Abstract: A technique of generating a flow from a gas. The technique includes the steps of selecting molecules from the gas on a nanoscopic or microscopic scale, and generating the flow from the selected molecules. The gas can be air. In one embodiment, the molecules are selected based on the direction of movement of the molecules. In another embodiment, the molecules are selected based on the velocities (i.e., direction and speed) of the molecules. Also, devices that implement the technique.

Abstract: A multi-staged boundary layer engine and process cell, (based on the effect known as adhesion and viscosity) which achieves high thermal efficiencies and high mechanical power output for use in the power generation, geothermal, energy recovery, solar, transportation, hydrogen production, desalinating water and hydroelectric fields. The design is novel with a dovetail attachment of the disc packs, allowing lower stress and allowing the use of next generation materials such as ceramics, composites and nanocomposites to improve the maximum temperature and the maximum RPM of the engine, thereby producing more horsepower and torque. In addition, this invention includes multi-stage vacuum, an external combustion chamber and condenser stages to improve the vortex flow through the primary disc pack cell. This engine will also encompass a closed loop cycle for ultimate efficiencies.

Abstract: A very safe and reliable turbo-molecular pump has been developed so that if an abnormal condition should develop on the rotor structure, it will not lead to damage to the stator or pump casing to cause a loss of vacuum in a vacuum processing system. The turbo-molecular pump has a pump casing housing a stator and a rotor therein, a vane pumping section and/or a groove pumping section formed by the stator and the rotor, and a constriction releasing structure for releasing the constriction of at least a part of the stator when an abnormal torque is applied to the stator by the rotor.

Abstract: A heteroscopic turbine with a Knudsen number of less than ten. In one embodiment, the heteroscopic turbine generates a flow from a gas. The turbine includes at least a moving surface and a plurality of turbine blades on or in said surface. Each of the blades has a height comparable to a mean free path distance that characterizes molecules in the gas, and the blades are spaced apart by a distance comparable to the mean free path distance. In operation, the surface moves such that the turbine blades pass through the gas at a speed comparable to the mean thermal velocity. In different embodiments, the turbine can perform filtering of molecules in the gas based on direction and/or speed (velocity). Also, techniques by which such a turbine operates.

Abstract: A turbo-molecular pump of high safety and reliability was presented, so that if an abnormal condition should develop on the rotor side, it will not lead to any damage to the stationary portions such as the stator or pump casing to cause loss of vacuum in a vacuum processing system. The turbo-molecular pump includes a rotor; a stator assembly surrounding the rotor; and a casing portion surrounding the stator assembly, wherein at least a partial clearance is formed between the stator assembly and the casing portion, so that, when an abnormal torque is applied from the rotor to the stator assembly, direct impact transmission is prevented from the stator assembly to the casing portion.

Abstract: An impeller system for use in a molten metal pump, the impeller system including a generally cylindrical outer wall with outlets therein, an impeller lid mounted on the impeller walls, the impeller lid including a plurality of inlets, with the shaft being mounted directly into a base, which is mounted relative to the outer wall. The impeller system has an open interior defined by the outer wall, the lid and the base, and the impeller shaft mounts directly into the base without the need for a collar or attachment to the impeller lid.

Abstract: A vacuum pump has a pump case having a gas suction port at an upper part of the pump case and a gas exhaust port at a lower part of the pump case. A stator column extends from a base of the pump case and has an outer circumferential surface. A rotor shaft is rotatably supported in the pump case by the stator column. A spacer is removably integrally connected to the outer circumferential surface of the stator column. The spacer has an outer circumferential surface spaced apart from an inner circumferential surface of the rotor and a through-hole extending form the outer circumferential surface to an inner circumferential surface thereof. A connecting member extends through the through-hole of the spacer and contacts the outer circumferential surface of the stator column to thereby removably integrally connect the spacer to the outer circumferential surface of the stator column.

Abstract: A vacuum pump has a pump case having a gas suction port at an upper surface thereof, a rotor shaft mounted in the pump case for undergoing rotation, and a rotor connected to the rotor shaft for rotation therewith. The rotor has inner and outer circumferential surfaces coated with a corrosion-resistant film treated by nonelectrolytic plating. Rotor blades are disposed in the pump case and are integrally connected to the outer circumferential surface of the rotor. Stator blades are integrally connected to the pump case so that the rotor blades and the stator blades are alternately positioned and arranged. A balancing body is disposed on the inner circumferential surface of the rotor for balancing the rotor during rotation thereof.

