A scroll compressor is provided that may include a first back pressure unit that allows a refrigerant to flow from a first compression chamber to a back pressure chamber while blocking a reverse flow of the refrigerant, and a second back pressure unit that allows the refrigerant to flow from the back pressure chamber to a second compression chamber while blocking a reverse flow of the refrigerant. The first back pressure unit and the second back pressure unit may be spaced apart from each other in a direction that the compression chambers are formed. This may reduce pressure pulsation in the back pressure chamber. Also, leakage between compression chambers may be suppressed and simultaneously friction loss may be reduced by appropriately adjusting the pressure in the back pressure chamber. This is especially advantageous for enhancing compression efficiency under low load operating conditions (or in a low pressure ratio operation).

A system and method are presented for improved performance of gerotor compressors and expanders. Certain aspects of the disclosure reduce porting losses in a gerotor system. Other aspects of the disclosure provide for reduced deflection in lobes of an outer rotor of a gerotor system. Still other aspects of the disclosure provide for reduced leakage through tight gaps between components of a gerotor system.

A system and method are presented for improved performance of gerotor compressors and expanders. Certain aspects of the disclosure reduce porting losses in a gerotor system. Other aspects of the disclosure provide for reduced deflection in lobes of an outer rotor of a gerotor system. Still other aspects of the disclosure provide for reduced leakage through tight gaps between components of a gerotor system.

Provided is a back pressure regulating valve and an electric type of a scroll compressor with the same. A valve of an electric scroll compressor for regulating a back pressure includes a valve housing including a first housing 11, a second housing and a communicating passage 13 for connecting the first housing 11 to the second housing 12; and a piston 14 including a first piston 141 located within the first housing 11, a second piston located within the second housing 12 and a connecting rod 143 for connecting the first piston 141 to the second piston 142, wherein the piston 14 is configured to move up and down within the first and the second housing 11, 12.

The present invention relates to a pumping method in a pumping system (SP, SPP) comprising: a primary lubricated rotary vane vacuum pump (3) with a gas inlet port (2) connected to a vacuum chamber (1) and a gas outlet port (4) leading into a conduit (5) before coming out into the gas outlet (8) of the pumping system (SP, SPP), a non-return valve (6) positioned in the conduit (5) between the gas outlet port (4) and the gas outlet (8), and an ejector (7) connected in parallel to the non-return valve (6). According to this method, the primary lubricated rotary vane vacuum pump (3) is set into action in order to pump the gases contained in the vacuum chamber (1) through the gas outlet port (4). Simultaneously the ejector (7) is fed with working fluid, and the ejector (7) continues to be fed with working fluid all the while that the primary lubricated rotary vane vacuum pump (3) pumps the gases contained in the vacuum chamber (1) and/or all the while that the primary lubricated rotary vane vacuum pump (3) maintains a defined pressure in the vacuum chamber (1). The present invention also relates to a pumping system (SP, SPP) able to be used to implement this method.

Provided is a back pressure regulating valve and an electric type of a scroll compressor with the same. A valve of an electric scroll compressor for regulating a back pressure includes a valve housing including a first housing 11, a second housing and a communicating passage 13 for connecting the first housing 11 to the second housing 12; and a piston 14 including a first piston 141 located within the first housing 11, a second piston located within the second housing 12 and a connecting rod 143 for connecting the first piston 141 to the second piston 142, wherein the piston 14 is configured to move up and down within the first and the second housing 11, 12.

A fluid compressor system has a scavenge loss limiter that increases the efficiency of the fluid compressor system by reducing the compressed working fluid recirculated into the airend through a scavenge flow. The scavenge loss limiter includes a scavenge hole positioned at a discharge end face of a rotor cavity of the compressor housing. As a rotor of the compressor system rotates, the rotor may intermittently restrict the free-flowing scavenge flow returning from a lubricant separation tank. The rotor may be a male rotor having a plurality of male lobes. As the discharge end clearance between the rotor and the discharge end face is tightly controlled and monitored, a better control of the scavenge flow returning to the rotor cavity is achieved.

A scroll compressor including an orbiting scroll that performs an orbiting motion; a fixed scroll coupled to the orbiting scroll so as to form a compression chamber; and a main frame that rotatably supports the orbiting scroll at an opposite side of the fixed scroll with the orbiting scroll interposed therebetween, and supportably connected to the fixed scroll. The fixed scroll is provided with a back pressure hole formed between a first back pressure chamber in which gas discharged from the compression chamber is received, and the compression chamber. The back pressure hole may communicate with the first back pressure chamber and the compression chamber on the basis of a predetermined pressure ratio of the compression chamber.

A fluid compressor system has a scavenge loss limiter that increases the efficiency of the fluid compressor system by reducing the compressed working fluid recirculated into the airend through a scavenge flow. The scavenge loss limiter includes a scavenge hole positioned at a discharge end face of a rotor cavity of the compressor housing. As a rotor of the compressor system rotates, the rotor may intermittently restrict the free-flowing scavenge flow returning from a lubricant separation tank. The rotor may be a male rotor having a plurality of male lobes. As the discharge end clearance between the rotor and the discharge end face is tightly controlled and monitored, a better control of the scavenge flow returning to the rotor cavity is achieved.