A dry-compressing compressor comprises two screw rotors in a housing defining a suction chamber. At a compressor inlet of the compressor preferably atmospheric pressure prevails and at a compressor outlet of the compressor preferably a pressure of more than 2 bars (absolute) prevails. For each screw rotor at least one displacement element including a helical recess defining a plurality of windings is provided. The at least one displacement element per screw rotor has a single-pass asymmetrical profile.

A dry-running vane gas pump includes a pump housing which forms a pump chamber, a pump rotor with at least one displaceable slide element which pump rotor is rotatably supported in the pump chamber, at least one fluid inlet opening associated with the pump chamber, a first fluid outlet opening associated with the pump chamber, a second fluid outlet opening associated with the pump chamber, and a non-return valve which closes the first fluid outlet opening. The second fluid outlet opening is permanently open. The first fluid outlet opening is arranged before the second fluid outlet opening in a direction of rotation of the pump rotor.

A vacuum system is disclosed. The vacuum system includes a first pump bay and a second pump bay enclosed by an enclosure. Each pump bay houses a motor and a vacuum pump driven by the motor. An inlet manifold and an exhaust manifold are in fluid communication with the first and second pump bays. The inlet manifold and the exhaust manifold are arranged to flow air through the pump bays to cool at least the vacuum pumps.

A screw compressor includes a first rotor and a second rotor, and each rotor is provided with a synchronisation gear. The screw compressor is further provided with an electric motor and one or two driving gears for driving the first rotor or second rotor. At least one of the synchronisation gears or driving gears is provided with spokes between a rim supporting a gear mesh and a corresponding gear hub.

The present invention relates to a technology of efficiently cooling a vacuum pump that produces a vacuum in a process chamber of a semiconductor manufacturing facility. The present invention provides a new type of vacuum pump cooling method that keeps the internal temperature of a vacuum pump at a predetermined level by circulating oil through rotors of the vacuum pump, such that it is possible to prevent a rapid increase in the temperature of the vacuum pump and smoothly lubricate bearings at the early stage of operation, whereby it is possible to ensure stability when performing processes and operating the pump and economically maintain the facility.

A pumping unit is provided, including a primary vacuum pump of a multistage dry type, including at least four pumping stages fitted in series; and a two-stage Roots vacuum pump, including a first pumping stage and a second pumping stage fitted in series, the second pumping stage being fitted in series with and upstream of a first pumping stage of the primary vacuum pump in a direction of flow of gases to be pumped, in which a ratio of a volume displacement of the first pumping stage of the two-stage Roots vacuum pump to a volume displacement of the second pumping stage of the two-stage Roots vacuum pump is less than six, and in which a ratio of a volume displacement of the second pumping stage of the two-stage Roots vacuum pump to a volume displacement of the first pumping stage of the primary vacuum pump is less than six.

A method is for surveillance of an operating state of a pumping device connected to a process chamber in order to determine a failing operating state of the pumping device. The pumping device includes at least one rough-vacuum pump including a motor for driving the rough-vacuum pump and a variable speed drive to control the rotation speed of the motor, to receive a first input parameter corresponding to a set point frequency and a second input parameter corresponding to a motor current, and to deliver to the motor an output parameter corresponding to a control frequency. A failing operating state is determined when in steady-state operation the difference between the first input parameter and the output parameter is equal to or exceeds 10% of the first input parameter for a predetermined time greater than 3 seconds. The method can be implemented in a pumping device and an installation.

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.

The invention relates to a rotary vane vacuum pump comprising a housing member whose inner wall defines at least one pumping space, and a rotor that is arranged for rotation in the pumping space and has a rotor member and at least one vane, wherein the vane projects radially beyond the rotor member and together with the inner wall of the housing body a pumping volume that can be pumped by rotation of the rotor from an inlet to an outlet of the rotary vane vacuum pump, wherein the vane, at least in a region cooperating with the inner wall, comprises a polytetrafluoroethylene material containing polyimide particles and manufactured by hot pressing and sintering, and wherein the inner wall has a slide layer at least in a region cooperating with the vane, said slide layer comprising an oxide layer formed by anodic oxidation in an electrolyte including oxalic acid.

The present invention provides a method of ceasing rotation of a rotor of a vacuum pump. The method comprises the steps of rotating the rotor at an intermediate RPM, at which there is substantially no probability of the rotor clashing with the stator, for a dwell time sufficient for the vacuum pump to be at or below a threshold temperature, and subsequently coasting down the rotation of the rotor until cessation of rotation.