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).

The present disclosure provides a compressor system operable for compressing a working fluid such as air. A conditioner is positioned upstream of the compressor to reduce the humidity and in some embodiments may control a temperature of the working fluid entering the compressor. A working fluid aftercooler and a lubricant cooler is positioned downstream of the compressor. A first heat exchange system directs water from a source through the conditioner and then to the aftercooler and oil cooler in parallel. A second heat exchange system directs oil from the compressor to the oil cooler and then to a regenerator prior to reentry into the compressor. A control system with one or more control valves is configured to provide oil to the compressor at a target temperature defined to ensure that the temperature of the discharged compressor is above a pressure dew point temperature.

Liquid injected screw compressor with an inlet valve and blow-off valve; a liquid circuit with injector; a controller for the transition from unloaded to loaded, whereby when unloaded the inlet valve is closed and the blow-off valve is open, and when loaded the inlet valve is open and the blow-off valve is closed, and whereby during an aforementioned transition, when the injection pressure is below a minimum threshold, the inlet valve remains closed and is opened with a certain delay and that there are means to gradually increase the injection during this delay and to open the inlet valve when the injection pressure has reached the minimum threshold.

A screw compressor, refrigerant circuit, lubrication method are disclosed. The screw compressor includes a suction inlet that receives a working fluid to be compressed. A compression mechanism is fluidly connected to the suction inlet. A discharge outlet is fluidly connected to the compression mechanism that outputs the working fluid following compression by the compression mechanism. The screw compressor includes a slide valve that is movable between a first position and a second position. The first position corresponds to a high volume ratio and the second position corresponds to a low volume ratio. The slide valve includes a plurality of lubricant passageways selectively connectable to a lubricant source. A first of the plurality of lubricant passageways is configured to be selected to provide lubricant at the high volume ratio, and a second of the plurality of lubricant passageways is configured to be selected to provide lubricant at the low volume ratio.

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 hand-held inflation device comprising: a first housing (10) in which a motor (11) is mounted; a second housing (20) in which a compression means (21) for generating compressed air is mounted; the second housing (20) is rotatably mounted to the first housing (10) such that the second housing (20) is foldable relative to the first housing (10) between a folded position and an extended position; coupling means (22) for coupling the motor (11) to the compression means (21) in at least one position between the folded position and the extended position, such that the motor (10) is capable of driving the compression means (21).

An oil-injected screw air compressor includes a first stage compression chamber, an air buffering chamber, a second stage compression chamber, an oil cooler, a plurality of sensors, and a controller. The air buffering chamber is coupled to the first stage compression chamber. The second stare compression chamber is coupled to the air buffering chamber. The oil cooler cools the lubricating oil for the first stage compression chamber, the air buffering chamber and the second stage compression chamber. The sensors are respectively located at outlets of the first stage compression chamber, the air buffering chamber and the second stage compression chamber. The controller respectively and dynamically controls flow rates of the lubricating oil entering into the first stare compression chamber, the air buffering chamber and the second stage compression chamber according to temperature and pressure data measured by the sensors.

A two-stage oil-injected screw air compressor includes an integrated compression casing, and the integrated compression casing further includes a first stage compression chamber, an intermediate cooling channel, and a second stage compression chamber parallel stacked in the integrated compression casing. A straightforward oil injector aims at the intermediate cooling channel to spray lubricating oil into the intermediate cooling channel.

A dry type primary vacuum pump is provided, including at least two pumping stages mounted in series between a suction and a discharge of the pump; two rotors extending in the pumping stages and being configured to rotate synchronously in a reverse direction to drive a gas to be pumped between the suction and the discharge; an injection device configured to distribute a purge gas in at least one pumping stage, the injection device including at least one injector and at least one injection valve with an on or off control configured to be interposed between a purge gas supply source and the injector; and a control device configured to control opening and closing of the injection valve to inject a purge gas by successive pulses into the at least one pumping stage. A method for controlling the injection of a purge gas the vacuum pump is also provided.

A compressor includes a housing, a partition, a first scroll, a second scroll, and a valve assembly disposed within the second scroll. The valve assembly includes a valve housing, a valve body, and a first biasing member configured to displace the valve body from a first position to a second position relative to the valve housing. When in the first position, the valve body inhibits fluid communication between a fluid source and one of a series of compression pockets formed by the first and second scroll. When in the second position, the valve body allows fluid communication between the conduit and one or more of the series of compression pockets. The valve body is displaceable between the first and second positions in response to a change in operating temperature of the compressor.