Systems are provided for an air compressor system. In one example, a system includes a housing, a piston arranged in the housing, and a crankshaft arranged in the housing, the crankshaft coupled to a connecting rod of the piston, and the crankshaft forces the piston to oscillate from a first end of the housing to a second end, the piston pressurizing air in the housing to a first pressure at the first end and to a second pressure at the second end, the second pressure greater than the first.

A reciprocating compressor-expander according to the present invention comprises a cylinder, a piston, a crankshaft connected to the piston, a first valve for a low pressure compressible fluid, a second valve for a high pressure compressible fluid, and a valve drive mechanism for driving the first valve and the second respectively such that, during a compression process, the low-pressure compressible fluid is sucked into the cylinder from the first valve in synchronization with the rotation of the crankshaft and the high-pressure compressible fluid compressed in the cylinder is discharged from the second valve, and that, during an expansion process, the high-pressure compressive fluid is introduced from the second valve into the cylinder, and the low-pressure compressible fluid expanded in the cylinder is discharged from the first valve.

A hydraulic fracturing pump includes a power end with a plurality of torsion tubes extending between sides of a crankcase housing in which a crankshaft is rotatably mounted. The crankshaft is coupled by piston arms to crossheads disposed to reciprocate along crosshead axes that are perpendicular to the crankshaft. Disposed within the crankcase housing are a plurality of ribs generally perpendicular to the crankshaft and extending from the base of the crankshaft housing to an upper surface of the crankshaft housing. The torsion tubes are generally adjacent the upper surface of the crankcase housing and pass perpendicularly through each of the plurality of ribs and are attached to the ribs to provide rigidity to the power end.

A hydraulic engine with hydraulic pumps that moves the oil filled in the body thereof through the hydraulic pumps to allow rotational load bodies to be driven by means of the reciprocation of pistons, thereby obtaining a rotational force required for driving, includes: a power supply adapted to supply power to a driving part and to charge the power generated from rotational load bodies through the driving of a power driving part; the driving part driven through the power supplied from the power supply; a pair of hydraulic pumps adapted to pump a fluid through the rotation of the driving part; and the power driving part adapted to generate a driving force through the reciprocation of a driving piston.

A bull gear is provided for a reciprocating pump. The bull gear includes a hub extending around an axis of rotation of the bull gear. The bull gear includes a rim having a plurality of helical gear teeth extending along a circumference of the rim. The rim extends a width along the axis of rotation from a first side portion to a second side portion that is opposite the first side portion. The bull gear includes a web connecting the hub to the rim. The web extends a radial length from the first side portion of the rim to the hub.

A compressor includes a casing, a motor, a cylinder block including a cylinder, and a piston. The motor include a stator and a rotor located outside the stator, a rotary shaft coupled to the rotor, and a rotor frame that accommodates the rotor and the rotary shaft and that is configured to rotate together with the rotor and transmit rotational force of the rotor to the rotary shaft. The rotary shaft includes an eccentric part configured to rotate based on the rotational force of the rotor and located at a position offset from a rotational axis of the rotary shaft. The piston is coupled to the rotary shaft and configured to reciprocate in the cylinder based on rotation of the eccentric part. The rotor frame has a mass distribution configured to compensate an unbalance force generated by movement of at least one of the piston or the eccentric part.

A crankshaft, an inverter compressor and a refrigeration device are provided. The crankshaft has a main shaft, a crank, and a crank shaft at an end of the main shaft through the crank. The main shaft has an oil suction inner chamber, and an oil distribution channel penetrating the crank shaft. An outer wall surface of the main shaft has a first spiral oil groove and a second spiral oil groove. One end of each of the first spiral oil groove and a second spiral oil groove is in communication with the oil suction inner chamber. Another end of the first spiral oil groove and another end of the second spiral oil groove are formed as a first hole channel and a second hole channel in communication with the oil distribution channel, respectively.

An electric drive hydraulic fracturing pump system includes one or more electric motors, with each electric motor electrically coupled to a dedicated dual inverter to control operation of the motor. A plurality of electric motors may be coupled to each end of a pump crankshaft and configured to provide rotational power to the power end of a hydraulic fracturing pump through a planetary gearset coupled to each end of the crankshaft. A hydraulic cooling circuit having a first and second cooling systems may be used to regulate the temperature of the electric motors and dual inverters.

A hose for a reciprocating pump, the hose comprising: a first end and a second end separated by a length (L) along a centerline of the hose, wherein the first end reciprocates with a reciprocating element of the reciprocating pump during operation of the reciprocating pump; an inner surface and an outer surface separated by a thickness; and a variable bend radius wherein a bend radius of a first section of the hose is different from a bend radius of at least one second section of the hose, such that, during operation of the reciprocating pump, a stress on the first end of the hose, the second end of the hose, or both the first end of the hose and the second end of the hose is reduced relative to that of a hose that does not contain the variable bend radius.

An electrical submersible well pump assembly has first and second permanent magnet motors. The first motor drive shaft is connected to a coupling that has internal splines for receiving an externally splined end of the second motor drive shaft. Alignment devices rotationally align magnetic poles of the first drive shaft with the magnetic poles of the second drive shaft prior to securing the housings of the first and second motors together. The alignment devices may be a coupling irregularity in the internal splines that is at a controlled orientation relative to the magnetic poles of the first shaft and a shaft irregularity in the external splines that prevents the second drive shaft from fully engaging the coupling unless the shaft irregularity is in a specified rotational position relative to the coupling irregularity.