Abstract: Vacuum pump having a housing which defines a pump chamber and a drive chamber. A rotor is arranged in the housing, wherein the rotor has at least one rotor element arranged in the pump chamber for conveying a gaseous medium from an inlet to an outlet. Therein, the rotor extends from the pump chamber through a shaft feedthrough into the drive chamber. The shaft feedthrough has a connection, wherein the connection is connected to an underpressure, so that a barrier gas flows from the drive chamber at least partially through the shaft feedthrough to the connection.

Abstract: A screw vacuum pump comprises a housing forming a pumping chamber, wherein the housing is made of aluminum or an aluminum alloy. Further provided are two screw rotors arranged in the pumping chamber, each screw rotor comprising at least one displacer element having a helical recess for forming a plurality of windings, wherein the at least one displacer element is made of aluminum or an aluminum alloy. Between the region in which prevail 5% to 30% of the outlet pressure and a pressure-side end of the rotor (pump outlet), at least six, particularly at least eight, and with particular preference at least ten windings are provided.

Abstract: A vacuum pump screw rotor, comprising at least two helical displacer elements on a rotor shaft. The at least two displacer elements have different pitches, but the pitches of each displacer element are constant. Furthermore, the displacer elements each have a helical recess, each having a contour that remains the same over its entire length. Hereby, a suction-side displacer element has a recess having an asymmetric contour, and a pressure-side displacer element has a recess having a symmetrical contour.

Abstract: Dual- or multi-shaft vacuum pump comprising an engine, a first shaft and at least one second shaft, wherein the first shaft and the second shaft are synchronously driven by the motor via a common drive belt. The first shaft has a pumping element and the second shaft likewise has a pumping element which cooperates with the pumping element of the first shaft in order to convey a gaseous medium from an inlet to an outlet. The first shaft has a first emergency running gear and the second shaft likewise has a second emergency running gear which meshes with the first emergency running gear.

Abstract: A multi-stage rotary piston pump comprising two shafts in a housing, which support multiple rotary pistons. Corresponding rotary pistons form a respective rotary piston pair, wherein multiple rotary piston pairs are provided which form a respective pump stage. Neighboring pump stages are each connected to one another via connection channels. The multi-stage rotary piston pump also comprises a pump inlet that is connected to the first pump stage, as well as a pump outlet that is connected to the last pump stage. The built-in volume ratio is at least 15, so that high pumping capacities of at least 1500 m3/h can be achieved.

Abstract: 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.

Abstract: A screw rotor for screw vacuum pumps, comprising a rotor shaft which bears at least two displacement elements. The displacement element is conical in the conveying direction and the adjoining conveying element has a cylindrical design.

Abstract: A vacuum pump system for evacuating a chamber, in particular a lock or a process chamber, is provided that includes a main vacuum pump preferably configured as a screw pump. An inlet of the main vacuum pump is connected with the chamber to be evacuated. As seen in the feeding direction of the main vacuum pump an auxiliary vacuum pump is arranged which is in particular a Roots pump. An outlet area of the main vacuum pump is connected with a main outlet on the one hand and an inlet of the auxiliary vacuum pump on the other hand. Further, an outlet of the auxiliary vacuum pump is connected with the main outlet.

Abstract: A vacuum pump rotor comprises at least one displacement element arranged on a rotor shaft. The rotor shaft comprises at least one shaft end for a bearing element to be arranged thereon. The rotor element, the at least one displacement element and the at least one shaft end are made from aluminum or an aluminum alloy.

Abstract: A vacuum pump screw rotor, comprising at least two helical displacer elements on a rotor shaft. The at least two displacer elements have different pitches, but the pitches of each displacer element are constant. Furthermore, the displacer elements each have a helical recess, each having a contour that remains the same over its entire length. Hereby, a suction-side displacer element has a recess having an asymmetric contour, and a pressure-side displacer element has a recess having a symmetrical contour.

