A rotary compressor includes a drive mechanism, a compression mechanism, an introduction path to introduce a fluid into a compression chamber of the compression mechanism, and a backflow suppression mechanism. At least one of a first surface and a second surface of a valve body includes an annular first non-contact region that is formed in a predetermined range extending radially inward from an outer edge of the valve body and that does not come into contact with a corresponding valve seat, an annular second non-contact region that is formed in a predetermined range extending radially outward from the hole of the valve body and that does not come into contact with a corresponding valve seat, and a contact region that is formed between the first non-contact region and the second non-contact region and that comes into contact with a corresponding valve seat.

A moving part of a compressor, a compressor including the moving part, and a method of manufacturing the moving part, the moving part including a base material having a polished surface and including a steel material; an adhesive layer arranged on the polished surface; and a coating layer including diamond-like carbon. The adhesive layer may be arranged between the base material and the coating layer and bond the coating layer to the base material, and the base material may include an etching-processed area having a plurality of microgrooves (MG) extending in a downward direction into the base material from the polished surface.

A pump body assembly, a compressor and an air conditioner are provided. The pump body assembly has a crankshaft, a main bearing, and a cylinder body. The crankshaft has a main shaft part and an eccentric part connected with the main shaft part. The main bearing has a hub part. The main shaft part extends through a through hole in the hub part. A first oil guide groove is formed in the hole wall of the through hole. A sliding vane slot and a center hole are formed in the cylinder body. The crankshaft extends through the center hole. The main bearing is located at the one side of the cylinder body. The crankshaft and the main bearing are in uniform contact with oil films at all positions. The abnormal wear of the main shaft part of the crankshaft can be reduced, and the service life of the compressor can be prolonged.

A multistage compression system uses refrigerant and oil. The multistage compression system includes a low-stage compressor that compresses the refrigerant, a high-stage compressor that further compresses the refrigerant compressed by the low-stage compressor, refrigerant pipes that introduce the refrigerant compressed and discharged by the low-stage compressor into a suction part of the high-stage compressor, an intercooler, and an oil discharge pipe. The intercooler cools the refrigerant discharged by the low-stage compressor before the refrigerant is sucked into the high-stage compressor. The intercooler is disposed between the refrigerant pipes. The oil discharge pipe discharges the oil in the low-stage compressor. The oil discharge pipe connects the low-stage compressor and a portion of the refrigerant pipes. The portion of the refrigerant pipes is on an upstream side of the intercooler.

A pump body assembly, a compressor and an air conditioner are provided. The pump body assembly has a crankshaft, a main bearing, and a cylinder body. The crankshaft has a main shaft part and an eccentric part connected with the main shaft part. The main bearing has a hub part. The main shaft part extends through a through hole in the hub part. A first oil guide groove is formed in the hole wall of the through hole. A sliding vane slot and a center hole are formed in the cylinder body. The crankshaft extends through the center hole. The main bearing is located at the one side of the cylinder body. The crankshaft and the main bearing are in uniform contact with oil films at all positions. The abnormal wear of the main shaft part of the crankshaft can be reduced, and the service life of the compressor can be prolonged.

A compressor includes a casing having a cylindrical portion, a compression mechanism fixed to an inner peripheral surface of the cylindrical portion, an external portion, a welding nut, and a bolt. The external portion includes a temperature reaction portion that reacts to a temperature change of the cylindrical portion. The external portion is mounted on an outer peripheral surface of the cylindrical portion. The welding nut is welded to the outer peripheral surface of the cylindrical portion to mount the external portion on the outer peripheral surface of the cylindrical portion. The bolt fixes the external portion to the welding nut.

A multistage compression system uses refrigerant and oil. The multistage compression system includes a low-stage compressor that compresses the refrigerant, a high-stage compressor that further compresses the refrigerant compressed by the low-stage compressor, refrigerant pipes that introduce the refrigerant compressed and discharged by the low-stage compressor into a suction part of the high-stage compressor, an intercooler, and an oil discharge pipe. The intercooler cools the refrigerant discharged by the low-stage compressor before the refrigerant is sucked into the high-stage compressor. The intercooler is disposed between the refrigerant pipes. The oil discharge pipe discharges the oil in the low-stage compressor. The oil discharge pipe connects the low-stage compressor and a portion of the refrigerant pipes. The portion of the refrigerant pipes is on an upstream side of the intercooler.

A multistage compression system uses refrigerant and oil. The multistage compression system includes a low-stage compressor that compresses the refrigerant, a high-stage compressor that further compresses the refrigerant compressed by the low-stage compressor, an oil return pipe that returns the oil discharged by the high-stage compressor to the low-stage compressor, and an oil discharge pipe that discharges the oil in the low-stage compressor. The low-stage compressor includes a compression part that compresses the refrigerant, a motor that drives the compression part, and a container that houses the compression part and the motor. The container forms a high-pressure space storing compressed refrigerant. Inside of the oil return pipe and inside of the oil discharge pipe are connected to the high-pressure space.

A rotary compressor includes a compression mechanism having a cylinder, a piston, and a Helmholtz muffler. The Helmholtz muffler has a resonance chamber in the compression mechanism and a communication groove formed on an end face of the cylinder to connect the cylinder and resonance chambers. The communication groove is open at the end face of the cylinder and has a pair of side wall portions and a bottom wall portion between the side wall portions. Each side wall portion has a first portion adjacent an open end of the communication groove and a second portion adjacent the bottom wall portion. A surface of the first portion is a flat or bowed surface. A surface of the second portion is a bowed surface having a predetermined curvature so as to be connected to the surface of the first portion and a surface of the bottom wall portion.

The A compressor includes: a first cylinder, the first cylinder being provided with a first gas intake and a first gas outlet, the first air outlet being connected to a predetermined heat exchanger; a second cylinder, the second cylinder being provided with a second gas intake and a second gas outlet, and the second gas outlet being connected to the predetermined heat exchanger; and a gas pre-exhausting device. The gas pre-exhausting device is provided on a cylinder block of the first cylinder or on an upper end surface of the first cylinder or a lower end surface of the first cylinder; the gas pre-exhausting device) includes a gas pre-exhausting port and a first control valve controlling the gas pre-exhausting port to be open or closed; and the gas pre-exhausting port is connected to the second gas intake. Further disclosed is an air conditioner system including the compressor.