Abstract: A vacuum pump includes a housing having an inlet port and an exhaust port, at least one molecular drag stage within the housing, the molecular drag stage including a rotor and a stator that defines a tangential flow channel which opens onto a surface of the rotor, and a motor that rotates the rotor so that gas is pumped from the inlet port to the exhaust port. The stator defines one or more obstructions in the channel. The obstructions alter gas flow through the channel and produce turbulence under viscous or partially viscous flow conditions.

Abstract: An oil mechanical vacuum pump, which is equipped with an electric motor comprises an electronic control device for supplying the electric motor with power. The electronic control device comprises a frequency converter for controlling the excitation frequency Fecc of the voltage signal SU by which the motor is powered as a function of at least one operating parameter of the pump and of at least one threshold value that can be modified depending on the operating conditions of the pump.

Abstract: A device and a method provide a detection of a presence of a test gas. The device comprises a vacuum chamber connected to a vacuum pump equipped with an electronic power supply unit. At least one portion of the chamber is separated from a surrounding outside environment by a membrane selectively permeable to the test gas. A gas flow from the outside environment is guided forcefully over the surface of the membrane via a flow conveyor, which comprises an inlet duct, a diffuser and an outlet duct. The presence of any test gas is detected by the changes in the electrical current to the vacuum pump provided by the power supply.

Abstract: An oil rotary vacuum pump of mechanical type (100) is filled with a requested amount of oil at the end of the manufacturing process, then it is stored and then shipped to the user, letting the user to avoid an operation of introducing the proper amount of oil into the pump. The oil leakage is prevented by securing the suction and/or exhaust ports (3, 17) of the pump, which are sealed by means of a removable sealing member, for instance by means of a membrane (21, 23).

Abstract: A support ring (1) for rolling bearings (11), especially for rolling bearings applied to rotors with very high rotation speed, such as rotors of rotary vacuum pumps, the ring comprising a pair of concentric cylindrical shells (3, 5) connected together by a plurality of oblique radial plates (9), at least one of said shells (3, 5) being circumferentially broken so as to define a plurality of shoes (7), each shoe being connected to at least one of the radial plates (9) in such a manner as to define shoe portions or arcs (A1, A2) of different length, wherein the plates (9) are resilient and allow for the radial displacement of the shoes (7) so as to restrain vibrations of the rotating portion.

Abstract: A compact turbomolecular vacuum pump (1) is driven by a cup-type motor (8). The cup-shaped rotor of the motor is preferably integrated into the pump rotor (14) and may define corresponding pumping stages, for instance Holweck stages, wherein the stators (11, 12) of said stages being preferably obtained by superimposing stator rings (11?, 12?).

Abstract: A pressure sensor made of a wafer with a pair of parallel silicon layers and a silicon oxide layer there between, comprises a vibrating microassembly formed as a silicon beam, which is arranged in a plane perpendicular to the silicon layers and fastened to a supporting base. A control devise is formed from a portion of one of the silicon layers and is driven by a signal of a predetermined frequency component, which under absolute vacuum conditions makes the microassembly to freely oscillate at a known frequency and amplitude relative to the supporting base within a cavity formed by removing the silicon oxide layer. An optical detection system detects deviations of the frequency and/or amplitude of oscillation of the microassembly from the known frequency and/or amplitude.

Abstract: A gas-selective permeable membrane (1) utilisable in a leak detector for a gas, more particularly helium, comprising a sheet-like body (11) on which at least one reduced thickness area (15) is defined by removing a material from the sheet-like body. This at least one reduced thickness area (15) being permeable to at least one gas and formed so as that it is partly surrounded by a thicker and substantially gas-impermeable area (16) ensuring the structural strength of the membrane.

Abstract: A process for manufacturing stators of vacuum pumps, and stators obtained thereby, wherein a plurality of stator discs or rings are formed, preferably by pressing, and then stator discs or rings are coaxially stacked and mutually rotated so as to form a stator surface having defined thereon at least one groove extending in substantially axial direction with respect to a body of the stator.

Abstract: A micro-electro-mechanical vibrating pumping stage comprises a silicon substrate (15) on which there are formed a single-layer or multilayer oscillating assembly (27; 127; 227; 327) with a vibrating membrane and a device controlling the membrane in order to provide its oscillation with respect to the substrate. A molecular vacuum pump incorporates this vibrating pumping stage.

