A piston type compressor has a main housing including a cylinder housing. The cylinder housing has a central bore for receiving a shaft therein through a first surface thereof and a plurality of bores configured for receiving a plurality of pistons therein through the first surface thereof. An inlet is configured for conveying a primary fluid to the plurality of bores. An outlet is configured for conveying the primary fluid from the plurality of bores. A plurality of passages is separate from the inlet and the outlet. Each of the plurality of passages is formed in the main housing and is configured for conveying a supplemental fluid to one of the plurality of bores.

A swash plate compressor including: a housing; a rotating shaft rotatably mounted to the housing; a swash plate accommodated in a crank chamber of the housing and rotating with the rotating shaft; a piston forming a compression chamber with the housing and interlocking with the swash plate to reciprocate; a discharge flow path guiding a refrigerant of the crank chamber to a suction chamber of the housing wherein an inclination angle of the swash plate is adjusted; and a discharge flow path control valve having a valve chamber provided in the discharge flow path and a valve core reciprocating inside the valve chamber, and the valve core includes: a first communication path constantly communicating the discharge flow path; and a second communication path communicating the discharge flow path when differential pressure between pressure of the crank chamber and pressure of the suction chamber is within a certain pressure range.

A piston type compressor has a main housing including a cylinder housing. The cylinder housing has a central bore for receiving a shaft therein through a first surface thereof and a plurality of bores configured for receiving a plurality of pistons therein through the first surface thereof. An inlet is configured for conveying a primary fluid to the plurality of bores. An outlet is configured for conveying the primary fluid from the plurality of bores. A plurality of passages is separate from the inlet and the outlet. Each of the plurality of passages is formed in the main housing and is configured for conveying a supplemental fluid to one of the plurality of bores.

A piston compressor includes a housing, a drive shaft, a fixed swash plate, a plurality of pistons, a movable body, and a control valve. The housing includes a cylinder block having a plurality of cylinder bores and a plurality of first communication passages. The movable body has a second communication passage that intermittently communicates with each of the first communication passages by rotation of the drive shaft. A flow rate of refrigerant discharged from a compression chamber into a discharge chamber changes according to a position of the movable body in a direction of an axis of the drive shaft. The control valve is configured to control a control pressure. The first communication passages are connected to the second communication passage by the movable body and disconnected from the second communication passage by the drive shaft.

A submersible pump assembly for transference of a fluid medium with low viscosity is disclosed. In one embodiment, the submersible pump assembly includes a cylinder block having cylinders and pistons. A drive shaft is rotatably supported in the cylinder block and coupled to a drive unit. An inclined leading plate is coupled to the pistons and the drive shaft such that the pistons are configured to be axially driven in a reciprocating motion within the cylinders upon rotation of the inclined leading plate. A suction chamber and a pressure chamber are each located in fluid communication with the cylinders. In one operational mode, the fluid medium is transferred from the suction chamber to the pressure chamber during the reciprocating motion of the pistons, when the pistons are active. In another operational mode, the fluid medium is circulated through the suction chamber.

A variable displacement swash plate type compressor includes a first and a second valve body, and a suction and a bleed window. An open degree of the suction window is minimized by the first valve body and an open degree of the bleed window is maximized by the second valve body when a suction pressure is lower than a predetermined suction pressure and a crank chamber pressure is higher than a control pressure. The open degree of the suction window is increased and the open degree of the bleed window is maximized when the suction pressure is higher than the predetermined suction pressure and the crank chamber pressure is higher than the control pressure. The open degree of the suction window and the open degree of the bleed window are decreased when the crank chamber pressure is lower than the control pressure.

A boosting device is provided with a drive unit which is driven under the action of energization, and a boosting mechanism which is connected to the drive unit and which boosts and outputs a pressurized fluid. The boosting mechanism comprises a rotating body which is connected to a drive shaft of a drive source and includes a slope portion, and four pistons opposing the rotating body and disposed moveably in an axial direction. The pistons are sequentially and continuously pushed in the axial direction by means of the slope portion of the rotating body, whereby the pressurized fluid is compressed and boosted in a boosting chamber. The pressurized fluid that has been boosted in the boosting chamber is discharged out of an output port through a discharge passageway when an exhaust check valve is opened.

A piston compressor includes a housing, a drive shaft, a fixed swash plate, a plurality of pistons, a movable body, and a control valve. The housing includes a cylinder block having a plurality of cylinder bores and a plurality of first communication passages. The movable body has a second communication passage that intermittently communicates with each of the first communication passages by rotation of the drive shaft. A flow rate of refrigerant discharged from a compression chamber into a discharge chamber changes according to a position of the movable body in a direction of an axis of the drive shaft. The control valve is configured to control a control pressure. The first communication passages are connected to the second communication passage by the movable body and disconnected from the second communication passage by the drive shaft.

A variable displacement swash plate type compressor includes a first and a second valve body, and a suction and a bleed window. An open degree of the suction window is minimized by the first valve body and an open degree of the bleed window is maximized by the second valve body when a suction pressure is lower than a predetermined suction pressure and a crank chamber pressure is higher than a control pressure. The open degree of the suction window is increased and the open degree of the bleed window is maximized when the suction pressure is higher than the predetermined suction pressure and the crank chamber pressure is higher than the control pressure. The open degree of the suction window and the open degree of the bleed window are decreased when the crank chamber pressure is lower than the control pressure.

A two-way flow rotary valve for a reversible compressor is disclosed. The two-way flow rotary valve comprises a tubular member with a first end and a second end. Two or more low friction face seals are disposed around the tubular member between the first end and the second end and a central section is disposed between the two or more low friction face seals. The two or more low friction face seals allow the central section to rotate within a substantially cylindrical receiver of a cylinder head. A gas port extends through the tubular member and is configured to allow the rotary valve to selectively exchange gas with a cylinder (when used as a compressor and when used as an air motor).