A technique is provided that can further reduce power at the time of “unload operation control” in a gas compressor that generates a compressed gas at a set pressure by constant-speed control. The gas compressor includes a compressor main unit, a drive source, an intake throttle valve, a gas release valve, rotation speed converting means, a pressure detecting device that detects a discharge pressure, and a controller that, the relationship between an upper-limit pressure H and a lower-limit pressure L being H>L, carries out opening the intake throttle valve and closing the gas release valve and operating the drive source at a full-load rotation speed until the discharge pressure reaches the upper-limit pressure H. The controller carries out at least one of closing the intake throttle valve and opening the gas release valve to reduce the discharge pressure to within a predetermined range when the discharge pressure reaches the upper-limit pressure H. The controller carries out switching to load operation when the discharge pressure drops to the lower-limit pressure L. In the gas compressor, the controller outputs a command of a lower rotation speed than the full-load rotation speed to the rotation speed converting means when the discharge pressure rises and reaches the upper-limit pressure H. The controller outputs a command of the full-load rotation speed to the rotation speed converting means when the discharge pressure drops and reaches the lower-limit pressure L.

A vacuum pump, vacuum pump arrangement and method are disclosed. The vacuum pump includes at least one rotor; and a stator, an inlet for receiving gas during operation; and an exhaust for exhausting the gas. The vacuum pump includes a shaft extending through a centre of said pump and comprising a plate mounted on an end of the shaft towards the inlet. The vacuum pump includes control circuitry configured to control an axial position of the plate, a change in axial position of the plate providing a change in inlet conductance of gas to the vacuum pump. The plate is mounted such that it extends beyond the inlet in at least some axial positions of the rotor such that the plate is not on the same side of the inlet as the stator.

A vacuum pump and vacuum assembly. The vacuum pump comprises: an inlet for receiving gas; and an exhaust for exhausting the gas; a hollow shaft defining an axial passage extending through the pump from an opening in a base of the pump to an opening axially beyond the pump inlet. The shaft comprises an end remote from the base of the pump, the end being configured to attach to a cathode plate within a vacuum chamber evacuated by the vacuum pump. The shaft is configured for axial movement of the end between at least one open position in which the end is remote from the inlet of the vacuum pump and a sealing position in which the end is closer to the inlet.

A system is provided and includes a compressor. The compressor further includes a diffuser frame, a gas or oil actuator and a drive system. The diffuser frame defines a first channel through which compressed fluids are flowable, a second channel intersecting the first channel and a third channel extending from the second channel. The gas or oil actuator includes a piston and a head integrally coupled to the piston. The head and the piston are disposable in the second and third channels, respectively. The piston is movable in forward or reverse directions through the third channel such that the head is movable through the second channel and into or out of the first channel, respectively. The drive system is at least partially disposable in the third channel and configured to drive forward and rearward movements of the piston.

A compressor for a supercharging device of an internal combustion engine and a supercharging device are described. The compressor has an iris diaphragm mechanism that has a special drive. The drive includes an adjusting ring as an integral constituent part of an actuator of the drive and is formed as a rotor, which surrounds an air supply channel, of an electric motor. This results in a significantly simplified structural form of the drive.

This invention relates to a compressor 100 for a supercharger 10. The compressor 100 comprises a compressor housing 110 with a compressor inlet 112 and a compressor outlet 114. The compressor 100 furthermore comprises an adjustment mechanism 200 and an actuator device 300. The adjustment mechanism 200 comprises an adjustment ring 210 and a plurality of shutter elements 220 for changing an inlet cross section 112a of the compressor inlet 112. The actuator device 300 comprises a drive unit 310 and a coupling unit 320. The actuator device 300 is thus coupled, via the coupling unit 320, to the adjustment mechanism 200 in order to move the adjustment mechanism 200 between a first position and a second position.

A turbocharger includes a compressor equipped with an inlet-adjustment mechanism disposed in the air inlet of the compressor, the inlet-adjustment mechanism including a plurality of arcuate blades distributed about a circumference of a circle and partially overlapping one another so as to form an uninterrupted 360-degree blade ring. Each blade is pivotable about a respective fixed pivot point such that the ring is adjustable between a maximum-open position and a minimum-open position, the ring being adjustable via simultaneous coordinated pivoting of the blades about the respective fixed pivot points. The blades are structured and arranged to form said uninterrupted 360-degree blade ring in the maximum-open position and the minimum-open position and any intermediate position therebetween.

A vacuum pump, vacuum pump arrangement and method are disclosed. The vacuum pump includes at least one rotor; and a stator, an inlet for receiving gas during operation; and an exhaust for exhausting the gas. The vacuum pump includes a shaft extending through a centre of said pump and comprising a plate mounted on an end of the shaft towards the inlet. The vacuum pump includes control circuitry configured to control an axial position of the plate, a change in axial position of the plate providing a change in inlet conductance of gas to the vacuum pump. The plate is mounted such that it extends beyond the inlet in at least some axial positions of the rotor such that the plate is not on the same side of the inlet as the stator.

A centrifugal compressor includes: a housing including an intake flow path; a compressor impeller disposed in the intake flow path; an accommodation chamber formed upstream of the compressor impeller in the housing; a movable member disposed in the accommodation chamber and configured to be movable between a retracted position where the movable member is retracted from the intake flow path and a protruding position where the movable member protrudes from the accommodation chamber into the intake flow path, the protruding position being located closer to the intake flow path with respect to the retracted position, and a contacting portion and a non-contacting portion provided on an accommodation chamber opposing surface of the accommodation chamber, the accommodation chamber opposing surface being positioned upstream of the movable member, the contacting portion being contactable with the movable member, the non-contacting portion being non-contactable with the movable member.

An HVAC system includes an unloading device, a centrifugal compressor, a gas foil bearing, a VFD and a controller. The controller is programmed to start the centrifugal compressor from a stopped condition by operating the unloading device to remove a load from the centrifugal compressor, accelerating the motor to a first speed above a liftoff speed of the gas foil bearing and below an operating speed of the centrifugal compressor, running the motor for a period of time, operating the unloading device to apply the load to the centrifugal compressor, and accelerating the motor to the operating speed.