Embodiments are directed toward an engine. In some embodiments, the engine includes a water pump and a balancer shaft. In some embodiments, the water pump has a plain bearing. In some embodiments, plain bearing is supplied with pressurized oil. In some embodiments, the balancer shaft drives the water pump as well as cam shafts.

The provided is a bearing device for a crankshaft of an internal combustion engine including: a crankshaft having a plurality of journal portions; main bearings for supporting the crankshaft; and a bearing housing, wherein a range in which the oil groove of the upper-side halved bearing of the second main bearing is formed in the circumferential direction includes at least a range of a circumferential angle of 20° within the ±45° region, a circumferential end portion of the oil groove on a rotationally forward side communicates with the crush relief at a minimum, and is open to a circumferential end face at a maximum, and a circumferential end portion of the oil groove on the rotationally backward side of the journal portion is positioned on a circumferential center portion side of the upper-side halved bearing from a circumferential end face of the upper-side halved bearing.

Lubricating oil has a kinematic viscosity in a range of 1 mm.sup.2/S to 7 mm.sup.2/S at 40° C., has a mass average molecular weight in a range of 150 to 400, and contains 0.5% by mass or more of a high molecular weight component. The high molecular weight component has a mass molecular weight of greater than or equal to 500. A crankshaft serving as a shaft part of a compression element includes a main shaft that includes a sliding surface. In a case where the sliding surface is a single sliding surface, a length of the single sliding surface in an axial direction is a single sliding length L, whereas in a case where the sliding surface is divided into a plurality of sliding surfaces, a length of one of the sliding surfaces in the axial direction, the one sliding surface having a least length in the axial direction among the plurality of sliding surfaces, is the single sliding length L, and a ratio L/D of the single sliding length L to an external diameter D of the main shaft is less than or equal to 2.0.

Systems and methods are described for a reciprocating mechanism. The system includes at least one axially translating y-axis component configured to reciprocate substantially along a y-axis with a reciprocating motion of a piston assembly relative to a base. The system also includes at least one x-axis component slidingly coupled via at least one bearing assembly to and translating with the at least one y-axis component along the y-axis. The at least one x-axis component is configured to reciprocate substantially perpendicularly to the y-axis relative to the at least one y-axis component, and includes an orbital output component and an orbital linking component disposed substantially concentric with the orbital output component. The system also includes a stationary output component rotatably attached to the base in a direction that is substantially perpendicular to both the x-axis and y-axis, and a stationary linking component rotatably attached to the base in a direction that is substantially concentric with the stationary output component.

An internal combustion engine, including a pair of opposed pistons, a pair of opposed cylinders, and an output shaft, wherein each of the pistons is arranged for reciprocating motion within a respective one of the cylinders, driven by combustion, and the pistons are coupled to the output shaft by a coupling such that said reciprocating motion of the pistons drives rotation of the output shaft, wherein the coupling includes a connecting rod coupled to the opposed pistons, and the coupling further includes a crankshaft rotatably mounted within a slider bearing, the slider bearing being formed of separable parts and having unitary sides for sliding contact within the connecting rod.

An internal combustion engine is provided, which includes an engine body provided with a cylinder and a piston reciprocatably accommodated in the cylinder, a crankshaft that converts reciprocating movement of the piston into rotational movement, and a bearing member pivotally supporting the crankshaft via lubricating oil. The crankshaft includes a crank journal pivotally supported by the bearing member, and a counterweight extending radially outward from an axial end part of the crank journal. The crank journal has a recess formed in a part thereof corresponding to the extended position of the counterweight, the recess being depressed radially inwardly. The recess is deeper at the axial end part of the crank journal than an axial center part.

A skid for supporting a reciprocating pump assembly, the reciprocating pump assembly including a power end frame assembly having a pair of end plate segments and a plurality of middle plate segments disposed between the end plate segments. The end plate segments each have at least a pair of feet and the middle plate segments each having at least one foot. The skid includes a base and a plurality of pads extending from the base. At least a portion of the plurality of pads correspond to the end plate segment feet and at least another portion of the plurality of pads correspond to the at least one foot of each middle plate segment.

A sliding bearing that is disposed in a cylinder block and supports a journal portion of a crankshaft, including: a semi-annular first split bearing having a first circumferential end surface; and a semi-annular second split bearing having a second circumferential end surface. The first and second circumferential end surfaces contact each other, the first split bearing has a same outer diameter as an outer diameter of the second split bearing, the second split bearing has a thickness at a second circumferentially central position that is greater than a thickness of the first split bearing at a first circumferentially central position, the thickness of the first split bearing is decreased from the first circumferentially central position toward the first circumferential end surface, the thickness of the second split bearing is decreased from the second circumferentially central position toward the second circumferential end surface.

A sliding bearing that is disposed in a cylinder block and supports a journal portion of a crankshaft, including: a semi-annular first split bearing having a first circumferential end surface; and a semi-annular second split bearing having a second circumferential end surface. The first and second circumferential end surfaces contact each other, the first split bearing has a same outer diameter as an outer diameter of the second split bearing, the second split bearing has a thickness at a second circumferentially central position that is greater than a thickness of the first split bearing at a first circumferentially central position, the thickness of the first split bearing is decreased from the first circumferentially central position toward the first circumferential end surface, the thickness of the second split bearing is decreased from the second circumferentially central position toward the second circumferential end surface.

A gearbox is coupled to a power end housing of a reciprocating pump, where the gearbox includes at least one support member having a first end securely affixed to the gearbox, and the at least one support member having a second end securely affixed to an immobile part of the reciprocating pump for supporting the gearbox and resisting movement of the gearbox relative to the reciprocating pump.