Abstract: A screw vacuum pump comprises a housing forming a pumping chamber, wherein the housing is made of aluminum or an aluminum alloy. Further provided are two screw rotors arranged in the pumping chamber, each screw rotor comprising at least one displacer element having a helical recess for forming a plurality of windings, wherein the at least one displacer element is made of aluminum or an aluminum alloy. Between the region in which prevail 5% to 30% of the outlet pressure and a pressure-side end of the rotor (pump outlet), at least six, particularly at least eight, and with particular preference at least ten windings are provided.

Abstract: A dry-compressing vacuum pump, in particular a screw pump, has two rotor elements (14) which are arranged in a pump chamber (12) and which are each carried by a rotor shaft (22). Two shaft ends of the rotor shafts (22) project through a side wall (28) of the pump housing (10). On the two shaft ends (28) there is arranged in each case one toothed belt pulley (38). Furthermore, a drive device and an electric motor for driving the rotor shaft (22) are provided. According to the invention, the rotor shafts (22) are driven by means of a toothed belt (40). To be able to use a toothed belt for drive purposes, a rotational flank clearance between the two rotor elements (14) of greater than ±0.75°, in particular greater than ±1°, is provided.

Abstract: A pump system comprising a vacuum pump and a cooling element connected to said vacuum pump. A coolant feed and a coolant discharge are connected to the cooling element for the purpose of cooling said vacuum pump by virtue of receiving and discharging heat using a coolant. The coolant feed and coolant discharge are connected to a heat exchanger such that heat is transferred from the coolant discharge to said coolant feed.

Abstract: A vacuum pump system comprising a plurality of vacuum pumps which are connected to one another in parallel and are each connected on an inlet side to a chamber, having an outlet line which is connected on the outlet side of the vacuum pumps, and an intermediate line which connects the inlet side of at least one vacuum pump to the outlet line, wherein all the vacuum pumps are connected in parallel during a pumping-out period and at least one of the vacuum pumps is connected in parallel with the other vacuum pumps as a backing pump during an idle period.

Abstract: A vacuum pump system for evacuating a chamber, in particular a lock or a process chamber, comprises a main vacuum pump preferably configured as a screw pump. An inlet of the main vacuum pump is connected with the chamber to be evacuated. As seen in the feeding direction of the main vacuum pump an auxiliary vacuum pump is arranged which is in particular a Roots pump. An outlet area of the main vacuum pump is connected with a main outlet on the one hand and an inlet of the auxiliary vacuum pump on the other hand. Further, an outlet of the auxiliary vacuum pump is connected with the main outlet.

Abstract: A Roots pump comprises a plurality of multi-toothed rotary pumps, each forming a pump stage, and connection channels connecting respective adjacent pump stages. The invention provides that the connection channels are arranged in partitioning walls separating the adjacent pump stages.

Abstract: A vacuum pump comprises pumping elements arranged in a pumping chamber. An electric motor drives the pumping element. A frequency inverter is provided for changing the rotational speed of the electric motor. The frequency inverter is arranged in a frequency inverter housing immediately connected to the pump housing. An air cooler and a liquid cooler are arranged in the frequency inverter housing to cool the frequency inverter.

Abstract: A Roots pump comprises a plurality of multi-toothed rotary pumps, each forming a pump stage, and connection channels connecting respective adjacent pump stages. The invention provides that the connection channels are arranged in partitioning walls separating the adjacent pump stages.

Abstract: A vacuum pump comprises pumping elements arranged in a pumping chamber. An electric motor drives the pumping element. A frequency inverter is provided for changing the rotational speed of the electric motor. The frequency inverter is arranged in a frequency inverter housing immediately connected to the pump housing. An air cooler and a liquid cooler are arranged in the frequency inverter housing to cool the frequency inverter.

Abstract: A vacuum pump system comprises two vacuum pumps which are connected to each other. In order to create vacuum pump system of a more compact size, the connection between the two vacuum pumps is performed via connection elements directly attached to the pump housing and forming connection sites, and the outlet flange of the upper pump is placed directly on the inlet flange of the lower pump without thereby causing a transmission of larger forces or moments.