Abstract: A friction vacuum pump (1) has at least one turbomolecular pump stage (6, 7) with a molecular pump stage (12, 13, 15) that is subsequently connected on the pressure side (3), and with a transition stage (23) mounted between the turbomolecular pump stage and the molecular pump stage. In order to improve the transition from the turbomolecular zone to the molecular zone, the transition stage has a flow section that is continuously tapered in the tangential by limiting surfaces (27, 28).

Abstract: There is provided a rotor for a turbo/drag vacuum pump, the rotor comprising an upstream rotor segment of the turbine type made of metal or alloy, and a downstream rotor segment of Holweck type made of composite material. The downstream segment of the rotor has a reinforcing structure made of long fibers that are distributed in a manner that varies as a function of the section under consideration: in the annular connection region connected to the upstream segment of the rotor, the fibers are inclined and/or spaced apart in order to conserve sufficient flexibility for the composite material to enable it to deform so as to track deformation of the metal of the upstream rotor segment while it is in operation; in contrast, the fibers are close together and form turns that touch in the downstream region of the skirt, thereby guaranteeing greater stiffness in order to withstand the mechanical stresses that occur during high-speed rotation of the rotor in operation.

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: In a vehicle alternator having a stator, a rotor, and frames, a disc group is fixed to an axial end surface of a magnetic pole core of the rotor for creating the flow of cooling air. The disc group includes a plurality of discs layered with gaps between them. The disc group is disposed rotatable with the rotor. When the disc group rotates with the rotor, cooling air flows in a radially outward direction along the disc surfaces.

Abstract: A vacuum pump has a rotor mounted to undergo rotation about a rotational axis. A cylindrical base member surrounds a lower outer periphery of the rotor. A cylindrical pump case surrounds an upper outer periphery of the rotor. The base member has an inner periphery, an outer periphery, and a groove formed between the inner and outer peripheries thereof. The pump case is connected to the base member so that a portion of the outer periphery of the base member confronts a portion of the inner periphery of the pump case. A thread groove is formed in the inner periphery of the base member.

Abstract: A turbo-molecular pump has a main body and a pump case for covering the main body. A first flange is integrally formed with the pump case for connection to a second flange integrally with a vacuum chamber. The flange of the pump case and the flange of the vacuum chamber are integrally connected together with fastening bolts. A clamping structure separately clamps the first and second flanges together by surrounding a portion of each of the first and second flanges.

Abstract: Vibrations generated by a vacuum pump are prevented from propagating to external equipment such as an electron microscope. A casing (a separate casing portion and a casing main body) that houses a stator, stator blades, a rotor portion, and rotor blades as an exhaust function portion is connected to an inlet port portion in which an inlet port for sucking in a gas from the outside is formed, through an elastic member. An suction space between the casing and the inlet port portion is sealed by a bellows cylinder sealing means, and motion regulating members and motion regulating members and which regulate the amount of separation between the inlet port portion and the casing, and change shape due to relative motion between the two, are formed between the inlet port portion and the casing.

Abstract: A molecular pump for exhausting a chamber has a casing, a stator mounted in the casing, and a rotor mounted in the casing for undergoing rotation relative to the stator during exhaustion of the container. The rotor has a surface disposed opposite to and confronting a surface of the stator. A thread groove is formed in at least one of the opposite and confronting surfaces of the stator and the rotor. A clearance varying device varies a magnitude of a clearance between the opposite and confronting surfaces of the stator and the rotor. An exhaust controlling device controls a degree of exhaustion of the chamber by adjusting the magnitude of the clearance between the opposite and confronting surfaces of the stator and the rotor to a preselected target value during operation of the molecular pump.

