Systems, methods and devices are described providing a selective hydraulic or electrically powered prime mover that is a bi-directional power unit system, including movement within a device used to compress and/or expand a fluid and provide fluid movement. The use of a hydraulic power unit is involved and comprises at least a pump or other fluid moving device, a first set of selective control valves delivering pressurized fluid to the device(s), and a second set of selective control valves returning unpressurized fluid from the device(s), a reservoir comprising a compensator tank, a port for operation at ambient pressure, and a pressure measuring device measuring ambient pressure allowing for unbalanced flow to and from the device as well as thermal expansion or compression. The use of a multiport and in some cases a swashplate pump that incorporates the features and functions of several valves for the system is also described.

Systems, methods and devices are described providing a selective hydraulic or electrically powered prime mover that is a bi-directional power unit system, including movement within a device used to compress and/or expand a fluid and provide fluid movement. The use of a hydraulic power unit is involved and comprises at least a pump or other fluid moving device, a first set of selective control valves delivering pressurized fluid to the device(s), and a second set of selective control valves returning unpressurized fluid from the device(s), a reservoir comprising a compensator tank, a port for operation at ambient pressure, and a pressure measuring device measuring ambient pressure allowing for unbalanced flow to and from the device as well as thermal expansion or compression. The use of a multiport and in some cases a swashplate pump that incorporates the features and functions of several valves for the system is also described.

A hydraulic control device for a hydraulic actuation machine including a main oil pump configured to supply oil to the hydraulic actuation machine, a sub oil pump configured to temporarily supply oil to the hydraulic actuation machine based on a drive request so as to compensate for an oil shortfall when supply of oil from the main oil pump to the hydraulic actuation machine is stopped or insufficient, and a drive unit configured to drive the sub oil pump, wherein when an elapsed time elapsed from a time point when the sub oil pump is driven reaches a predetermined time, the hydraulic control device generates an air discharge command for discharging air accumulated in the sub oil pump and outputs the air discharge command to the drive unit, and the drive unit drives the sub oil pump to discharge the air accumulated in the sub oil pump based on the output air discharge command.

A hydraulic control device for a hydraulic actuation machine including a main oil pump configured to supply oil to the hydraulic actuation machine, a sub oil pump configured to temporarily supply oil to the hydraulic actuation machine based on a drive request so as to compensate for an oil shortfall when supply of oil from the main oil pump to the hydraulic actuation machine is stopped or insufficient, and a drive unit configured to drive the sub oil pump, wherein when an elapsed time elapsed from a time point when the sub oil pump is driven reaches a predetermined time, the hydraulic control device generates an air discharge command for discharging air accumulated in the sub oil pump and outputs the air discharge command to the drive unit, and the drive unit drives the sub oil pump to discharge the air accumulated in the sub oil pump based on the output air discharge command.

Provided is a hydraulic drive device that is provided in a work device and with which it is possible to obtain a high energy-saving effect with a low-cost configuration while being equipped with a plurality of hydraulic actuators. The hydraulic drive device is provided with: first and second actuator groups; closed circuits connected to hydraulic actuators included in the first actuator group; a pump section including closed circuit pumps; open circuits which include a plurality of variable throttle valves for changing the flow rate of working fluid supplied from a hydraulic pump included in the pump section to a hydraulic actuator; and circuit switching sections having a first state in which the closed circuits are opened and the opened circuits are blocked, and a second state in which the closed circuits are blocked and the open circuits are opened.

A pumping system deployed in a wellbore has a motor, a pump driven by the motor, and a volumetric compensator connected to the motor to accommodate the expansion and contraction of fluids contained within the motor. The volumetric compensator has a head connected to the motor, a base that includes a fluid exchange port that extends to the wellbore, and a housing extending between the head and the base. The volumetric compensator further includes an inverted bellows assembly contained within the housing. The inverted bellows assembly includes a metal bellows that has an interior, an exterior, a proximal end and a distal end. The interior of the metal bellows is in fluid communication with the wellbore. The inverted bellows assembly may also include one or more guide rings connected to the exterior of the metal bellows. The guide rings are lubricated by the clean motor fluid surrounding the exterior of the metal bellows.

A pumping system deployed in a wellbore has a motor, a pump driven by the motor, and a volumetric compensator connected to the motor to accommodate the expansion and contraction of fluids contained within the motor. The volumetric compensator has a head connected to the motor, a base that includes a fluid exchange port that extends to the wellbore, and a housing extending between the head and the base. The volumetric compensator further includes an inverted bellows assembly contained within the housing. The inverted bellows assembly includes a metal bellows that has an interior, an exterior, a proximal end and a distal end. The interior of the metal bellows is in fluid communication with the wellbore. The inverted bellows assembly may also include one or more guide rings connected to the exterior of the metal bellows. The guide rings are lubricated by the clean motor fluid surrounding the exterior of the metal bellows.

Systems, methods and devices are described providing a selective hydraulic or electrically powered prime mover that is a bi-directional power unit system, including movement within a device used to compress and/or expand a fluid and provide fluid movement. The use of a hydraulic power unit is involved and comprises at least a pump or other fluid moving device, a first set of selective control valves delivering pressurized fluid to the device(s), and a second set of selective control valves returning unpressurized fluid from the device(s), a reservoir comprising a compensator tank, a port for operation at ambient pressure, and a pressure measuring device measuring ambient pressure allowing for unbalanced flow to and from the device as well as thermal expansion or compression. The use of a multiport and in some cases a swashplate pump that incorporates the features and functions of several valves for the system is also described.

Systems, methods and devices are described providing a selective hydraulic or electrically powered prime mover that is a bi-directional power unit system, including movement within a device used to compress and/or expand a fluid and provide fluid movement. The use of a hydraulic power unit is involved and comprises at least a pump or other fluid moving device, a first set of selective control valves delivering pressurized fluid to the device(s), and a second set of selective control valves returning unpressurized fluid from the device(s), a reservoir comprising a compensator tank, a port for operation at ambient pressure, and a pressure measuring device measuring ambient pressure allowing for unbalanced flow to and from the device as well as thermal expansion or compression. The use of a multiport and in some cases a swashplate pump that incorporates the features and functions of several valves for the system is also described.

A piston accommodated in an internal space of a cylinder and forming a pair of pressure chambers together with the cylinder, the piston being configured to move relative to the cylinder; a first actuator connected to one pair of pressure chambers; a second actuator connected to the other of the pair of pressure chambers; a position detector configured to detect a position of the piston relative to the cylinder; a pressure detector configured to detect a pressure of one pair of pressure chambers; and a controller configured to control the first actuator and the second actuator. The controller controls one of the first actuator and the second actuator that the position detected by the position detector is made close to a target position and controls the other of the first actuator and the second actuator that the pressure detected by the pressure detector is made close to a target pressure.