Abstract: A high-speed turbomachine includes a magnetic bearing (22, 23) and a retainer bearing for mounting the rotor. The retainer bearing is embodied as a sliding bearing (26, 27) and encompasses a bearing shell (28) at the stator end, a bearing shaft (20) at the rotor end, and an intermediate bushing (30) between the bearing shell (28) and the bearing shaft (20). The intermediate bushing (30) is spaced apart from both the bearing shaft (20) and the bearing shell (28) by a circular gap (33, 34). The intermediate bushing (30) is rotatable relative to the bearing shell (28) and the bearing shaft (20). As a result of this design, the sliding bearing (26) is provided with two pairs of sliding surfaces, onto which all occurring dynamic forces are distributed such that wear is significantly reduced, thus allowing sliding bearings to be used as retainer bearings in a magnetically mounted high-speed turbomachine.

Abstract: A multi-inlet vacuum pump includes a first pump device (10) including a first rotor element (18) with a plurality of first rotor disks (20) serially arranged in the conveying direction (36), and a second pump device (12) including a further rotor element (26) with a plurality of second rotor disks (28) serially arranged in the conveying direction (36). A diameter of the second rotor disks (28) is at least partially larger than a diameter of the first rotor disks (20). A main inlet (32) sucks in a first fluid stream (34) with the first pump device (10). The first fluid stream (34) is conveyed in the direction of the further pump device (12). An intermediate inlet (38) sucks in a second fluid stream (40) with the second pump device (12). The second fluid stream (40) is conveyed in the direction of a pump outlet. A process of merging the two fluid streams (34,40) will occur within the second pump device (12), preferably between two adjacent second rotor disks (28) of the second pump device (12).

Abstract: A rolling-element bearing for bearing rotating components in vacuum devices includes a plurality of rolling elements (10) arranged between bearing elements (12, 14). A bearing compartment (26) is for example closed by sealing elements (22, 24) on both sides. The sealing elements (22, 24) have a minor sealing gap(s). The rolling-elements bearing is used in vacuum sections in which a pressure of less than 10?3 mbar prevails.

Abstract: A method for cleaning a vacuum pump (10) having a pump chamber (12) with at least one pump rotor (14) includes performing the steps of: a) filling a cleaning liquid (28) into the pump chamber (12), b) distributing the cleaning liquid (28) in the pump chamber (12), c) dissolving impurities with the cleaning liquid (28), d) draining the cleaning liquid (28) from the pump chamber (12).

Abstract: An overall leakage rate of a vacuum system which can be operated continuously or cyclically is determined. The vacuum system includes at least one process chamber (10) and a pumping device (16) connected to the process chamber (10). In a cyclical leakage rate determination technique, the following steps are taken: suppressing a process gas feed to the process chamber (10), feeding a carrier gas to the process chamber (10), conveying the carrier gas and a leakage gas using the pumping device (16), measuring an amount of a gas component in the pumped gas, and determining the overall leakage rate of the vacuum system based on the measured amount of the gas component.

Abstract: A stator-rotor arrangement for a vacuum pump, in particular for a turbomolecular pump, includes a plurality of stator disks (18) that cooperate with a rotor element (14). The stator disks (18) are disposed between rotor disks (16). The stator disks (18) are held by way of stator rings (20, 22). At least two of the stator rings (20) include protrusions (24) that are connected together by way of holding elements (28, 30). This makes pre-installation of the rotor-stator arrangement (12) or placement of the rotor-stator arrangement (12) in a housing (10) possible. The protrusions (24) are disposed in the area of corners (32) of the housing (10).

Abstract: A vacuum pump, in particular a pump of the type with rolling bodies, includes rotary bodies (12) arranged in a suction chamber (10). The pressure side (30) of the pump is connected to the suction side (20) by a connecting channel (22). In the connecting channel (22), a valve (24) is arranged which closes a through opening (32). On exceeding a set pressure difference between the pressure side (30) and the suction side (20), the valve opens automatically. In order to reduce the necessary space and to reduce the switching noise from the valve, the valve body is embodied as a valve flap (28).

Abstract: A vacuum pump, in particular a turbomolecular pump or a multi-inlet pump, includes a rotor shaft (12) that supports at least one rotor device (14). The rotor shaft (12) is mounted on the pressure side by way of a bearing arrangement (56) and on the suction side by way of a bearing arrangement (30). The suction-side bearing arrangement (30) is disposed in a high-vacuum area (22) and includes an electromagnetic bearing. Preferably, a coil (32) of the electromagnetic bearing is disposed in a recess (38) of a housing element (40). The recess (38) is pressure-encapsulated, in particular by a tubular closure element (42).