Abstract: A bulk materials pump feeder having a housing and a rotatable drive rotor mounted in the housing for transferring material introduced into the housing through an inlet to an outlet for discharge of the material from the housing. The drive rotor has a hub and a plurality of drive discs extending away from the hub toward an inner wall of the housing. To reduce the tendency of material passing through the housing to wedge between the inner wall of the housing and the circumferential edges of the drive discs, the distance between the circumferential edges of the drive discs and the inner wall of the housing increases from the inlet of the housing to the outlet of the housing in the direction of rotation of the drive rotor.

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 vacuum pump is removably connected to the underside of a chamber for exhausting gas molecules from the chamber. The vacuum pump has a pump case having a flange extending circumferentially around a top portion thereof, a suction port and an exhaust port. Stator blades are fixedly mounted within the pump case, and a rotor is rotatably mounted in the pump case and has rotor blades alternately disposed with respect to the stator blades. A driving motor rotationally drives the rotor so that the rotating rotor blades coact with the stator blades to evacuate gas molecules from the chamber and pump the gas molecules from the suction port to the exhaust port. Bolt insertion holes are formed in the flange and each hole has a smaller diameter portion opening at a lower surface of the flange and a larger diameter portion opening at an upper surface of the flange which faces the underside of the chamber.

Abstract: A turbomolecular pump including a housing having a suction opening and a gas outlet opening, and a plurality of alternatingly arranged one behind another, stator and stator rings provided, respectively with support rings for supporting each a blade, with a support ring of a stator disc located adjacent to a high pressure region of the turbomolecular pump being connected with an adjacent housing part over a large surface or being formed with the adjacent housing part as one-piece part.

Abstract: A vacuum pump (1) includes a housing (2) in which a suction inlet opening (5) is defined. A vibration absorber (7) includes a suspension body (8) and an absorber jacket (9). The housing (2) of the vacuum pump (1) is connected directly to one end of the suspension body (8) in vacuum-tight connection and an opposite end of the suspension body carries a connecting port (14). By connecting the suspension body directly with the housing without mechanically releasable interconnection elements, the overall height of the pump and suspension body assembly is reduced.

Abstract: The present invention provides a vacuum pump which reduces a damaging torque produced when a rotor rotating at high-speed crashes into a screw stator or the like. The vacuum pump has a rigid ring disposed around the screw stator such that a shock load from the screw stator causes the rigid ring to rotate. When a brittle facture occurs in the rotor rotating at high-speed, for example, and a part of the rotor crashes into the screw stator, a rotating torque, i.e., a damaging torque causing the entire vacuum pump to rotate is likely to occur. However, this damaging torque is absorbed by the rotation of the rigid ring and eventually subsides.

Abstract: A propellantless hydrodynamic centrifugal thruster (122) comprising a hydrodynamic stator (102) with a hydrodynamic stator chamber (104) housing a centrifugal thrust generator (106) with a plurality of radial chambers (112A through L), and a propulsion fluid (114). The radial chambers (112A through L) are distributed in an annular array on one face of the centrifugal thrust generator (106). The centrifugal thrust generator (106) spins at the rotational speed (WR) and employs the mass of fluid (114) to generate unbalanced centrifugal forces (Fc). The vector sums of all the unbalanced centrifugal force (Fc) vector components generate a propellantless and unidirectional propulsion force (F).

Abstract: A vortex generating apparatus has the capability of attracting and removably adhering one or more solid objects. The apparatus comprises an impeller housed within a shell. The vortex attractor generates a vortical fluid flow generally in the form of a helical or spiral shaped flow. The fluid flow creates a low pressure region extending from the impeller end of the device. This low pressure region is contained by the walls of the fluid flow, thus directing the attractive forces toward a surface and minimizing effects of ambient fluid on the system. When the surface is part of a stationary object, wall, floor or ceiling, the vortex attractor may move toward and adhere to the surface. When the surface is part of a movable object, the vortex attractor may attract the object and maintain the attracted position.

Abstract: A rotor having a set of radial peripheral vanes for a high vacuum turbomolecular pump is manufactured by forging a metal workpiece to obtain a generally cylindrical body (1,11) with homogeneous mechanical properties and subsequent mechanical workings.

Abstract: The present invention relates generally to systems and methods for facilitating the movement of fluids, transferring mechanical power to fluid mediums, as well as deriving power from moving fluids. The present invention employs an impeller system in a variety of applications involving the displacement of fluids, including for example, any conventional pumps, fans, compressors, generators, circulators, blowers, generators, turbines, transmissions, various hydraulic and pneumatic systems, and the like.

