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 compressor includes a shell, a compression mechanism and a fitting. The shell includes an opening and defines a chamber. The compression mechanism is disposed within the chamber of the shell. The fitting is attached to the shell at the opening. Working fluid flowing through the fitting flows to the compression mechanism. The opening is partially defined by a first edge and a second edge. The first edge includes a first planar surface and the second edge includes a second planar surface that faces the first planar surface. A first portion of the fitting extends at least partially into the opening and a second portion of the fitting abuts against the first and second edges.

Provided is a fluid machine configured such that liquid supplied to a working chamber from the outside of the fluid machine is dispersed extensively in the working chamber. This fluid machine is constituted of a screw rotor and a casing for accommodating the screw rotor and is provided with a liquid supply section for supplying liquid into a working chamber from the outside. The liquid supply section is configured so that liquid is dispersed in the longitudinal direction of the tooth groove of the screw rotor rather than in the width direction thereof.

A positive displacement device that converts energy, namely positive displacement compressors that rotate in a single rotational direction to displace working fluid contained in operating chambers. The device described herein is particularity advantageous for the ability to achieve high compression ratios in combination with high discharge pressure and high volumetric throughput in a single stage.

An oil-injected multistage compressor device that comprises at least one low-pressure stage compressor element (2) with an inlet (4a) and an outlet (5a) and a high-pressure stage compressor element (3) with an inlet (4b) and an outlet (5b), whereby the outlet (5a) of the low-pressure stage compressor element (2) is connected to the inlet (4b) of the high-pressure stage compressor element (3) via a conduit (6), characterized in that an intercooler (9) is provided between the low-pressure stage compressor element (2) and the high-pressure stage compressor element (3) in the aforementioned conduit (6) and that the compressor device (1) is also equipped with a restriction (10) for limiting the amount of oil injected in the low-pressure stage compressor element (2).

A pump cooling system may include a cooling body configured to be fitted to a pump housing to receive heat from the pump housing via a heat conducting path between the cooling body and pump housing. The cooling body may have a passage through which, in use, a cooling fluid is passed to conduct heat away from the cooling body. The pump cooling system includes a cooling control mechanism configured to provide a gap in the heat conducting path at pump operating temperatures below a predefined temperature so heat conduction from the pump housing to the cooling body is interrupted.

The present invention effectively cools air in a compression process at a high stage when an oil is supplied at the same pressure at a low stage and the high stage. Provided is a liquid-cooled type compressor including: a liquid-cooled type compressor body; at least one first nozzle; and at least one second nozzle, the at least one first nozzle and the at least one second nozzle each having a plurality of injection ports per nozzle and supplying a refrigerant through the injection ports into an inside of the compressor body, the second nozzle having the injection ports each having a diameter larger than a diameter of each of the injection ports of the first nozzle.

The present invention provides an oil feed type air compressor that can reduce a power consumption of a compressor body during an unload operation. The oil feed type air compressor includes: a compressor body (1) compressing air while feeding an oil into a compression chamber; a separator (4) disposed on a discharge side of the compressor body; a compressed air-feeding system (5) feeding the compressed air separated by the separator to a use destination of the compressed air; an oil-feeding system (6) feeding the oil separated by the separator to the compression chamber of the compressor body; an oil cooler (11) and a temperature sensor (12) disposed in the oil-feeding system; and a controller enabling execution of a temperature control. The temperature control by the controller is performed by variably controlling a rotation speed of a cooling fan (13) such that, during the load operation, a temperature detected by the temperature sensor is a target value T1, and during the unload operation, the temperature detected by the temperature sensor is a target value T2 (with the proviso of T1>T2).

A valve assembly forms a check valve for a scroll compressor including a fixed scroll having a pair of injection ports fluidly coupled to a compression mechanism. The valve assembly includes a valve body having a pair of flow paths with each of the flow paths fluidly coupled to a corresponding one of the injection ports. An injection plate has a pair of injection holes. A reed structure is disposed between the injection plate and the valve body with the reed structure including a pair of reeds. Each of the reeds is configured to selectively provide fluid communication between a corresponding one of the injection holes and a corresponding one of the injection ports. A valve gasket is disposed between the reed structure and the valve body and includes a pair of flaps with each of the flaps configured to selectively contact a corresponding one of the reeds.

Screw compressor with a compression chamber that is formed by a compression housing, in which a pair of meshed helical compressor rotors in the form of a screw are rotatably mounted and with a drive motor that is provided with a motor chamber formed by a motor housing, in which a motor shaft is rotatably mounted. The motor shaft drives at least one of the aforementioned two compressor rotors, where the compression housing and the motor housing are connected directly together to form a compressor housing, where the rotor shafts of the compressor rotors, as well as the motor shaft, extend along axial directions that are oblique or transverse to the horizontal plane. The motor chamber and the compression chamber have the same or similar pressure.