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: The invention relates to vacuum pump components without conversion layers that are made of valve metals and alloys thereof.

Abstract: The invention relates to a process for the coating of objects made of valve metals selected from aluminum, magnesium, titanium, niobium and/or zirconium and their alloys with an oxide ceramic layer formed from the metal which has a thin barrier layer as a boundary layer towards the metal whose surface has been coated with polymers, characterized in that said polymers are introduced into the capillary system of the oxide ceramic layer in the form of dimers or halogenated dimers of general formula I wherein R1 represents one or more hydrogen or halogen residues; each R2 represents hydrogen or halogen; and R3 commonly represent a corresponding xylylene residue for completing a dimeric structure; by vacuum coating, followed by polymerizing the dimers.

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 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: 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: 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 rotors or stators of a turbomolecular pump with rotor blades made of a specific aluminum alloy.

Abstract: The invention relates to a process for the coating of objects made of valve metals selected from aluminum, magnesium, titanium, niobium and/or zirconium and their alloys with an oxide ceramic layer formed from the metal which has a thin barrier layer as a boundary layer towards the metal whose surface has been coated with polymers, characterized in that said polymers are introduced into the capillary system of the oxide ceramic layer in the form of dimers or halogenated dimers of general formula I wherein R1 represents one or more hydrogen or halogen residues; each R2 represents hydrogen or halogen; and R3 commonly represent a corresponding xylylene residue for completing a dimeric structure; by vacuum coating, followed by polymerizing the dimers.

Abstract: A mechanical vacuum pump includes a rotor made of a light metal alloy by powder metallurgy. The powder metallurgy increases the resistance of the rotor to heat and creep.

Abstract: A mechanical kinetic vacuum pump with a stator (1), a rotor (6, 7) made from an aluminum or magnesium alloy and a rotor (6, 7) and a bearing shaft (3). The shaft (3) and the rotor (6, 7) are connected by a shrink- or screw-fit in a secure permanent connection. The rotor (6, 7) is made by spray forming. The main alloying component in the aluminum or magnesium alloy is silicon which is present in an amount such that the alloy has an expansion coefficient which essentially corresponds to the expansion coefficient of the shaft material.

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 mechanical kinetic vacuum pump with a stator (1), a rotor (6, 7) made from an aluminium alloy and a rotor (6, 7)-bearing shaft (3), whereby the connection between shaft (3) and rotor (6, 7) is a shrink- or screw-fit. According to the invention, a permanent connection between rotor and stator may be secured, whereby the rotor (6, 7) is made from an aluminium alloy produced by spray forming, the main alloying component of which is silicon and which has an expansion coefficient which essentially corresponds to the expansion coefficient of the shaft material.

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 mechanical kinetic vacuum pump comprising a rotor made of an alloy. The aim of the invention is to increase the resistance thereof to heat and creep. The rotor material is a light metal alloy produced from a powder metallurgical light metal alloy.