Abstract: A thread-groove pump mechanism portion PB employs a turn-back structure including a rotor formed of a multiple cylinder having an inner cylindrical rotor and an outer cylindrical rotor and a stator formed of a multiple cylinder having an inner cylindrical stator and on outer cylindrical stator. Gaps g1 and g3 defined by the outer walls of the rotor and the stator walls, and a gap g2 defined by the inner cylinder wall of the rotor and the stator wall during the rest of the pump are formed such that they increase with the distance from the rotor shaft center and g1>g2 and g1>g3 are satisfied. Thus, even if displacement occurs by the centrifugal force and thermal expansion during the operation of pump, predetermined gaps can be provided therebetween.

Abstract: A vacuum pump has a casing having an interior space, an inlet port for introducing gas molecules into the interior space, and an outlet port for discharging the gas molecules from the interior space. A rotor shaft extends into the interior space of the casing for undergoing rotation about a rotational axis. A stator is connected to the casing and has stator blades extending into the interior space of the casing. A rotor is disposed between the casing and the rotor shaft. The rotor has a preselected number of rotor blades disposed at an uppermost stage thereof and alternately disposed between the stator blades for undergoing rotation with the rotor shaft to direct gas molecules toward the outlet port. A rotational member is disposed between the inlet port and the rotor for undergoing rotation with the rotor shaft about the rotational axis. The rotational member has a generally conical-shaped surface gradually decreasing toward the inlet port.

Abstract: The present invention provides a vacuum pump in which a damaging torque produced when a rotating rotor crashes into the inner wall of a pump case, is prevented to transfer to a vacuum chamber so as to protect the vacuum chamber. Bolt-holes of flange portions, through which the vacuum pump and the vacuum chamber and also the pump case and a base member disposed below the pump case are fastened, respectively, are formed so as to have larger diameters than the shank diameters of corresponding bolts by 20% or more. With this arrangement, when the entire vacuum turns moved by the damaging torque, the pump case slips relative to the vacuum chamber and the base member by the gaps between the pump case-base member fastening bolt-holes and the pump case-base member fastening bolts. As a result, the damaging torque is absorbed and is prevented to transfer to the vacuum chamber.

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 protective device is provided for protecting a turbo molecular pump having a rotor mounted for undergoing rotation, an intake port for sucking gas by rotation of the rotor, and an exhaust port for exhausting the gas sucked from the intake port. The protective device has a detecting device for detecting the occurrence of an abnormal phenomenon in the turbo molecular pump. An abnormal phenomenon inference device infers a type of the abnormal phenomenon detected by the detecting device. A value obtaining device infers a magnitude of damage given to the turbo molecular pump by the abnormal phenomenon inferred by the abnormal phenomenon inference device and obtains a value weighted based on the inferred magnitude of the damage. A value accumulation device accumulates the value obtained by the value obtaining device. A sum obtaining device obtains a sum of the values accumulated in the value accumulation device.

Abstract: The invention relates to a turbomolecular vacuum pump comprising rows of rotor blades (3) and rows of stator blades (4) that alternately engage with one another at varying angles of attack (&agr;). The aim of the invention is to improve the properties of such a pump. To this end, at least a part of the blades (1 or 2) of the rows of blades (3 or 4) that are mounted on the pressure side thickens towards the rim facing the pressure side.

Abstract: A turbomolecular pump (10) comprises a stator, a pump rotor, 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) determining 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 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: In a flange 61 provided at the suction port of a molecular pump, a hollow portion 72 is provided adjacently to a bolt hole 14. The hollow portion 72 is a through hole penetrating the flange 61. Thereby, a thin-walled portion 71 is formed between the bolt hole 14 and the hollow portion 72. If a shock in the direction of rotation of a rotor portion is provided to the molecular pump, for example, by the destruction of the rotor portion, the flange 61 slides in the direction of rotation of the rotor portion together with the molecular pump. Thereupon, a bolt fixing the flange 61 to a flange of a vacuum system hits the thin-walled portion 71, so that the thin-walled portion 71 is plastically deformed in the direction of arrow B. Thus, by the plastic deformation of the thin-walled portion 71, energy for rotating the molecular pump is consumed as energy for plastically deforming the thin-walled portion 71, so that the shock provided to the molecular pump is cushioned.

