Abstract: A vacuum pump (1) comprising a pump chamber casing (5) accommodating two co-operating rotors (2, 3) which are respectively arranged on a shaft (8, 9). A bearing/gear chamber (6) is disposed adjacent to the pump chamber casing (5) in which the rotor shafts (8, 9) are cantilevered and provided with a synchronisation gear (17). A drive motor (25) whose drive shaft (28) extending parallel to the rotor shafts (8, 9) and is provided with a drive gear (35). A gear stage (37) is disposed between the drive shaft (28) and one of the rotor shafts (8, 9). In order to provide a machine of this type which can be embodied in a compact form, the drive gear (35) of the drive shaft (28) engages directly with a driven gear (36) on one of the rotor shafts (8, 9), forming the gear stage (37).

Abstract: A vacuum pump has two shafts (3, 4) and two rotors (1, 2) which co-operate with each other and which are fixed to the shafts. The rotors are cantilevered on the shafts. The rotors are fixed to the shafts in a manner which is devoid of backlash, even during temperature changes. In order to achieve this, the shafts (3, 4) are made of a material having a modulus of elasticity which is as high as possible, e.g., steel. The rotors (1, 2) are made of a material having a density which is as low as possible, e.g., aluminum or a titanium alloy. Structures (8; 11, 12, 13; 14, 15; 25, 27; 38, 41; 43, 44, 45; etc.) are provided to ensure that the rotors (1, 2) are fixed to the shafts (3, 4) in a manner which is devoid of backlash at all operating temperatures.

Abstract: A screw vacuum pump (1) has shafts (7, 8) and rotors (3, 4) secured to the shafts. Each rotor has a central hollow chamber (31) which receives the shaft or contains in built-in components rotating along with the rotor to define a relatively thin annular slot segment (32) for cross-flow circulation of coolant. The annular slot segment is disposed between the built-in components and an inner wall of the rotor's hollow chamber and between a suction side and a delivery side of the rotor. Separate feed and discharge lines (41, 55, 63, 77, 78, 81, 89, 99, 101, 103) circulate the coolant through the annular slot segment in such a way that the coolant remains cavitation-free and bubble-free.

Abstract: A vacuum pump has two shafts (3, 4) and two rotors (1, 2) which co-operate with each other and which are fixed to the shafts. The rotors are cantilevered on the shafts. The rotors are fixed to the shafts in a manner which is devoid of backlash, even during temperature changes. In order to achieve this, the shafts (3, 4) are made of a material having a modulus of elasticity which is as high as possible, e.g., steel. The rotors (1, 2) are made of a material having a density which is as low as possible, e.g., aluminum or a titanium alloy. Structures (8; 11, 12, 13; 14, 15; 25, 27; 38, 41; 43, 44, 45; etc.) are provided to ensure that the rotors (1, 2) are fixed to the shafts (3, 4) in a manner which is devoid of backlash at all operating temperatures.

Abstract: The invention relates to a vacuum pump (1) comprising a pump chamber casing (5) accommodating two co-operating rotors (2, 3) which are respectively arranged on a shaft (8, 9); a bearing/gear chamber (6) adjacent to the pump chamber casing (5) in which the rotor shafts (8, 9) are cantilevered and provided with a synchronisation gear (17); a drive motor (25) whose drive shaft (28) extends parallel to the rotor shafts (8, 9) and is provided with a drive gear (35); also comprising a gear stage (37) between the drive shaft (28) and one of the rotor shafts (8, 9). In order to provide a machine of this type which can be embodied in a compact form, the drive gear (35) of the drive shaft (28) engages directly with a driven gear (36) on one of the rotor shafts (8, 9), forming the gear stage (37).

Abstract: The invention9) relates to a screw vacuum pump (1) comprising shafts (7,8) and two rotors (3, 4)10) secured to the shafts, whereby each rotor has a central hollow chamber (31) provided with devices for circulating a coolant. In order to effectively cool the rotors (3, 4), built-in components rotating along with the rotor arc located in the chamber (31) of the rotors (3,4), said components forming a relatively narrow, annular slot segment (32) that is cross-flown by the coolant. The corresponding annular slot segment (32) extends between the built-in components and the corresponding inner wall of the rotor's hollow chamber (31) and between the suction side and the delivery side of the rotor (3,4). Supply of the annular slot segment (32) with coolant is carried out via separate feed lines and discharge lines traversing the shaft. Means are provided to ensure cavitation-free and bubble-free flow through the annular slot segment.

Abstract: A method of operating a claw-type vacuum pump with two or more stages, each of which has a suction chamber with a pair of claw rotors and end-located suction and discharge ports. To avoid the possibility of liquids affecting operation of the pump, the invention proposes that the pump is operated without internal compression and that the gases emerging from at least one stage are cooled.

Abstract: A muffler arrangement includes a muffler with an essentially cylindrical housing having a face end with a central entrance opening and at least one exit opening arranged other than centrally on the face end. Baffles are disposed within the housing, the baffles being concentrically arranged pipe cylinders which extend alternatingly into one another and are closed at one end, for effecting a multiple deflection of gases traveling from the central entrance opening to the at least one exit opening. A coupling structure is secured to the muffler housing, for carrying the muffler in an operating position. The coupling structure has a central passage for connecting the muffler to an exhaust outlet of a machine, and has an other than central channel, surrounding the central passage, for connection to an exhaust gas output conduit for outputting exhaust gases from the muffler arrangement.

Abstract: Dry-running twin-shaft vacuum pump (1) with at least one pumping chamber (11, 12, 13), with a rotor pair (4-5, 6-7, 8-9) situated in the pumping chamber and borne by the shafts, and with a drive housing (21); in the pumping of toxic media, to limit the contaminated areas to components that are easy to assemble it is proposed that between the drive housing (21) and the adjoining pumping chamber (13) an intermediate plate be provided, which is traversed by the shafts (2, 3), contains the laterally exiting exhaust duct (52), and is releasable from the wall (17) of the drive housing (21).

Abstract: The invention relates to a system for supplying inert gas to a multi-stage, dry-running vacuum pump (1) with systems for distributing the inert gas to the pump stages. To be able to monitor the flow of the inert gas and/or influence the rate of flow, a modularly constructed apparatus (36) with inert gas inlet, inert gas outlets and inert gas conduits is proposed, which is equipped with monitoring components.

Abstract: The invention relates to a method for the operation of a multi-stage, dry compression vacuum pump (1) with an inlet (7) and an outlet (9), in which the aspirated gases contain gaseous components which endanger the operation of the vacuum pump; in order to render the gas components harmless it is proposed that the gases aspirated from the vacuum chamber (8) and flowing through the vacuum pump be carried through a reaction chamber (14) in which the components endangering the vacuum pump are chemically or physically treated at a pressure between the aspiration pressure and the outlet pressure of the vacuum pump.