Abstract: A leak detector comprises a high vacuum envelope connected with a vacuum pump to bring the vacuum envelope to a pressure sensibly lower than ambient pressure. At least a portion of the envelope is separated from an external environment through a quartz membrane associated with an electrical resistor, which heats the membrane to a sufficient temperature in order to make it permeable to a corresponding test gas (in particular, helium). In operation, an electronic control unit detects variations in the current absorbed by the vacuum pump and consequently signals the test gas diffusion into the chamber and hence the existence of a leak. A sampling line with a sampling pump disposed therein is connected to a probe for the intake of gas directed to expose to the membrane. The gas is discharged to the outside through a discharge line. A system for switching between the gas intake and exhaust is provided, in order to quickly eliminates any test gas trace from said detector.

Abstract: A pressure sensor is a micro-electro-mechanical vibrating device, with a silicon substrate (15; 15?) onto which a single-layer or multilayer vibrating assembly (121; 221; 321) is formed. It comprises an electrode (21; 21?), which makes the assembly to oscillate relative to the substrate at the resonance frequency or at another known frequency, and a detector for detecting the actual frequency and/or amplitude of said oscillation. The actual frequency and/or amplitude are affected by the conditions, in particular the pressure, of the external environment and the variations of the frequency and amplitude with respect to the values set by the electrode is used to measure pressure variations in the surrounding environment.

Abstract: An ionisation vacuum gauge for measuring the residual pressure of a gaseous material remaining in a container (10), more particularly after operation of a vacuum pump comprises an electron-emitting cathode (31) made by exploiting the nanotube technology, a grid (13; 33; 133; 133?) for accelerating the electrons emitted by the cathode, and a plate (15; 35) collecting the ions and/or the ionised positive molecules of the gas. Measuring the plate current by a galvanometer allows for determining the value of the residual pressure inside the container.

Abstract: The present invention relates to an ionisation vacuum gauge for measuring the residual pressure of a gaseous material remaining in a container (10), more particularly after operation of a vacuum pump. The gauge comprises an electron-emitting cathode (17), a grid (13) for accelerating the electrons emitted by the cathode and a plate (15) collecting the ions and/or the ionised positive molecules of the gas, wherein said plate is placed outside said grid. Measuring the plate current by a galvanometer allows determining the value of the residual pressure inside the container.

Abstract: A pumping stage for a vacuum pump, has an improved geometry allowing an optimum trade-off to be achieved between the exhaust pressure and the pumping rate attained in that stage. In the pumping stage (1) the axial extension that is the height of the pumping channel (3) varies along the circumference of the channel (3) between the inlet port (13) and the outlet port (15).

Abstract: A turbine pump has a transition chamber (9), which separates a low-pressure section (1B) from a high-pressure section (1A) and into which an additional inlet port (5) opens. The chamber (9) is defined by a stator stage (10) consisting of a disc (11) with a peripheral edge (12), integral with said disc (11) and forming a spacer ring integrated into the stator stage, and with radial blades (17) joined with the disc (11) at both ends.

Abstract: A turbomolecular vacuum pump (5) comprises a first pumping section (1) having pumping stages with bladed rotor discs, a second pumping section (2) having pumping stages with smooth rotor discs, a third pumping section (3) having a pumping stage with a toothed rotor disc (26), and a fourth pumping section (4) of the ejector or venturi pump type. (FIG.

Abstract: The method uses electrical discharge machining to form, onto a disc (8) belonging to a stator (11) of a turbine pump, radial blades (12) joined to the disc at both ends and separated by very narrow channels (13). To form the blades, a workpiece (2) is exposed to a tool (1) having a circular edge (4) whose radius corresponds with an external radius of the blades. The tool is provided along its edge with at least one tongue-shaped elongated member (5) joined at one end to the tool plate (3) and extending along said edge (4) in an inclined plane. Due to a relative combined rotation and translation motion between the tool and the workpiece, at least one channel (13) with shape, size and inclination corresponding with those of the tongue element (7) is produced in the workpiece.

Abstract: The present invention relates to an improved helium detecting unit particularly adapted to be used under difficult conditions and in places without power supply sources, which comprises an electronic processing stage [means] [implementing the task of] for calculating the helium concentration in the gas mixture to be sampled and an electronic controlling stage [means] for controlling the detecting unit, and wherein there is provided a sampling chamber, coated with a reflecting material and provided with a gap, mounting a sinterized filtering member adapted for cooling the sampled gas flow coming out of a sucking sampling pump equipped with a filter against the impurities.

Abstract: An improved electronic device allows for the feeding of an ion pump with a plurality of voltages that are changed as a function of the current drawn by the pump and therefore of the pressure value within the pump.