An ultra-long stroke multi-cylinder reciprocating pump comprises a small gear, a large gear, a crankshaft, connecting rods, fixed racks, a frame, translation pinions, movable racks, clamps, piston rods, cylinder sleeves, pistons, suction valves, liquid discharging valves, guide rails, a prime motor, a coupling, and a small gear shaft. When the prime motor rotates, the small gear is meshed with the large gear to drive the crankshaft to rotate, an axial center of the translation pinion is driven by the connecting rod to move reciprocally, the translation pinion is meshed with the fixed rack and the movable rack simultaneously, and a distance of reciprocating motion of the movable rack is twice a distance of reciprocating motion of a rotation center of the translation pinion, so that an ultra-long stroke is realized.

A motor-hydraulic machine unit includes an electric motor, a hydraulic machine, and a connection body that has a planar connection surface which delimits first and second working connections. The first and second working connections are each in fluid exchange connection with the hydraulic machine via an assigned first fluid duct in the connection body. The electric motor and the hydraulic machine have a common axis of rotation which is arranged substantially parallel to the connection surface. The hydraulic machine and the electric motor are arranged on opposite sides of the connection body in the direction of the axis of rotation. The connection body is traversed by a drive aperture in the direction of the axis of rotation. The electric motor and the hydraulic machine are in rotary drive connection in a region of the drive aperture.

A motor-hydraulic machine unit includes an electric motor, a hydraulic machine, and a connection body that has a planar connection surface which delimits first and second working connections. The first and second working connections are each in fluid exchange connection with the hydraulic machine via an assigned first fluid duct in the connection body. The electric motor and the hydraulic machine have a common axis of rotation which is arranged substantially parallel to the connection surface. The hydraulic machine and the electric motor are arranged on opposite sides of the connection body in the direction of the axis of rotation. The connection body is traversed by a drive aperture in the direction of the axis of rotation. The electric motor and the hydraulic machine are in rotary drive connection in a region of the drive aperture.

An improved fracturing pump is provided. The pump is reconfigurable on site. The pump uses a bull gear/pinion drive arrangement that increases reliability and efficiency. Internal components of the pump may be varied to meet the requirements of a specific operation. The reconfiguration gives the user the ability to increase or decrease the horsepower of the pump. A closed loop oil feed system provides constant and reliable lubrication even under heavy loads. The sealing system is enhanced to reduce leaks and thermal stresses. The pump also has an improved frame and chassis to reduce NVH and enhance reliability.

An improved fracturing pump is provided. The pump is reconfigurable on site. The pump uses a bull gear/pinion drive arrangement that increases reliability and efficiency. Internal components of the pump may be varied to meet the requirements of a specific operation. The reconfiguration gives the user the ability to increase or decrease the horsepower of the pump. A closed loop oil feed system provides constant and reliable lubrication even under heavy loads. The sealing system is enhanced to reduce leaks and thermal stresses. The pump also has an improved frame and chassis to reduce NVH and enhance reliability.

A pumping system for fracking fluid is designed to provide nearly constant flow rate. The pumping system includes a set of linear actuator pumping units, each driven by an electric motor. Each pumping unit includes a first set of pumping chambers that expel fluid when the linear actuator is moving in a first direction and a second set of pumping chambers that expel fluid when the linear actuator is moving in an opposite direction. The speeds of the actuators are coordinated such that a total flow rate of the pumping system is substantially constant.

A rotatable piston assembly for a reciprocating piston type hydraulic machine includes a rotatable piston configured for a controlled rotation and configured to reciprocate within a cylinder bore of the reciprocating piston type hydraulic machine.

A rotatable piston assembly for a reciprocating piston type hydraulic machine includes a rotatable piston configured for a controlled rotation and configured to reciprocate within a cylinder bore of the reciprocating piston type hydraulic machine.

A pump system includes a pressure compensator and a speed compensator for controlling the displacement of a variable displacement pump having an inlet and an outlet. The variable displacement pump is driven by a drive shaft powered by an electric motor. The pressure compensator adjusts the displacement of the variable displacement pump based on a pump pressure at the pump outlet. The speed compensator adjusts a maximum magnitude of the displacement of the variable displacement pump based on a speed of the electric motor.

A pump system includes a pressure compensator and a speed compensator for controlling the displacement of a variable displacement pump having an inlet and an outlet. The variable displacement pump is driven by a drive shaft powered by an electric motor. The pressure compensator adjusts the displacement of the variable displacement pump based on a pump pressure at the pump outlet. The speed compensator adjusts a maximum magnitude of the displacement of the variable displacement pump based on a speed of the electric motor.