Abstract: A leak detection device has a test chamber which, for evacuation, is connected to an evacuation pump device. Moreover, the test chamber is connected by a test gas line to a test gas pump device. The test gas pump device is connected, at its main inlet, to a test gas detector, such that a detection of test gas can take place using the counter-current principle. A valve device is arranged in the test gas line. This valve device has a test gas chamber for temporary storage of test gas removed from the test chamber.

Abstract: A cold head for cryogenic machines comprises a displacer mounted in a working chamber of a housing. The cold head also has a high-pressure connection for supplying highly compressed refrigerant and a low-pressure connection for discharging expanded refrigerant. Also provided is a control valve arrangement for controlling the supply and discharge of refrigerant. According to the invention there is a bypass channel connecting the high-pressure connection to the low-pressure connection.

Abstract: A turbomolecular pump has a rotor element in a housing. The rotor element is arranged on a rotor shaft. The rotor shaft is supported by two bearing elements in the housing. The bearing element on the high-vacuum side is constructed as a roller bearing. In order to guarantee a pressure in the area of the bearing element that is acceptable for the bearing element constructed as a roller bearing, the bearing element is arranged in a chamber. The chamber is connected via a channel to the pre-vacuum area and sealed relative to the high-vacuum area by a gasket.

Abstract: A leak detection device has a test chamber which, for evacuation, is connected to an evacuation pump device. Moreover, the test chamber is connected by a test gas line to a test gas pump device. The test gas pump device is connected, at its main inlet, to a test gas detector, such that a detection of test gas can take place using the counter-current principle. A valve device is arranged in the test gas line. This valve device has a test gas chamber for temporary storage of test gas removed from the test chamber.

Abstract: A vacuum pump has the outer side of the pump housing provided with retaining elements. These serve to receive at least one mass element. With these mass elements, which are preferably arranged asymmetrically with respect to the longitudinal axis of the vacuum pump, vibrations that occur can be suppressed.

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 turbomolecular pump (12) has a circular intake opening (16) distal of an inlet rotor stage (18). The intake opening (16) comprises at least two opening sections (41, 42, 43) that are separated from each other.

Abstract: A vacuum device comprises a plurality of cryopumps (10) connected with one or a plurality of vacuum chambers. The cryopumps (10) are connected via media supply conduits (12) and media return conduits (14) with a compressor (16). An adjusting device (18) is connected before at least one of the cryopumps for controlling the amount of media fed to the cryopump. Further, the cryopumps (10) comprise a temperature measuring device. The temperature measuring device and the adjusting device (18) are connected with a controller (28). To allow the desired amount of media to be fed to the cryopumps (10), the adjusting device (18) comprises a throttle (24) in a media supply conduit (12) and a controllable valve in a throttle bypass conduit (22).

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.