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.

Various embodiments relate to a bearing assembly including a support ring configured to reduce thermal warping under operational temperature conditions, a bearing apparatus that may utilize such a thrust-bearing assembly, and applications that incorporate the disclosed bearing apparatuses such as downhole motors in subterranean drilling systems, directional drilling systems, and many other apparatuses. In an embodiment, a bearing assembly includes a plurality of superhard bearing elements distributed circumferentially about an axis. The thrust-bearing assembly further includes a support ring having the plurality of superhard bearing elements mounted thereto. The support ring includes at least one thermal-warping-reducing feature configured to reduce a radial moment, compared to if the at least one thermal-warping-reducing feature were absent from the support ring, which is thermally induced in the support ring when the support ring and the plurality of superhard bearing elements are exposed to operational temperature conditions.

A sliding sleeve opening tool includes an engaging element, a ball seat and a guiding head connected in sequence, as disclosed herein. The engaging element includes at least two elastic pawls uniformly disposed in a circumferential direction and at least one engaging part disposed on an external circumferential surface of an elastic pawl, and the engaging element is further provided with a first fluid channel which runs through the engaging element. The ball seat is provided with a second fluid channel which runs through the ball seat, and within the second fluid channel a taper hole section for bearing a sealing ball is disposed, the second fluid channel being in communication with the first fluid channel. The guiding head is provided with a third fluid channel which runs through the guiding head, and the third fluid channel is in communication with the second fluid channel. The sliding sleeve opening tool has at least one of the pushing function, the fishing function, the pushing assistance function, the mud scraping function and the sealing function.

Embodiments of the invention relate to polycrystalline diamond compacts (“PDCs”) and methods of fabricating such PDCs. In an embodiment, a PDC includes a substrate and a preformed polycrystalline diamond table including an interfacial surface bonded to the substrate and an opposing working surface. The preformed polycrystalline diamond table includes a proximal region extending from the interfacial surface to an intermediate location within the preformed polycrystalline diamond table that includes a metallic infiltrant infiltrated from the substrate, and a distal region extending from the working surface to the intermediate location that is substantially free of the metallic infiltrant. A boundary exists between the proximal and distal regions that has a nonplanar irregular profile characteristic of the metallic infiltrant having been infiltrated into the preformed polycrystalline diamond table.

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.

The bearing provides an outer ring and an inner ring capable of rotating concentrically relative to one another. At least one of the inner and outer rings are split into a plurality of successive circumferential ring segments. Each pair of adjacent successive ring segments of the split-ring is secured together with at least one fixing plate. The fixing plate is disposed inside a first groove disposed on one of the ring segments and a second groove 38 disposed on the other ring segment. The fixing plate is set back or flush with at least the surface of each of the ring segments from which the first or second groove is formed.

Embodiments disclosed herein relate to bearing apparatuses including a bearing assembly having a continuous superhard bearing element including a continuous superhard bearing surface and a tilting pad bearing assembly. The disclosed bearing apparatuses may be employed in pumps, turbines or other mechanical systems. In an embodiment, the bearing apparatus includes a first and second bearing assembly. The first bearing assembly includes a first support ring and a plurality of tilting pads. Each tilting pad is tilted and/or tiltably secured relative to the first support ring. The second bearing assembly includes a continuous superhard bearing element. The continuous superhard bearing element includes a continuous superhard bearing surface facing the plurality of tilting pads and exhibits a maximum lateral width greater than about 2 inches.

A clamping assembly may include a split-ring device and bearing for coupling to a driveshaft. The split-ring device may comprise split-ring shells having protrusions on an interior radial surface for positioning in grooves adjacent to radial protrusions on the driveshaft. In some aspects, the split-ring shells may include tabs corresponding to cavities on a first bearing for coupling the split-ring shell to the first bearing. In other aspects, the split-ring shells may be sized to create one or more gaps when positioned on the driveshaft. The first bearing may include one or more corresponding tabs for positioning in the one or more gaps created by the split-ring shells. A second bearing may be threadably coupled to the first bearing to suppress the axial and rotational movement of the clamping assembly separate from the driveshaft.

A thrust bearing includes a first axial end washer defining thereon a first race, a second axial end washer defining thereon a second race, a one-piece, radially-inner washer having a first axial end engaged with the first axial end washer and having a second axial end defining thereon a third race, and a one-piece, radially-outer washer having a first axial end defining thereon a fourth race and having a second axial end engaged with the second axial end washer. A first set of tapered rolling elements is supported between the first race and the fourth race and a second set of tapered rolling elements is supported between the second race and the third race. The first and second sets of tapered rolling elements are both axially and radially offset from one another.