Abstract: A ball bearing (1) has an inner race (2) and an outer race (3). In order to prevent the rotating parts from being damaged when the bearing assembly fails, the bearing has emergency bearing surfaces (14, 15) which are concentric to the rotational axis (6) and of which one is a part of the rotating bearing race and the other is a part of the fixed bearing race. During normal operation, the emergency bearing surfaces (14, 15) are situated opposite one another with a relatively narrow gap (24) therebetween. But, in the event of failure, the surfaces (14, 15) engage and function as emergency bearing surfaces.

Abstract: The present invention relates to a process for the coating of objects made of valve metals or their alloys with a thin barrier layer consisting of the metal and an oxide ceramic layer provided thereon whose surface has been coated with fluoropolymers, characterized in that the fluoropolymers are introduced into the capillary system of the oxide ceramic layer in the form of a solution by vacuum impregnation, followed by removing the non-wetting portions of the solution and drying.

Abstract: A multi-chamber installation (1) treats objects under vacuum. An evacuation system (5) is connected to a plurality of chambers (2, 3, 4). To reduce the complexity of the evacuation process, a forepump (5) has several stages (11, 12, 13). Each of said stages is connected to one of the chambers (2, 3, 4).

Abstract: A piston vacuum pump comprises a cylinder (14) and a piston (12) that forms a compression chamber (28) with the cylinder (14). The piston (12) oscillates in the cylinder (14) with a compression stroke and an intake stroke. In a side wall (16) of the cylinder (14), a gas inlet (30) is provided, the gas inlet (30) being closed by the piston (12) at the beginning of the intake stroke and open at the end of the intake stroke. Further, an equalizing conduit and a valve are provided through which gas from the gas inlet (30) flows into the compression chamber (28) at the beginning of the intake stroke. This provides a simple arrangement of an equalizing conduit with a valve. The piston substantially forms the equalizing conduit and the valve. Thereby, the valve can act in the region of the piston end wall so that the dead volume is minimized.

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 side channel pump, preferably a vacuum pump, includes a driven rotor (16) and a fixed stator (14). The rotor (16) and the stator (14) define a pump channel circulating in a peripheral direction. Blades are fixed onto the rotor, protruding into the cross-section of the pump channel. The pump channel also includes a blade-free side channel (44). The pump channel (22) containing the side channel (44) extends in a helical manner around the rotor (16). The pump channel is advantageously not limited to the length of a winding but can have the length of substantially any number of uninterrupted windings. As a result, a high suction performance and a high compression ratio in the pump can be obtained.

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 vacuum pump includes an inlet port (14) and an exhaust port (86, 88). Gas from an enclosure connected to the inlet port is pumped to the exhaust port by first and second rotors (18, 52, 254) which are mounted on first and second shafts (30, 60) extending through a pump chamber (112). The rotors are connected with shaft sections (140, 150, 240, 250) which include a lobe (142, 172, 242, 242?) extending from the shaft sections and a mating channel (152, 182, 252, 252?) defined in the other. The lobes matingly engage the channels during rotation of the rotors to form a suction section (154). The suction section (154) compresses a volume of gas entering the pump from the inlet port (14) reducing the power consumed to move the volume of gas through the pump chamber more easily and increase pump efficiency.

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 piston compressor comprises a piston (12) which oscillates in a cylinder (14). A compressed-gas supply arrangement is provided which comprises a compressed-gas accumulator (34), a compressed-gas supply line (18) between a compressed-gas source (20) and the compressed-gas accumulator (34). Further, the compressed-gas supply line (18) comprises an inlet valve (42) which is open when the piston (12) is in a filling position. The inlet valve (42) is defined by a cylinder wall opening (22) and a piston wall opening (38) which are located opposite each other when the piston (12) is in the filling position, thus defining an open valve, and which are closed by the piston wall (40) and the cylinder wall (24), respectively, when the piston (12) is in the non-filling position, thus defining a closed valve. Thereby, a valve is provided which does not comprise any moving parts and is thus easy to manufacture, is highly reliable and has a long service life.

Abstract: A ball bearing (1) has an inner race (2) and an outer race (3). In order to prevent the rotating parts from being damaged when the bearing assembly fails, the bearing has emergency bearing surfaces (14, 15) which are concentric to the rotational axis (6) and of which one is a part of the rotating bearing race and the other is a part of the fixed bearing race. During normal operations the emergency bearing surfaces (14, 15) are situated opposite one another with a relatively narrow gap (24) therebetween. But, in the event of failure, the surfaces (14, 15) engage and function as emergency bearing surfaces.

