereby forming an at least partially leached polycrystalline diamond body; and subjecting an assembly of the at least partially leached polycrystalline diamond body and a cemented carbide substrate to a high-pressure/high-temperature process at a pressure to infiltrate the at least partially leached polycrystalline diamond body with an infiltrant. The pressure of the high-pressure/high-temperature process is less than that employed in the act of sintering of the plurality of diamond particles.