Abstract: A screw-type vacuum pump (1) is tempered such that characteristics of the pump are not substantially altered when the pump is subjected to thermal stress. In order to achieve said aim, cooling is adjusted according to an operating state of the screw-type vacuum pump (1), preferably to maintain a substantially constant pump gap (4).

Abstract: A screw-type vacuum pump (1) includes a pump housing (2, 6) with rotors (3, 4). A liquid cooling system cools the rotors and a drive motor (9). In order to improve the cooling of said pump, an external air-flow impelled cooling system is also provided for the pump housing (2, 6).

Abstract: A vacuum pump (1) comprising a pump chamber casing (5) accommodating two co-operating rotors (2, 3) which are respectively arranged on a shaft (8, 9). A bearing/gear chamber (6) is disposed adjacent to the pump chamber casing (5) in which the rotor shafts (8, 9) are cantilevered and provided with a synchronisation gear (17). A drive motor (25) whose drive shaft (28) extending parallel to the rotor shafts (8, 9) and is provided with a drive gear (35). A gear stage (37) is disposed between the drive shaft (28) and one of the rotor shafts (8, 9). In order to provide a machine of this type which can be embodied in a compact form, the drive gear (35) of the drive shaft (28) engages directly with a driven gear (36) on one of the rotor shafts (8, 9), forming the gear stage (37).

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: A screw-type vacuum pump (1) is tempered such that characteristics of the pump are not substantially altered when the pump is subjected to thermal stress. In order to achieve said aim, cooling is adjusted according to an operating state of the screw-type vacuum pump (1), preferably to maintain a substantially constant pump gap (4).

Abstract: A screw-type vacuum pump (1) includes a pump housing (2, 6) with rotors (3, 4). A liquid cooling system cools the rotors and a drive motor (9). In order to improve the cooling of said pump, an external air-flow impelled cooling system is also provided for the pump housing (2, 6).

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 vacuum pump (1) comprising a pump chamber casing (5) accommodating two co-operating rotors (2, 3) which are respectively arranged on a shaft (8, 9); a bearing/gear chamber (6) adjacent to the pump chamber casing (5) in which the rotor shafts (8, 9) are cantilevered and provided with a synchronisation gear (17); a drive motor (25) whose drive shaft (28) extends parallel to the rotor shafts (8, 9) and is provided with a drive gear (35); also comprising a gear stage (37) between the drive shaft (28) and one of the rotor shafts (8, 9). In order to provide a machine of this type which can be embodied in a compact form, the drive gear (35) of the drive shaft (28) engages directly with a driven gear (36) on one of the rotor shafts (8, 9), forming the gear stage (37).