Abstract: The invention relates to an oscillating piston pump (1), in particular to an oscillating piston vacuum pump. The invention aims to create a range of pumps of this type comprising members which exhibit a different final pressure behaviour and/or a different pumping capacities. To achieve this, the range consists of several identically constructed modules (2) of an oscillating piston pump that are connected in parallel and/or in series, according to customer requirements and each module is equipped with an oscillating piston drive.

Abstract: The vacuum pump (10) comprises a stator (14) in which a rotor (12) with radial magnetic bearings (16,19) and with an axial magnetic bearing (40) is mounted in a contactless manner. The axial magnetic bearing (40) produces an axial magnetic field by means of a magnet coil (40) with a yoke iron (44) on the stator (14). An axially magnetized permanent magnet (50) is provided on the rotor (12), located approximately axially opposite the yoke iron (44). A permanently axially magnetized compensating magnet (54) is provided on the stator (14) and arranged axially opposite the permanent magnet of the rotor (50) and polarized in the opposite direction, whereby the permanent magnet (50) of the rotor and the compensating magnet (54) repel each other. In a centre position, the rotor is bias-free by compensating the forces of attraction between the permanent magnet of the rotor and the yoke iron. As a result, the centre position of the rotor can be adjusted with relatively small magnet coil flows.

Abstract: The invention relates to a magnetic bearing for rapidly rotating machines (1), in particular, for turbo compressors, drag vacuum pumps, or similar, comprising two bearings (3, 4), each with a stator magnetic-ring set (5, 7) and a rotor magnetic-ring set (6, 8) and means (31) for damping the rotor movement, preferably in a radial direction. According to the invention, the damping means may be simplified, whereby the magnetic bearing (3, 4) consists of magnetic-ring sets (5, 6; 7, 8) arranged concentrically to each other, in which the fixed magnetic-ring set (5 or 7) is arranged externally and the rotating magnetic-ring set (6 or 8) is arranged internally and the damping means (32, 54, 55) are connected to the outer circumference surfaces of at least one part of the magnetic ring of each of the stator-side magnetic-ring sets (5, 7) and is made from a non-magnetic, material with good electrical conducting properties.

Abstract: A friction pump (1), such as turbomolecular pump, includes a steel housing (2) in which a steel shaft (15) is supported by a bearing (16). A rotor (4) with a central bore (21) is mounted on the shaft. In order to reduce the risk of the joint area between the rotor and the shaft becoming loose, a ring groove (26, 31) which encompasses the joint area between the rotor is provided in an area adjacent at least one of the faces of the rotor. A reinforcing ring (34, 35, 38) of a high strength, low thermal expansion material encompasses one of a thrust member (28) and cylindrical rotor sections (32, 37) adjacent the shaft.

Abstract: A friction vacuum pump (1) with a frame (5), stator (3), rotor (4) and housing; all functional elements of the pump are combined into one unit (22), which, in turn, can be inserted into a housing (19, 55) that has been adapted to a specific application; using this procedure, all separate connection housing can be eliminated and optimal conductance can be achieved (FIG. 1).

Abstract: The invention relates to a friction vacuum pump (1) with a stator (3) and a rotor (4), which form at least two pump stages (12, 13, 14) with one gas inlet (23, 28) each, as well as with junction for the pump stages, which are equipped with junction openings (36,37) and serve for the connection of the gas inlets (23, 28) of the pump stages with devices to be evacuated; in order to avoid high conductance losses it is proposed that the junction openings (36, 37) are located in a plane which is disposed laterally adjacent to the pump stages (12, 13, 14) such that the distance between the junction openings (36, 37) and the rotor axis (15) is of minimum feasible size.

Abstract: The present invention relates to a friction vacuum pump having at least one turbomolecular pump stage (2) joined at its pressure side to a screw pump stage (4). In order to improve the pump properties it is proposed that a filling stage (3) be arranged between the turbomolecular pump stage (2) and the screw pump stage (4) that has blades (13) whose length corresponds at the suction side to the active length of the blades at the pressure side of the turbomolecular pump stage (2), and at the pressure side to the depth of the suction-side region of the screw (14) of the screw stage (4).

Abstract: A pressure for a chamber is regulated by controlling either the exhaust pressure at the exhaust side of a first vacuum pump or the internal pressure at a compression stage of the first vacuum pump, where the first vacuum pump is directly communicating with the chamber. The pressure of the chamber can be regulated by combinations of the following: controlling the variable rotational frequency of a roots vacuum pump, a pre-vacuum pump, or a high compression pump; controlling a control valve between a pre-vacuum pump and the first vacuum pump; controlling a control valve for injecting gas into the exhaust side of the first vacuum pump or into the compression stage of the first vacuum pump; and controlling a control valve or control valves for bypassing the first vacuum pump or a compression stage or compression stages of the first vacuum pump.