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 vacuum pump (10) comprises at least one rotor shaft (12) having a rotor section (14) with a rotor (16), a bearing section (18) with a bearing (20), and a shaft sealing system (22) that is axially situated between the rotor section (14) and the bearing section (18). The shaft sealing system (22) axially comprises, on the side of the rotor, a gas seal (32) and, on the side of the bearing, an oil seal (34). The shaft sealing system (22) additionally comprises, between the gas seal (32) and the oil seal (34), a separating chamber, which surrounds the rotor shaft (12) and is ventilated by at least one separating chamber ventilation duct (60, 62). This enables the pressure difference that decreases via the gas seal and the pressure difference that decreases via the oil seal to be adjusted. An appropriate adjustment can prevent oil on the bearing side from passing through the oil seal toward the separating chamber.

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 (10) comprises at least one rotor shaft (12) having a rotor section (14) with a rotor (16), a bearing section (18) with a bearing (20), and a shaft sealing system (22) that is axially situated between the rotor section (14) and the bearing section (18). The shaft sealing system (22) axially comprises, on the side of the rotor, a gas seal (32) and, on the side of the bearing, an oil seal (34). The shaft sealing system (22) additionally comprises, between the gas seal (32) and the oil seal (34), a separating chamber, which surrounds the rotor shaft (12) and is ventilated by at least one separating chamber ventilation duct (60, 62). This enables the pressure difference that decreases via the gas seal and the pressure difference that decreases via the oil seal to be adjusted. An appropriate adjustment can prevent oil on the bearing side from passing through the oil seal toward the separating chamber.

Abstract: The invention relates to a screw vacuum pump, comprising two shafts (7, 8), each bearing a rotor (3, 4) containing a hollow chamber (31). Said chamber (31) contains a second hollow chamber (32) which embodies a component of a coolant circuit. The shafts (7, 8) have open bores (41) on the delivery side, through which the coolant is supplied and evacuated to or from the additional hollow chambers (32). In order to improve the effectivity of the cooling of the rotors, guide components (44) are located in the open bores (41) of the shafts (7, 8). Said guide components separately guide the inflowing and outflowing coolant.

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 screw vacuum pump (1) has shafts (7, 8) and rotors (3, 4) secured to the shafts. Each rotor has a central hollow chamber (31) which receives the shaft or contains in built-in components rotating along with the rotor to define a relatively thin annular slot segment (32) for cross-flow circulation of coolant. The annular slot segment is disposed between the built-in components and an inner wall of the rotor's hollow chamber and between a suction side and a delivery side of the rotor. Separate feed and discharge lines (41, 55, 63, 77, 78, 81, 89, 99, 101, 103) circulate the coolant through the annular slot segment in such a way that the coolant remains cavitation-free and bubble-free.

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).

Abstract: A process for operating a dry-compression vacuum pump with at least one pump chamber and at least one rotor driven by an electric motor, and to a vacuum pump suitable for this operating process. To reduce operational shutdowns for maintenance purposes without any risk to the pump, it is proposed that application-specific phenomena leading to deviations from the normal operating status or their effects be monitored and, after a predetermined deviation quantity has been attained at which operation of the vacuum pump could be adversely affected in future, steps be taken to remove the causes thereof.

Abstract: A process for operating a dry-compression vacuum pump with at least one pump chamber and at least one rotor driven by an electric motor, and to a vacuum pump suitable for this operating process. To reduce operational shutdowns for maintenance purposes without any risk to the pump, it is proposed that application-specific phenomena leading to deviations from the normal operating status or their effects be monitored and, after a predetermined deviation quantity has been attained at which operation of the vacuum pump could be adversely affected in future, steps be taken to remove the causes thereof.

Abstract: A method of operating a claw-type vacuum pump with two or more stages, each of which has a suction chamber with a pair of claw rotors and end-located suction and discharge ports. To avoid the possibility of liquids affecting operation of the pump, the invention proposes that the pump is operated without internal compression and that the gases emerging from at least one stage are cooled.

Abstract: A muffler arrangement includes a muffler with an essentially cylindrical housing having a face end with a central entrance opening and at least one exit opening arranged other than centrally on the face end. Baffles are disposed within the housing, the baffles being concentrically arranged pipe cylinders which extend alternatingly into one another and are closed at one end, for effecting a multiple deflection of gases traveling from the central entrance opening to the at least one exit opening. A coupling structure is secured to the muffler housing, for carrying the muffler in an operating position. The coupling structure has a central passage for connecting the muffler to an exhaust outlet of a machine, and has an other than central channel, surrounding the central passage, for connection to an exhaust gas output conduit for outputting exhaust gases from the muffler arrangement.

Abstract: Dry-running twin-shaft vacuum pump (1) with at least one pumping chamber (11, 12, 13), with a rotor pair (4-5, 6-7, 8-9) situated in the pumping chamber and borne by the shafts, and with a drive housing (21); in the pumping of toxic media, to limit the contaminated areas to components that are easy to assemble it is proposed that between the drive housing (21) and the adjoining pumping chamber (13) an intermediate plate be provided, which is traversed by the shafts (2, 3), contains the laterally exiting exhaust duct (52), and is releasable from the wall (17) of the drive housing (21).

Abstract: The invention relates to a method for the operation of a multi-stage, dry compression vacuum pump (1) with an inlet (7) and an outlet (9), in which the aspirated gases contain gaseous components which endanger the operation of the vacuum pump; in order to render the gas components harmless it is proposed that the gases aspirated from the vacuum chamber (8) and flowing through the vacuum pump be carried through a reaction chamber (14) in which the components endangering the vacuum pump are chemically or physically treated at a pressure between the aspiration pressure and the outlet pressure of the vacuum pump.

Abstract: A twin-shaft vacuum pump having a pair of shafts, at least one pump chamber, a pair of rotors disposed in the or in each pump chamber and mounted on the shafts, and housing members defining the pump chamber or chambers, a synchronization mechanism composed of two gears disposed in a side chamber, a drive motor, and a transmission mechanism connecting the drive motor to one of the shafts. In order to simplify installation and servicing of the pump, the shafts are mounted vertically. The side chamber, synchronization mechanism, and transmission mechanism are disposed below the lower rotor pair.