Abstract: A micromachine including at least one bladeless rotor, said rotor being adapted to impart energy to device energy to or derive energy from a fluid. A rotor for a micromachine comprising at least a pair of closely spaced co-axially aligned discs defining opposed planar surfaces, at least one disc having at least one aperture whereby a fluid passageway is defined between the aperture, the planar surfaces and the periphery of the rotor, the rotor being formed of a single crystal material.

Abstract: A disc turbine inlet collects working fluid, introduces it into the rotor housing at a defined location and imparted at a defined injection angle with respect to the tangential motion of the discs in rotary motion. An injection angle within the optimum range delineated by this invention enables the working fluid to entrain stationary or slowly rotating discs into motion. The inlet design combines smooth sectional transitions and arcuate directional changes to minimize frictional losses. The inlet has a nozzle section which locates precisely into a receiving aperture of the turbine rotor housing.

Abstract: A cascade type pump arrangement for a particle beam device has first and second turbomolecular pumps, wherein an outlet of the second turbomolecular pump is forepumped by an intermediate pressure region situated between a main pump port and an outlet of the first turbomolecular pump. The particle beam device has a particle beam source operated in ultra high vacuum and a specimen chamber operated at pressures from high vacuum at least up to 1 hPa.

Abstract: The invention provides a rotor for a turbo/drag vacuum pump, the rotor comprising an upstream rotor segment of the turbine type made of metal or alloy, and a downstream rotor segment of Holweck type made of composite material. The downstream segment of the rotor has a reinforcing structure made of long fibers that are distributed in a manner that varies as a function of the section under consideration: in the annular connection region connected to the upstream segment of the rotor, the fibers are inclined and/or spaced apart in order to conserve sufficient flexibility for the composite material to enable it to deform so as to track deformation of the metal of the upstream rotor segment while it is in operation; in contrast, the fibers are close together and form turns that touch in the downstream region of the skirt, thereby guaranteeing greater stiffness in order to withstand the mechanical stresses that occur during high-speed rotation of the rotor in operation.

Abstract: A compound vacuum pump comprising at least one turbo-molecular stage and downstream therefrom a multi-channel molecular drag stage, a first inlet through which fluid can pass through the turbo-molecular stage and the molecular drag stage towards a pump outlet, a second inlet through which fluid can enter the pump at a location between the turbo-molecular and the molecular drag stages to pass only through the molecular drag stage towards the pump outlet, in which one or more channels of the molecular drag stage are adapted to communicate directly with the second inlet whilst the remaining channel or channels communicate with the turbo-molecular stage.

Abstract: To provide a vacuum pump used for semiconductor manufacturing, which has improved reliability and safety and in which damages to a pump casing, peripheral apparatuses, or the like are prevented from occurring by preventing the occurrence of rotor breakage due to corrosion. A balancer is provided in the outer circumferential surface of the rotor so as to face the inside of the gas passageway. A balancer main body is supported against the outer circumferential surface of a rotor through a fragile portion that is weak with respect to corrosive gasses, the fragile portion of the balancer is damaged by corrosion before any corrosive gas influence appears in rotor blades or the rotor, and the balancer falls off, thus forcibly causing an unbalanced state to appear in the rotor. The balancer thus possesses a function for balancing the rotor and a corrosion detecting function.

Abstract: A seal is disposed between a rotating part and a stationary part. At least one of the parts is provided with projections which protrude into the seal gap. The seal gap (5) extends approximately radially so that both parts are provided with projections which extend in an axial direction, which are located concentrically in relation to the axis of rotation of the rotating parts and which engage with each other. Said projections are configured in the form of rows of blade-like elements. This effectively seals approximately radially extending seal gaps.

