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 vacuum pump arrangement, especially a turbomolecular pump arrangement, comprises a rotor (14) and a stator (16) in a pump housing (10). The pump housing (10) is connected to a vacuum chamber housing (26) through a pump flange (10). Retaining elements (34) are provided for this connection. To avoid a twisting of the retaining elements (34) in the event of a damage, such as the blocking of the rotor (14) and the high moments occurring thereby, the retaining element (34) comprises an anti-twist structure (40) cooperating with the vacuum chamber housing (26).

Abstract: A turbomolecular pump (10) comprises a stator (12, 18), a pump rotor (20) a motor (28) for driving the pump rotor and a control device (42). The control device (42) controls the motor output power such that the motor output power does not exceed a permissible maximum motor output power. On the stator side of the turbomolecular pump (10), temperature sensors (32–38) for measuring the stator temperature are arranged. The control device (42) comprises a maximum output power detecting device (50) that determines the permissible maximum motor output power in dependence on the measured stator temperature. Thus, the permissible maximum motor output power is not set to a constant value but always fixed in dependence on the current, measured stator temperature. Thereby, the capacity of the motor can be fully utilized as long as the measured stator temperature lies below a maximum value.

Abstract: A turbomolecular pump (10) comprises a stator, a pump rotor, a motor (28) for driving the pump rotor and a control device (42). The control device (42) controls the motor output power such that the motor output power does not exceed a permissible maximum motor output power. On the stator side of the turbomolecular pump (10), temperature sensors (32-38) for measuring the stator temperature are arranged. The control device (42) comprises a maximum output power detecting device (50) determining the permissible maximum motor output power in dependence on the measured stator temperature. Thus, the permissible maximum motor output power is not set to a constant value but always fixed in dependence on the stator temperature. Thereby, the capacity of the motor can be fully utilized as long as the measured stator temperature lies below a maximum value.

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).