Abstract: A vacuum pump, particularly a turbomolecular pump or multi-inlet pump, comprises a rotor shaft (12) carrying at least one rotor means (14). The rotor shaft (12) is supported on the pressure side by a bearing assembly (56) and on the suction-side by a further bearing assembly (30). According to the invention, the suction-side bearing assembly (30) comprises an electromagnetic bearing (32,34). Further according to the invention, the pressure-side bearing assembly (56) comprises a ball bearing (58) so that the rotor shaft (12) can be given the largest possible length. The rolling bearing (58) is preferably biased by the electromagnetic bearing (32,34).

Abstract: A pump bearing arrangement, suitable particularly for rapidly rotating pumps such as turbomolecular pumps, comprises a pump rotor (10) con-nected to a rotor shaft. The rotor shaft (14) is supported in a shaft housing (20) by two bearing arrangements (12). Each bearing arrangement (12) has an inner bearing ring (16) connected to the rotor shaft (14) and an outer bearing ring (22) connected to the shaft housing (20). Bearing supports (24) are disposed between the two bearing rings. At least one vibration element (26) is provided between the outer bearing ring (22) and the shaft housing (20), serving for damping and further having a thermal conductivity of at least 0.3 W/mK for dissipating heat.

Abstract: A method for determining the fatigue of the pump rotor of a gas turbopump comprises the following method steps: continuous determination of the rotational speed (n) of the pump rotor, determination of the local rotational speed maxima and minima of a temporal rotational speed profile under consideration, association of the rotational speed maxima and minima with each other to form pairs, determination of a pair fatigue value (L) for each of the rotational speed pairs, and accumulation of all pair fatigue values (L) to form a total fatigue value (Ltot). In this manner it is possible to determine the cyclic stress for the pump rotor of a vacuum pump and to include it in the calculation of a total fatigue value.

Abstract: A rapidly rotating vacuum pump includes: a magnet-mounted rotor driven by an electric drive motor with a predetermined constant nominal rotational frequency (fnom). The rotor and a rotor bearing are embodied in such a way that the bending-critical counter-rotational resonance frequency (fcrit) is between 3% and a maximum of 30% above the nominal rotational frequency (fnom), thereby preventing an overspeed.

Abstract: The vacuum pump comprises a casing (10) closed by a vacuum cover (20). Between an end wall (14) of the casing (10) and the vacuum cover (20), a circuit board (16) is arranged for current feedthrough. The circuit board (16) is sealed by two sealing elements (15, 21) of different diameters so that an annular partial region (22) is on its outer side subjected to the atmospheric pressure and is on its inner side subjected to the vacuum. It is avoided that the circuit board (16) laterally projects beyond the contour of the casing (10).

Abstract: A turbomolecular pump (10) includes a rotor (18) which is mounted on a housing (12) by at least one roller bearing (16). The roller bearing (16) comprises a non-rotating bearing shell (20) and a rotating bearing shell (22). The non-rotating bearing shell (20) is mounted on the housing (12) by an elastic vibration ring (14). The vibration ring (14) is of an anisotropic form, such that the spring stiffness is inhomogeneous over the circumference.

Abstract: A multi-stage pump rotor (10) for a turbomolecular pump has at least two separate blade disk rings (17), each having a motor ring (12) and at least one blade disk (14). A cylindrical reinforcement pipe (18), which surrounds the rotor rings (12) of the blade disk rings (17) on the outside without clearance, is provided between the blade disks (14) of adjacent blade disk rings (17). The reinforcement pipe (18) absorbs a large part of the tangential forces occurring during operation such that the pump rotor (10) has improved stability at high rotor speeds.

Abstract: A vacuum line (10) includes two line parts (12, 13) connected by a vibration damper (14). The vibration damper (14) is formed by a vertical outer pipe (18) and a vertical inner pipe (20) spaced from the outer pipe (18). A flexible tension sleeve (30) is fastened between opening edges (19, 42) of the outer pipe (18) and the inner pipe (20). The tension sleeve establishes a vacuum-tight connection of opening edges (19, 42) of the outer pipe (18) and the inner pipe (20).

Abstract: The invention relates to a process for preparing rotors or stators of a turbomolecular pump with rotor blades made of a specific aluminum alloy.

Abstract: The invention relates to a vacuum pump in which the gas bearing is coated with a hard layer, and to a process for preparing such gas bearing of a vacuum pump.

Abstract: A vacuum pump (10) has a pump rotor (16), an active magnetic bearing (20,21), a safety bearing (22,23) associated with the magnetic bearing (20,21), an electric drive motor (18) having a motor stator having a plurality of stator coils (191,192,193) for driving the pump rotor (16), a brake relay (42) having a plurality of changers each having a base contact (62,63,64), a brake contact (44,45,46) and an operational contact (47,48,49), and a short circuit point (60) by way of which all brake contacts (44,45,46) of the brake relay (42) are directly connected to each other. All stator coils (191,192,193) are connected to the base contacts (62,63,64) of the changer, and can be connected directly to each other by way of the brake contacts (44,45,46) of the brake relay (42) and by way of the short circuit point (60), and can be connected to an inverter module (32) by way of the operational contacts (47,48,49).