Abstract: A friction vacuum pump (1) comprises a fixed element (7) bearing rows of stator blades (3) and a rotating element (6) bearing rows of rotor blades (2). The rows of stator blades and rotor blades are arranged concentrically with respect to an axis of rotation (4) of the rotating element (6) and mesh with each other. In order to create in the axial direct a short friction pump, the elements (6, 7) bearing the rows of rotor blades and stator blades extend in a substantially radial manner and the longitudinal axes of the blades (2, 3) extend in a substantially axial manner.

Abstract: A vacuum pump (10) includes a control device (20) for processing operational data and operational instructions. Further, the vacuum pump (10) includes a touch screen (40) serving as display for displaying the operational data callable from the control device (20) and as input for inputting operational instructions into the control device (20). The touch screen (40) includes a display panel (42) and a key panel (44) as display and the input, respectively, and is connected with the control device (20) via a data line (36). By combining the display and the input in a single device, namely the touch screen, the trouble for display and data input is reduced.

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: Two-shaft vacuum pumps are normally driven by asynchronous motors. The asynchronous motor rotors configured as cage rotors are relatively heavy and long and must therefore be supported by supporting bearings. It is an object of the invention to provide a two-shaft vacuum pump with a simplified drive motor. The two-shaft vacuum pump (10) according to the invention comprises a synchronous motor as a drive motor (20), wherein the motor rotor (26) is permanently excited. Permanently excited motor rotors (26) are smaller and of lighter weight such that rotor supporting bearings can be omitted. Thus, the problems associated with cooling and lubrication of the supporting bear-ings are eliminated either.

Abstract: The invention relates to a chamber for the detection of leaks on foils (1). Said chamber comprises two frames (2, 3) which are connected together in an articulated manner, foils (4, 5) which are mounted on said frames, a test chamber (8) composed of the foils, a seal (12, 13, 18) arranged between the frames and at least one bore hole (7), preferably several bore holes, in at least one of the two frames (2, 3), which can be connected to the inlet of a vacuum pump (15, 16, 22). In order to improve the chamber's closing features, said chamber comprises an edge zone (14) wherein a vacuum can be created independently of the test chamber (8) and into which said bore holes (7) open out.

Abstract: A vacuum pump (1, 30) has an inlet (5) and an outlet (6). Plug-in screw fittings (9) are connected with the inlet and the outlet. The plug-in screw fittings include a bore with an internal bevel (22) that receives a flexible connecting line (23), a chuck collet (19), and an O-ring (21) frictionally in a vacuum-tight relationship. In this manner, a more simple and versatile connection is provided between the vacuum pump and the connecting lines.

Abstract: A pump (1) is provided with a housing (2), having an inlet (28) and an outlet (29), a drive (5), a fixed cylinder (2) centered on a mid-axis (9), a displacer (18), rotating eccentrically within the cylinder (2), a crank drive (13) for the displacer (18), a circumferential sickle-shaped pumping chamber (26) between the cylinder (2) and displacer (18) and a helical sealing element (27, 27?, 27?, 39) in the pumping chamber (26). The pump is a dry vacuum pump, whereby the displacer (18) circulates in the cylinder (2) without making contact.

Abstract: The invention relates to a magnetic bearing having a fixed first bearing portion and a movable second bearing portion which is contactlessly supported on the first bearing portion. The first bearing portion (12) comprises a magnetic coil (42) generating a magnetic field and having a yoke (44). The second bearing portion (18) comprising a permanent magnet (50) which is magnetized in alignment with the yoke (44). The permanent magnet of the second bearing portion has an attracting effect upon the yoke of the first bearing portion. To avoid this, the first bearing portion is provided with a permanently magnetized compensation magnet (54) which is located opposite the permanent magnet (50) of the second bearing portion (18) and is magnetized oppositely to the permanent magnet (50).

Abstract: A turbomolecular vacuum pump (1) has an inlet (3) and an outlet (4) and rotor and stator vanes (5 and 6), situated between the inlet and outlet. The rotor vanes (6) have front sides (11) and rear sides (12) in relation to the direction of rotation. At least a part of the rotor vanes (6) have a rear side (12) which is convex on the suction-side and concave on the delivery side. Alternately, at least part of the rotor vanes (6) have a front side (11), which is concave on the suction side and convex on the delivery side.