A method for estimating the temperature of a stator coil of a magnetic suspension bearing of a rotor that is connected by connection wires to circuits for servo-controlling the position of the rotor includes the following steps: measuring the electric voltage at the terminals of the connection wires of the stator coil; measuring the intensity of the current passing through the stator coil; estimating the electric resistance of the stator coil and of the connection wires on the basis of an adaptive filter, the measured electric voltage and the intensity of the measured current; and estimating the temperature of the coil on the basis of the value of the estimated resistance.

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.

A self-aligning mud pump apparatus is provided. In one embodiment, the mud pump includes a rotatable crankshaft, a crosshead, a crosshead guide, and a hub disposed in a housing. The hub is disposed on the crankshaft and is operable to convert rotating motion of the crankshaft to reciprocating motion of the crosshead within the crosshead guide. The hub is coupled to the crosshead via a connecting rod, which is connected the crosshead such that the connecting rod has five degrees of freedom with respect to the crosshead guide. The mud pump may also or instead include a piston coupled to the crosshead with five degrees of freedom between the piston and the crosshead. Additional systems, devices, and methods are also disclosed.

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.

A crosshead part for drilling pumps includes an upper guide plate, a lower guide plate and a crosshead, wherein the crosshead reciprocates in a straight line between the upper guide plate and the lower guide plate; at least one of the upper and lower guide plates has an oil inlet for introducing external lubricating oil between the at least one of the upper and lower guide plates and an arc surface of the crosshead. A crosshead system for drilling pumps includes a lubricating pipeline system and the crosshead part. The lubricating pipeline system includes a main pipeline and N branch pipelines. A drilling pump includes the crosshead part or the crosshead system.

A pivot cradle bearing (1) having a pivoting element (2) which is mounted to pivot in a housing (3) is provided in which an inner bearing shell (7), on which rolling bodies (4) are rolling, is held on the pivoting element (2). The inner bearing shell (7) is held by rivets (10) in a form-fitting manner on the pivoting element (2) in the circumferential direction of the bearing shell (7).

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 sintered bearing is made of a sintered compact containing nickel silver (Cu—Ni—Zn) as a base. In the sintered bearing, P is not added in the sintered compact. Alternatively, a content of P in the sintered compact is less than 0.05 mass % in terms of mass ratio to a total mass. Consequently, crystal grains constituting the sintered compact can be micronized. In particular, in the sintered bearing, an average crystal particle diameter of the crystal grains constituting the sintered compact is 20 μm or less. Consequently, the mechanical strength and the vibration resisting properties can be improved, and the rotation shaft can be prevented from being damaged.

A crankshaft simulation device includes: a fixed shaft in which a through hole extending in the axial direction of the fixed shaft is provided; a wedge-shaped rod which is movable in the through hole under an external force, and the first end of the wedge-shaped rod is extendable from the first axial end of the fixed shaft, the second end of the wedge-shaped rod is extendable from the second axial end of the fixed shaft, and the first end of the wedge-shaped rod is provided with an inclined surface so that the first end of the wedge-shaped rod is wedge-shaped; a support rod extending from the first axial end of the fixed shaft in the axial direction of the fixed shaft; a movable shaft in which a flat through hole is provided, and the support rod is inserted into the flat through hole, and the size of the flat through hole in the radial direction of the movable shaft is configured to allow the movable shaft to be shifted in the radial direction of the movable shaft, and the flat through hole is configured to allow the first end of the wedge-shaped rod to be inserted into the flat through hole before the movable shaft is shifted in the radial direction of the movable shaft; and a spring pushing the movable shaft outwards in the radial direction of the movable shaft.