Both conflicting functions of sealing and lubrication of sliding faces are made compatible over an entire period from the time of startup through the time of steady operation. A pair of sliding parts that relatively slide on each other is provided, one of the sliding parts being a stationary-side seal ring, the other of the sliding parts being a rotating-side seal ring, the seal rings each having a sliding face S formed radially for sealing sealed fluid from leaking, at least one of the sliding faces S being provided with fluid introduction grooves 10 configured to communicate with a first peripheral edge of the sliding face S and not to communicate with a second peripheral edge, and being provided with dynamic pressure generation grooves configured to communicate with the second peripheral edge of the sliding face S and not to communicate with the first peripheral edge.

An electric submersible pump assembly with integral heat exchanger, high-speed self-aligning bearings, and dual bearing thrust chamber is described. The described pump assembly, modules, and components may be used for operating an electric submersible pump at high speeds as well as over a wide range of speeds and flowrates without replacing downhole equipment. The described pump assembly may be shorter than comparable pump assemblies and may be assembled offsite, thereby leading to faster and easier installation with less down time. By operating over a wide range of speeds, the disclosed pump assembly allows the operator to reduce overall inventory, reduce down time for the well, and avoid other complications associated with replacing a pump assembly or other downhole components.

Provided is a semi-cylindrical shaped half bearing. The half bearing has an inner surface forming a sliding surface. The sliding surface includes a plurality of recesses. Each recess has a smooth recess surface recessed from the sliding surface toward an outer diameter side of the half bearing. The recess surface forms a convex curve toward the outer diameter side of the half bearing in a cross-sectional view in any direction perpendicular to the sliding surface. The recess surface includes a plurality of circumferential grooves. The circumferential grooves are recessed from the recess surface toward the outer diameter side of the half bearing. The circumferential grooves extend along a circumferential direction of the half bearing so that smooth surfaces and the circumferential grooves are alternately arranged on the recess surface.

Provided is a bearing structure, including: a thrust bearing surface having a through hole for allowing a shaft to be inserted therethrough; a plurality of land portions, which are formed on the thrust bearing surface, and are separated apart from each other in a rotation direction of the shaft; a tapered portion, which is formed between the plurality of land portions on the thrust bearing surface, and has a projection height in an insertion direction of the shaft which becomes higher toward a forward side in the rotation direction; and a thrust groove, which is formed in the tapered portion, and extends from the through hole to a radially inner side of an outer peripheral end of the tapered portion.

Provided is a semi-annular shaped half thrust bearing. The half thrust bearing has a sliding surface and a back surface opposite to the sliding surface. The sliding surface includes a plurality of recesses. Each recess has a recess surface recessed from the sliding surface toward the back surface. The recess surface is convex toward the back surface in cross-sectional view in a center line direction of the half thrust bearing. The recess surface includes a plurality of grooves. The grooves are recessed from the recess surface toward the back surface. The grooves extend in the center line direction so that smooth surfaces and the grooves are alternately arranged on the recess surface in a horizontal direction of the half thrust bearing.

A thrust washer according to an embodiment has an annular washer body having a first thrust surface and a second thrust surface that receive a thrust load, and a tapered portion formed on at least one of the first thrust surface and the second thrust surface, and the washer body has a waviness larger than a difference in height of the tapered portion in a direction perpendicular to the thrust surface.

A crankshaft including a plurality of journals, a plurality of crank pins; and a plurality of crank webs connecting select ones of the plurality of journals with select ones of the plurality of crank pins. One or more of the plurality of crank webs includes at least one radially outwardly exposed surface a plurality of cooling features formed thereon.

In a pair of sliding parts having sliding faces S that slide with respect to each other, at least one of the sliding faces S has a one-side peripheral edge (4a) and an other-side peripheral edge (4b) and includes: fluid introduction grooves (12) each of which has one end communicating with the other-side peripheral edge (4b), dynamic pressure generation grooves (11) each of which has one end communicating with the other-side peripheral edge (4b) and the other end being surrounded by a land portion, and a release groove (13) provided in the land portion, the release groove (13) communicating with the fluid introduction grooves (12). With the sliding parts, not only a liquid such as oil but also an oil mist serving as a mixture of oil and air can be sealed as a sealed fluid, and generation of oil mist itself can be reduced.

A hydrodynamic bearing contains a body of which an inner surface forms a cavity arranged to accommodate and surround a rotary shaft. The cavity has a plurality of pads installed on the inner surface so as to support and guide the rotary shaft in rotation in a direction of rotation w from upstream to downstream. Each pad has an upper surface of which one portion, referred to as the active surface, acts as a sliding surface for the rotary shaft. The bearing having at least one pad included in an active angular sector of the bearing and at least one pad included in a passive angular sector of the bearing such that the active surface of each pad of the passive angular sector is lower than the active surface of each of the pads of the active angular sector.

An electric submersible pump assembly with integral heat exchanger, high-speed self-aligning bearings, and dual bearing thrust chamber is described. The described pump assembly, modules, and components may be used for operating an electric submersible pump at high speeds as well as over a wide range of speeds and flowrates without replacing downhole equipment. The described pump assembly may be shorter than comparable pump assemblies and may be assembled offsite, thereby leading to faster and easier installation with less down time. By operating over a wide range of speeds, the disclosed pump assembly allows the operator to reduce overall inventory, reduce down time for the well, and avoid other complications associated with replacing a pump assembly or other downhole components.