A screw compressor includes plural screw rotors, plural suction-side bearings that each rotatably support the suction side of the plural screw rotors and plural discharge-side bearings that each rotatably support the discharge side of the plural screw rotors, and a casing that houses the plural screw rotors, the plural suction-side bearings, and the plural discharge-side bearings. Each screw rotor includes a lobe section with plural lobes and a suction-side shaft section and a discharge-side shaft section each disposed at both ends of the lobe section. The casing has a housing chamber that houses the lobe sections of the plural screw rotors and a lubrication path in which liquid that lubricates the plural suction-side bearings circulates. In the lubrication path, respective passages to lubricate each of the plural suction-side bearings are connected in series and a most downstream part is connected to the housing chamber.

A compressor includes a container provided with an oil reservoir which is provided at a bottom portion of the container to allow oil to be collected in the oil reservoir. In the container, an electric motor mechanism, a rotary shaft, a compression mechanism, and a frame which fixes the compression mechanism to the container are provided. In the frame, a suction port is formed to cause refrigerant having flowed into the space to flow into the compression mechanism, and each of a suction portion and a connection port of the suction pipe, is located at a position which is higher than or the same as the level of the rotary shaft as seen in a rotation axial direction A rib in a first flow passage extends downwards in the direction of gravity from the connection port, extends through an area located above the oil reservoir, and reaches the suction port.

An oil-lubricated rotary vane vacuum pump includes a rotary vane unit, having a rotary vane chamber and a rotary vane rotor, and an oil separator device having an air/oil separating unit that has a filter element with a plug-in ring that can be plug-connected on a housing side. The plug-in ring is designed for radial sealing and axial displaceability in a housing receptacle. The filter element has a moulding for bayonet mounting, which faces the end associated with the outer wall. A mounting wall of the housing, extending at a distance from the outer wall of the housing, is designed to interact with the moulding of the filter element and to form the bayonet mounting. A separate cover closes a mounting opening associated with the filter element in the outer wall of the housing. The cover form-fittingly interacts with the filter element to secure the filter element against rotation.

A liquid-injected compressor or vacuum pump device with a liquid-injected compressor or vacuum pump element (2), which includes a liquid return system (7), a motor (4) to drive the compressor or vacuum pumping element (2), a gearbox (3) provided between the motor (4) and the liquid-injected compressor or vacuum pump element (2), and a liquid separator vessel (5) in fluid connection with an outlet (6) of the compressor or vacuum pump element (2). The liquid return system (7) includes a main body (8) with a chamber in which a first compressed gas flow (11) from the liquid separator vessel (5) and a second fluid flow (15) from the gearbox (3) are mixed together to form a third fluid flow (20). The third fluid flow (20) leaves the chamber via an outlet (16) and is directed into the liquid-injected compressor or vacuum pump element (2) via the injection point (17).

A scroll compressor having a casing, a drive motor which is held in place within the casing and has an internal flow passage and an external flow passage to pass through, a rotation shaft which is combined with the drive motor for rotation, a frame that is provided under the drive motor and through which the rotation shaft passes for support, a first scroll which is provided under the frame and on whose one flank surface a first wrap is formed, a second scroll which is provided between the frame and the first scroll, on which a second wrap that is engaged with the first wrap is formed, with which the rotation shaft is eccentrically combined and which forms a compression chamber, and a flow passage separation unit which separates a space between the drive motor and the frame into an internal space and an external space is provided.

The compressor includes a rotor that applies rotational power to a compressor unit, wherein the rotor includes a rotor core and an upper rotor-end plate, the rotor core has a plurality of through-holes through which a refrigerant passes, the upper rotor-end plate covers the upper rotor-end face of the rotor core, where one end of each of the plurality of through-holes is formed, the upper rotor-end plate has a plurality of upper openings that allow communication of the plurality of through-holes with an internal space in a compressor container, the plurality of upper openings are adjacent to the plurality of through-holes in the upper rotor-end face, and a plurality of upper inner peripheral-side adjacent areas, which are on the inner peripheral-side closer to a rotation axis than the plurality of through-holes, are exposed to the internal space.

A compressor is provided that may include a passage separator provided between an electric motor drive and a compression device to separate a refrigerant passage from an oil passage. The passage separator may include a first partition wall and a second partition wall. The first partition wall may be disposed between an inner circumferential surface of a casing and a discharge hole of the compression device, and the second partition wall may be disposed between the discharge hole and a balance weight. Accordingly, the refrigerant passage may be separated from the oil passage between the compression device and electric motor drive, thereby efficiently recovering oil to an oil storage space.

A scroll compressor includes a refrigerant discharge flow passage and an oil recovery flow passage that are separated from each other. The scroll compressor further includes a flow passage separation unit configured to separate an intermediate space between a drive portion and a compression portion into an inner space communicating with the refrigerant flow passage and an outer space communicating with the oil flow passage to separate the refrigerant discharge path from the oil recovery path.

The liquid level of a liquid supply type compressor including a gas-liquid separator is dynamically monitored. A liquid supply type gas compressor includes a compressor body of a liquid supply type; a gas-liquid separator that separates a liquid from a compressed gas, which is discharged, to store the liquid; a liquid piping system that supplies the liquid stored to the compressor body; an internal pipe that extends in an internal space of the gas-liquid separator, and includes at least two hole portions, of which disposition positions are different from each other in a height direction, on an internal space side to communicate with the liquid piping system; and a detector that detects a pressure or a temperature of a fluid flowing through the liquid piping system. At least one of a determination as to whether or not the pressure or the temperature detected by the detector is more than a first set value set in advance and a determination as to whether or not the pressure or the temperature detected by the detector is less than a second set value which is set in advance to be less than the first set value is performed to determine which one of the gas and the liquid is the fluid flowing through the liquid piping system.

Oleophobic and/or philic surface(s) are utilized for oil separation, direction, and/or collection in a refrigeration system. Surfaces of component(s) of a refrigeration system (compressor, oil separator, evaporator, etc.) are produced to be oleophobic or philic. The oleophobic and/or philic surfaces are utilized to direct a flow path of oil within the refrigeration system or to prevent oil connection in an area. Refrigerant phobic and/or lubricant phobic material(s) also may be utilized to help promote separation of refrigerant vapor from refrigerant liquid and/or from oil in refrigeration systems.