A pump system includes a pump assembly and a pump controller. The pump assembly includes a housing defining a first volume and a second volume separated by a divider, a first piston dividing the first volume into a first chamber and a second chamber, a second piston dividing the second volume into a third chamber and a fourth chamber, and a piston rod coupling the first piston and the second piston such that a movement of the first piston causes an equal movement of the second piston. The pump controller is configured to alternately supply a first fluid to the second chamber and the fourth chamber to cause the first piston and the second piston to reciprocate within the housing.

A gas compressor includes an incompressible fluid source for storing an incompressible fluid. A rotary shaft is coupled to the incompressible fluid source. Operation of the rotary shaft draws the incompressible fluid up or down the rotary shaft. A piston chamber is coupled to each piston in a set of pistons. The incompressible fluid is delivered to the first piston by a controlled fluid valve assembly, to drive the first piston. The centripetal force from the rotation of the rotary shaft and the force of incompressible fluid from an impeller drive the first piston to compress a gas in the piston chamber of the first piston. The incompressible fluid is released from the first piston, by the controlled fluid valve assembly. The incompressible fluid is alternately delivered to the second piston to drive the second piston and compress gas.

Methods and systems to provide compressed air via exhaust gases of an internal combustion engine are presented. In one example, a pump comprising two pistons is driven via engine exhaust gases. On piston within the pump moves in response to the exhaust gases while the other piston acts to compress air.

A hydraulically operated compressor has a fixed piston and a fixed compression or outer cylinder. A drive or intermediate cylinder is located between the piston and outer cylinder. A compression chamber is formed between the drive cylinder and the outer cylinder. Drive fluid is pumped into and released from an interior chamber in the drive cylinder to reciprocate the drive cylinder. The drive fluid also provides cooling to the interior of the compressor.

Methods and systems are provided for conducting a diagnostic routine of the fuel vapor system using pressure generated by raising or lowering a vehicle body element such as a hood or a trunk. In one example, by utilizing lift gate cylinders coupled to the hood or trunk, during raising a hood or trunk, the fuel vapor system may be evacuated and during lowering the hood or trunk, the fuel vapor system may be pressurized. A change in vacuum or higher pressure in the fuel vapor system may be monitored over a time period to detect any undesirable evaporative emissions from the fuel vapor system.

Systems are provided comprising at least one driving cylinder comprising a driving chamber and a driving piston within the driving chamber. The driving piston separates the driving chamber into a driving fluid zone for receiving a driving fluid and a buffer zone for receiving a buffer fluid. The driving piston is movable in the driving chamber by the driving fluid. The systems may also comprise a driven cylinder comprising a driven chamber and a driven piston moveable in the driven chamber. The driven piston is connected to and driven by the driving piston to move within the driven chamber. The driven chamber comprises an input port configured to receive a driven fluid at a first, lower pressure into the driven chamber and an output port configured to expel the driven fluid at a second, higher pressure from the driven chamber when the driven fluid is pressurized by the driven piston. The buffer fluid is different from the driving fluid and the driven fluid, and the buffer fluid in the buffer zone separates the driving fluid from the driven fluid.

A compressor and a method for conveying and compressing a fluid into a target system. The compressor has a first drive part having a first drive piston, a second drive part having a second drive piston and at least a first high-pressure part having a high-pressure piston. The first drive piston and the second drive piston are each able to be subjected to a drive fluid piston on alternate sides controlled via a first control unit. The first drive, the second drive piston and the high-pressure piston are jointly movable axially coupled via a piston rod arrangement. The second drive part is assigned a second control unit, which is arranged after the first control unit and via which the subjecting of the second drive piston to drive fluid is able to be activated.

A method and apparatus for gas compression and expansion that simultaneously serves as storage tank for the compressed gas, and heat exchanger for heat transfer to the environment to maintain near-isothermal conditions.

A closed dual-bladder wave energy system that is capable of capturing a continuous supply of energy derived from wave movements for nearshore implementations. Rather than employing an onshore bladder in communication with an offshore bladder, and rather than focusing on capturing more incremental potential energy derived from tidal movement, the system accomplishes continuous captures potential energy from waves via a dual-bladder system employed offshore. Fluid within the system translates between a first offshore bladder and a second offshore bladder based on a pressure differential between a crest and a trough of a wave external to the system. By utilizing compliant bladders, the system is capable of capturing energy even during inclement weather conditions without the risk of faults resulting from strong waves. As such, the system provides for the efficient and effective capture of potential energy from waves in any weather condition and in any water environment that experiences waves.

Refrigeration apparatus (1) having a closed circuit (C) in which a flow rate (P) of coolant circulates, said closed circuit comprising at least one main branch (M) provided with at least one main compressor (2), at least one cooling device (3) to cool said coolant, expansion means (4) to expand the coolant and at least one evaporator (5), said closed circuit further comprising at least one secondary economizer branch (100) for at least one fraction of flow rate (X1) of said coolant, wherein the inlet section (100a) of said at least one first secondary economizer branch (100) is arranged in a length (101) of said closed circuit (C) comprised between said cooling device (3) and said expansion means (4) and the outlet section (100b) of said at least one secondary economizer branch (100) is arranged in proximity of the suction of said main compressor (2), said main branch (M) further comprises at least one reciprocating compressor (6) arranged between said evaporator and said main compressor. Said at least one secondary economizer branch comprises at least one control device for diverting at least one portion (X2) of said fraction (X1) of coolant coming from said secondary economizer branch (100) to drive the reciprocating compressor.