Force coupling or torque coupling assemblies, apparatuses, systems, and methods include assemblies that each include superhard contact elements. At least some of the superhard contact elements may be configured to remain in contact with each other when a force is applied between the assemblies.

Force coupling or torque coupling assemblies, apparatuses, systems, and methods include assemblies that each include superhard contact elements. At least some of the superhard contact elements may be configured to remain in contact with each other when a force is applied between the assemblies.

Force coupling or torque coupling assemblies, apparatuses, systems, and methods include assemblies that each include superhard contact elements. At least some of the superhard contact elements may be configured to remain in contact with each other when a rotational force and/or a thrust force is applied between the assemblies.

A lubricating system is disclosed. The lubricating system includes: at least one first to-be-lubricated component, wherein an inlet of each of the at least one first to-be-lubricated component is connected with a first lubrication oil inlet pipe, and an outlet of the each of the at least one first to-be-lubricated component is connected with a first lubrication oil outlet pipe; and at least one second to-be-lubricated component, wherein an inlet of each of the second to-be-lubricated component is connected with a second lubrication oil inlet pipe, and an outlet of the each of the at least one second to-be-lubricated component is connected with a second lubrication oil outlet pipe. An operating pressure of the each of the at least one first to-be-lubricated component is different from a working pressure of the each of the at least one second to-be-lubricated component.

A downhole-type device includes an electric machine. The electric machine includes an electrical rotor configured to couple with a device to drive or be driven by the electric machine. An electrical stator surrounds the electric rotor. The electric stator includes a seal configured to isolate stator windings from an outside, downhole environment. An inner surface of the seal and an outer surface of the electric rotor define an annulus exposed to the outside environment. A bearing couples the electric rotor to the electric stator. A lubrication system is fluidically coupled to the downhole-type device. The lubrication system includes a topside pressure pump and a downhole-type distribution manifold configured to be used within a wellbore. The distribution manifold is fluidically connected to the topside pressure pump and the bearing to receive a flow of lubricant from the topside pressure pump.

A modular anti-rotation device for preventing rotation with respect to the central axis of a drilling tool in a borehole and for producing a notch in a borehole surface. The anti-rotation device includes an upper fixture portion and a lower fixture portion in axial alignment. The upper fixture portion and the lower fixture portion are connected by yoke assemblies. Each yoke assembly is connected to the fixture portion and fixture portion at one end, and forming an articulated joint of the upper yoke assembly and the lower yoke assembly at a distal end opposite the first end. A roller is connected at each joint, connecting the upper and lower yoke assemblies. The rollers engage vertically with a borehole surface, the rollers travelling axially, as a drill shaft penetrates into the borehole, the rollers simultaneously preventing radial movement of the anti-rotation device and prevent rotation with respect to the central axis of the borehole.

A rotary actuator assembly can include a fluid motor with a rotor that displaces with hypocyclic precessional motion within a stator in response to fluid flow through the fluid motor, and a gear reducer section including an input gear that is fixed relative to the rotor and displaces with the hypocyclic precessional motion relative to an output gear. Another rotary actuator assembly can include a fluid motor with a rotor having a central longitudinal axis that rotates about a central longitudinal axis of a stator, and a gear reducer section including an input gear that rotates with the rotor and displaces relative to an output gear, and the input gear having the same central longitudinal axis as the rotor. A well system can include at least two fluid motors, and fluid flow through one fluid motor causes rotation of the other fluid motor in the well.

A high-power turbine fracturing system may include a lubrication system, which may include a first lubrication unit configured to lubricate a plunger pump. The first lubrication unit may further include a high-pressure lubrication unit. The high-pressure lubrication unit may include a high-pressure motor, a high-pressure pump, and a high-pressure oil line. The high-pressure motor may be configured to drive the high-pressure pump, which may be configured to pump high-pressure lubricating oil into the high-pressure oil line. The high-pressure oil line may be configured to lubricate at least one of connecting rod bearing bushes or crosshead bearing bushes in the plunger pump.

A thrust bearing is described comprising first and second bearing assemblies (15, 17) rotatable relative to each and a plurality of axially arranged bearing stages (14a, 14b) formed between the first and second bearing assemblies (15, 17). Each bearing stage comprises a first load shoulder (16) provided on the first bearing assembly (15), a second load shoulder (18) provided on the second bearing assembly (17), a bearing structure (30) defined between the first and second load shoulders; and an extrudable component (32) forming part of the bearing structure. Wherein axial load applied between the first and second bearing assemblies (15, 17) in a first relative axial direction is transmitted between respective pairs of first and second load shoulders via the extrudable components (32) of respective bearing structures (30). The extrudable components (30) provide for load balancing between each bearing stage (14a, 14b).

A drilling system for drilling a borehole. The drilling system may include a drill string, a drill bit coupled to the drill string, a mud motor coupled to the drill string uphole of the drill bit and operable to rotate the drill bit via a driveshaft, a bearing assembly coupled to a downhole end of the mud motor and operable to support the driveshaft, and a rotary steerable system (“RSS”) operable to push the drill bit in a desired direction via pads extended using drilling fluid flowing through the driveshaft and to the RSS. The bearing assembly may include bearings positioned circumferentially around a bore of the bearing assembly, a fluid flowpath through the bearings to allow drilling fluid to pass through the bearings, and a choke assembly positioned in the fluid flowpath and operable to restrict a flow of the drilling fluid through the fluid flowpath.