A multi-stage rotary vane pump comprising at least two rotor elements. The rotor elements are supported by a rotor shaft. The rotor elements and the rotor shaft are in the form of a single piece.

A vacuum exhaust system which exhausts gas from chambers and which comprises a plurality of branch channels for the exhaustion of the gas from the chambers, a main pipeline in the form of a confluence of the plurality of branch channels, channel open-close valves fitted to correspond with each of the said plurality of branch channels, a channel-switching valve connecting the main channel and a plurality of selection channels and allowing flow between the main channel and any one of the plurality of selection channels, a first pump which functions as a gas exhaust means in the molecular flow region of the gas and is fitted to one of the plurality of branch channels, and second pumps which function as gas exhaust means in the viscous flow region of the gas and are fitted to the plurality of selection channels.

The present disclosure provides a multi-stage compressor and an air conditioner having the same. The multi-stage compressor includes: a first-stage cylinder including a first-stage compression cavity and a first vane disposed in the first-stage compression cavity; a second-stage cylinder including a second-stage compression cavity and a second vane disposed in the second-stage compression cavity, wherein a refrigerant flowing out from the first-stage compression cavity enters the second-stage compression cavity; a linkage structure disposed between the first vane and the second vane, so that the second vane is capable of moving with a movement of the first vane and maintain contact with a roller in the second-stage compression cavity.

A pumping system is provided, including a rough-vacuum pump; a Roots vacuum pump including a pumping stage having a stator inside which two Roots rotors are configured to rotate synchronously in opposite directions to drive a gas to be pumped between an inlet orifice and an outlet orifice; and a pipeline connecting the outlet orifice to an intake of the rough-vacuum pump, a shortest distance between an edge of the outlet orifice and each of the Roots rotors in the pumping stage being less than 3 cm, and the outlet orifice being situated at the end of an upstream tube of the pipeline that passes into the pumping stage.

A vacuum system having a condenser and a root vacuum pump set includes an independent inlet condenser set having an inlet end for receiving vapor inputted from an output of an air cooling power generator condenser of a generator; air in the vapor being condensed, and the surplus air is outputted; a root vacuum pump set including at least one root vacuum pump; the root vacuum pump set further including an input end and an output end; the input end being connected to the independent inlet condenser set; air outputted from the independent inlet condenser set being inputted to the at least one root vacuum pump for compression and then the compressed air being outputted from the output end; and a backing pump connected to the output end of the root vacuum pump set by using an output pipe; the backing pump serving to receive air outputted from the root vacuum pump set.

A system comprising an electric motor, a compressor configured to be driven by the electric motor, a plurality of valves in fluid communication with an output of the compressor, a rotor disposed adjacent the valves and configured to spin as the valves control fluid movement toward the rotor, and a magnet is coupled to the rotor and configured to spin within a stator, wherein the compressor causes fluid to move through the valves thereby causing the rotor to spin the magnet, which in turn generates an electrical current.

A fluid delivery device has a primary pump and a main pump fluidically connected to the primary pump. The primary pump can be driven by a primary pump input shaft, the main pump can be driven by a main pump input shaft, and the primary pump input shaft and the main pump input shaft are mechanically coupled to a common drive shaft of the fluid delivery device. The primary pump is in the form of a non-compensated gear pump or a centrifugal pump and the main pump is in the form of a compensated internal gear pump.

The invention relates to a method for controlling a rotary screw compressor, having at least a first and a second air-end, wherein both air-ends are driven separately from one another and speed controlled. According to the invention, the following steps are carried out: detection of a volume flow taken at the outlet of the second air-end; adjustment of the rotational speed of both air-ends, when the removed volume flow fluctuates in a range between a maximum value and a minimum value; opening of a pressure-relief valve, if the volume flow falls below the minimum value; and reduction of the rotational speed of at least the first air-end to a predetermined idling speed (V1.sub.L) to reduce the volumetric flow delivered by the first to the second air-end.

The invention relates to a screw pump having two screws, in which screw pump each screw has a first thread and a second thread. The threads extend in each case from a suction side to a delivery side. The threads are in engagement with one another, with the result that the threads are divided into a plurality of working chambers, the volume of which decreases from the suction side to the delivery side. According to the invention, the threads have two thread turns. Moreover, the invention relates to a screw for a pump of this type. On account of the uniform distribution of mass of the two-turn threads, the pump can be operated at a high rotational speed, with the result that the throughput of the pump is increased.

A dryer for a compressed gas provided with a vessel with a drying agent and a drying zone and a regeneration zone; at least one intermediate zone that, viewed in the direction of rotation of the drum, is situated between the regeneration zone and the drying zone and which is provided with a separate inlet and an outlet that is shared with or connected to the outlet of the regeneration zone; a tap-off pipe that branches off from the outlet of the drying zone and connects to the aforementioned separate inlet of the intermediate zone; means for effectuating an intermediate flow from the drying zone, whereby the dryer is configured such that the entire flow of gas to be dried supplied to the dryer is first guided through the regeneration zone, wherein the aforementioned means are only formed by one or more blowers in the aforementioned tap-off pipe.