Abstract: A vacuum pump has an end portion and a flange extending from a periphery of the end portion. The flange portion has first and second opposed main surfaces, and first and second bolt insertion holes extending through the first and second main surfaces. An auxiliary ring is connected to the first main surface of the flange portion of the pump case. The auxiliary ring has first and second opposed main surfaces, and a third bolt insertion hole extending through the first and second main surfaces of the auxiliary ring. An auxiliary ring attaching bolt extends through the third bolt insertion hole for connecting the auxiliary ring to a chamber housing disposed opposite the end portion of the pump case. A pump case supporting bolt extends through the second bolt insertion hole of the pump case flange portion and is connected to the auxiliary ring, and a pump case fastening bolt extends through the first bolt insertion hole of the pump case flange portion and is connected to the auxiliary ring.

Abstract: A friction vacuum pump for use in a system for regulating the pressure in a vacuum chamber includes a multistage turbomolecular vacuum pump section (6) whose stages each consist of a row of stator vanes and rotor vanes (14 or 13). The pump regulates the pressure of heavy gases or of a gas mixture containing heavy gases. To this end, the friction vacuum pump (1) is equipped with a molecular pump section (11) located on the fore-vacuum side and a space (21, 22, 23), in which the pump action is interrupted. The space is provided in the transition area from the turbomolecular vacuum pump section (6) to the molecular pump section (11) or in the transition area from the molecular flow to viscous flow.

Abstract: An object of the disclosure is to provide a vacuum processing apparatus capable of minimizing the size of the whole apparatus by reducing a floor area occupied by a vacuum pump. An etching apparatus 20 for applying an etching process on an object to be processed in a vacuum includes a processing vessel 21 for applying the etching process on a semiconductor wafer W introduced into the vessel 21 and a vacuum pump 30 arranged below the processing vessel 21 so as to be coaxial with the processing vessel 21, for sucking exhaust gas in the processing vessel 21 to form the vacuum.

Abstract: A vacuum pump including a housing having a suction opening in its high-vacuum region, a gas outlet opening in its high pressure region, pump-active cooperating rotor and stator components arranged in the housing for pumping gases from the suction opening to the outlet opening, with an end of the pump-active components adjoining the high pressure region being connected with the gas outlet opening via intermediate chamber, a heating device provided in the intermediate chamber and connected with stator components, which are located in the high pressure region, by a connection having a high thermal conductibility, and thermal resistance elements for separating the heating device from the housing.

Abstract: Turbomolecular vacuum pump (1) with an inlet (3) and an outlet (4) and rotor and stator vanes (5 and 6), situated between the inlet and outlet, whereby the rotor vanes (6) have front sides (11) and rear sides (12) in relation to the direction of rotation thereof; according to the invention, the pumping properties of the pump may be improved, whereby at least a part of the rotor vanes (6) comprises a rear side (12), convex on the suction-side and concave on the delivery side, or that at least part of the rotor vanes (6) comprises a front side (11), which is concave on the suction side and convex on the delivery side.

Abstract: The invention relates to a friction vacuum pump (1) comprising at least one turbomolecular pump stage, with a molecular pump stage that is subsequently connected on the pressure side, and with a transition stage mounted between the turbomolecular pump stage and the molecular pump stage. In order to improve the transition from the turbomolecular zone to the molecular zone, the transition stage has a flow section that is continuously tapered in the tangential direction.

Abstract: A disc turbine rotor assembly comprised of spaced-apart discs includes means of spacing apart disc members of said rotor assembly, which allow for local variation and radial expansion under various local operating temperatures, without allowing axial deflection, deformation, or excessive warping of the disc material. Spacing means and positioning are provided which maintain desired gaps between planar disc surfaces, and may also establish tangential waves in the disc membranes in order to enhance boundary layer effects. Disc and spacer spokes combine to form a vane-axial type exhaust.

Abstract: The invention relates to a friction vacuum pump (1) comprising a fixed element (7) bearing rows of stator blades and a rotating element (6) bearing rows of rotor blades. The rows of stator blades and rotor blades are arranged concentrically with respect to the axis of rotation (4) of the rotating element (6) and engage with each other. In order to create 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. 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.

Abstract: A vacuum pump has a casing having an inlet port and an outlet port, a flange integral with the casing and having a peripheral inner surface defining the inlet port and an end surface for connection to a container to be evacuated, and exhaust means for drawing in a gas through the inlet port and discharging the gas through the outlet port. A coating of material having low heat conductivity is disposed on the end surface of the flange.