A scroll compressor includes a casing, a low-pressure space and a compression mechanism. The compression mechanism includes fixed and movable scrolls, a fluid chamber including first and second compression chambers, and an adjustment mechanism. The fluid chamber has different discharge start points between the first and second compression chambers. An oil inflow groove is formed in one sliding surface, and an oil relief passage is formed in the other sliding surface. The oil relief passage includes a communication portion that communicates with the oil inflow groove in a predetermined angular range, lubricating oil flowing from the oil inflow groove into the low-pressure space through the communication portion. The predetermined angular range is from a position between a discharge start point of the first compression chamber and a discharge start point of the second compression chamber to a position after the discharge start of the second compression chamber.

A control system comprising: a suction line; an exhaust line; an operating liquid line; a liquid ring pump comprising a suction input coupled to the suction line, an exhaust output coupled to the exhaust line, and a liquid input coupled to the operating liquid line; a motor configured to drive the liquid ring pump; a first sensor configured to measure a first parameter of an exhaust fluid of the liquid ring pump; a second sensor configured to measure a second parameter of a gas being received by the liquid ring pump via the suction line; and a controller operatively coupled to the first sensor, the second sensor, and the motor, and configured to control the motor based on sensor measurements of the first sensor and the second sensor.

A scroll compressor includes a compression mechanism having fixed and movable scrolls forming a compression chamber, a motor to drive the movable scroll, a drive shaft, a casing, a housing accommodated inside the casing, and a floating member supported by the housing. The casing accommodates the compression mechanism, the motor, and the drive shaft. The floating member can be pushed toward the movable scroll by a pressure in a back pressure space formed between the floating member and the housing. The floating member may include a plurality of supported portions arranged circumferentially at three or more locations, and the housing may include a supporting portion supporting the supported portions. Alternatively, the floating member may include a body member and an outer peripheral member separate from the body member, the outer peripheral member mounted to an outer periphery of the body member, and the housing supports the outer peripheral member.

A compressor casing having an internal gas passage includes a first bearing housing arranged at a first end of the casing, a second bearing housing arranged at a second, opposite end of the casing, and a rotor case disposed between the first bearing housing and the second bearing housing. The rotor case includes an axially extending bore within which a plurality of rotors are receivable and a hollow internal cavity isolated from the bore. The internal cavity is fluidly coupled to the bore via at least one recess. At least one exit opening is formed in one of the first bearing housing and the second bearing housing. The at least one exit opening is operably coupled to the internal cavity of the rotor case.

A screw compressor of the present invention comprises: a housing having a compression chamber; male and female rotors provided in the compression chamber; a driving shaft for rotating the male and female rotors; and a seal cover across which the driving shaft is provided, and further includes: an oil chamber provided at the seal cover, and returning, to the compression chamber, oil having leaked into the driving shaft; and a breather for injecting external air into the oil chamber. Therefore, the breather is provided at the upper part of the oil chamber and an oil recovery line is provided at the lower part thereof so as to cause a pressure difference between the upper and lower parts of the oil chamber, such that the flow of the oil having leaked into the driving shaft is smoothly recovered in the oil recovery line.

A bearing oil feeding amount is appropriately controlled with respect to specifications of a discharge pressure (bearing load) and a rotation speed. A gas compressor has: a compressor main body that compresses gas and has a rotor; a bearing for supporting the rotor onto a compressor main body casing; an oil case that stores a lubricating oil to be supplied to the bearing; a lubricating oil pipe through which the lubricating oil is circulated from the oil case to the bearing; an oil pump that pumps the lubricating oil from the oil case to the bearing via the lubricating oil pipe; a flow amount control means for adjusting an amount of lubricating oil that circulates through the lubricating oil pipe; an electric motor that supplies power to the rotor; an inverter that outputs a rotation frequency of the electric motor; a pressure sensor that detects the discharge pressure of the compressor main body; and a control unit that determines a lubricating oil supply amount to the bearing on the basis of the load on the bearing corresponding to the pressure detected by the pressure sensor and the rotation speed of the rotor corresponding to the rotation frequency output by the inverter, and that controls the flow amount control means on the basis of the lubricating oil supply amount.

Disclosed is a multi-stage compressor, including a gas supplement structure, a low-pressure stage chamber and a high-pressure stage chamber. The gas supplement structure includes a gas supplement inlet and a perforated member, wherein the gas supplement inlet is arranged at an upstream location of an exhaust gas flow of the low-pressure stage chamber; the perforated member is arranged at a downstream location of the exhaust gas flow of the low-pressure stage chamber; a liquid refrigerant sprayed from the gas supplement inlet is mixed with exhaust gas of the low-pressure stage chamber to impact on the perforated member; the liquid refrigerant is dispersed, the dispersed liquid refrigerants are re-mixed with the exhaust gas of the low-pressure stage chamber and enter the high-pressure stage chamber.

An oil-flooded screw compressor system includes: a first lubricating oil supply system for supplying lubricating oil to screw parts; and a second lubricating oil supply system for supplying the lubricating oil to a bearing. The first lubricating oil supply system includes: a gas-liquid separator; a first supply flow passage; and a first supply path. The second lubricating oil supply system includes: a lubricating oil reservoir; a second supply flow passage; a second supply path; a first discharge flow passage; and a discharge path. It is possible to suppress dissolution of a gas to be compressed in lubricating oil and to suppress damage to a bearing due to deterioration of the performance of the lubricating oil, even in a case where the gas to be compressed is compatible with the lubricating oil.

A scroll compressor includes a pillar-shaped member that is inserted into a scroll-side engagement section formed on a stationary scroll. A lower end-face of an engagement section between the pillar-shaped member and the scroll-side engagement section is located above a lap end-face of a stationary spiral lap.

A scroll compressor is provided that may include a casing that contains oil in a lower space thereof; a drive motor provided at a position spaced from an upper end of the casing by a predetermined gap, such that an upper space is formed in the casing; a rotational shaft coupled to a rotor of the drive motor, and having an oil supply passage to guide the oil contained in the casing to an upper side of the drive motor; a frame provided below the drive motor; a fixed scroll provided below the frame, and having a fixed wrap; an orbiting scroll provided between the frame and the fixed scroll, having an orbiting wrap so as to form a compression chamber by being engaged with the fixed wrap, and a rotational shaft coupling portion to couple the rotational shaft to the orbiting scroll in a penetrating manner; and an oil collection unit including an oil separator provided at the upper space of the casing, and an oil guide having a first end that communicates with the oil separator and a second end that communicates with a lower space of the fixed scroll.