Abstract: A bulk materials pump feeder having a housing and a rotating drive rotor for transferring material from an inlet to an outlet of the housing. The drive rotor has a hub. Drive disks extend away from the hub toward a housing inner wall and have a compliant edge configured to deflect or compress when presented with pinched material rather than jamming.

Abstract: A heat dissipating module includes a rotational member, a stationary member and a driving member. The rotational member meshes with the driving member and has an uneven surface at a side thereof to space to the stationary member. The stationary member has plural flow passages and each flow passage has an air inlet at an end thereof and an air outlet at another end thereof. When the driving member actuates the rotational member to rotate with the fluid, the fluid enters the stationary member via the inlet and gathers at the outlet before being guided outward for concentrating the air and cooling the heat dissipated object.

Abstract: A turbo pump for evacuating a process chamber minimizes the amount time necessary to reduce the speed of the rotor in preparation for performing maintenance in the process chamber or the like. The turbo pump includes a housing communicating with the reaction chamber, a plurality of fixed stator rings spaced from one another along an inner peripheral surface of the housing, a shaft supported for rotation in the housing, a stator base surrounding the shaft and having an electric coil, a plurality of rotor blades each extending between an adjacent pair of the stator rings, and an electrode disposed at an outer peripheral surface of the housing. The electrode can receive an electric charge opposite to that applied to the rotor to forcibly stop the rotation of the rotor. Also, an electrical contact can be conductively connected to the rotor.

Abstract: A pump or turbine is disclosed which includes a housing provided with at least one chamber, a rotor, which is rotatably mounted on a shaft in the chamber, an inlet, which communicates with the chamber at least at the location of the shaft, and an outlet channel, which communicates with the chamber at least at the periphery of the rotor. The pump or turbine moreover comprises at least one bypass channel, a first end of which opens into the outlet channel of the pump and a second end of which forms an inlet. The bypass channel may be used for increasing the propelling force or for pumping slurries, for example.

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: A regenerative pumping mechanism comprises a rotor having a series of blades positioned in an annular array on one side of the rotor, and a stator having an annular channel within which the blades rotate. In order to control the axial clearance between the rotor and the stator, an axial magnetic bearing actively controls relative axial movement between the rotor and the stator. This can allow the pumping mechanism to provide controllable axial sealing between the rotor and the stator, as opposed to radial sealing.

Abstract: A vacuum pump is provided in which gas molecules in a vacuum chamber are sucked and exhausted by the rotational motion of a rotor rotatably supported in a pump case. At least one nickel alloy layer is disposed on a surface of at least one component defining a flow path in the vacuum pump for increasing a resistance of the component to corrosion due to a corrosive effect of a gas flowing through the flowpath. A nickel oxide is formed on a surface of the nickel alloy layer and has a higher emissivity than that of the nickel alloy layer for increasing a quantity of heat radiated from the surface of the component when the component is heated during operation of the vacuum pump.

Abstract: A turbo vacuum pump comprising a suction part 23A that sucks gas in an axial direction; a discharge part 50 that discharges the gas sucked by the suction part 23A, the discharge part 50 having a plurality of rotating impellers 70, 80 and a stationary impeller 71 arranged so as to be opposed to each of the plurality of rotating impellers 70, 80; and a rotating shaft 21 that rotates the plurality of rotating impellers 70, 80, wherein the plurality of rotating impellers 70, 80 include at least one stage of a first turbine impeller 70 for discharging the sucked gas in the axial direction, the first turbine impeller 70 being fixed to a suction-part-side end face 15 of the rotating shaft 21, and at least one stage of a second turbine impeller 80 fixed to the rotating shaft 21 that extends through the second turbine impeller 80, the second turbine impeller 80 being arranged downstream of the first turbine impeller 70.

Abstract: A fluidic propulsion system providing controlled vehicular thrust produced by non-uniform acceleration of liquid within annular tubular containers attached to a vehicle.

Abstract: The present invention is a centrifugal pump that pumps high-viscosity liquids, slurries, and solids-containing liquids. The pump has a housing, a chamber formed within the housing, a first discoidal member positioned in the chamber, a second discoidal member positioned in that chamber, connecting rods connecting a periphery of the first discoidal member to a periphery of the second discoidal member, and a drive for rotating the first discoidal member and the second discoidal member positioned in the chamber. The first discoidal member is either a recessed impeller or half-regular closed centrifugal impeller. The second discoidal member is a recessed impeller, a disc impeller, or a half-regular closed centrifugal impeller. The second discoidal member has a hole in the center.

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 rolling fluid machine especially with a liquid spraying at the output, comprising a chamber (1) where at least a part of its inner surface has a rotary shape and the chamber (1) is provided with at least one inlet (2) of fluid and at least one outlet (3) of fluid. In the chamber (1) there is a rolling rotor (4) installed in a manner enabling rolling and swinging. In the chamber (1) the space (5) bellow the rotor (4) and the space (6) above the rotor (4) is interconnected by at least one additional channel (7).

Abstract: A vacuum pump including a tempering component arrangeable between the suction side flange of the pump and the connection flange of a recipient and having a tempering element.

Abstract: A load-lock and dry vacuum pump assembly includes a load-lock having a load-lock housing, the load-lock housing includes a mating system having a flange-like cylinder and a cylinder concentrically located relative to said flange-like cylinder; a dry vacuum pump that includes a shaft, a rotor, a first concentric cylinder and a second concentric cylinder extending outwardly from the rotor, and is integrally connected with the mating system, the first and second dry vacuum pump concentric cylinders, the flange-like cylinder, and the cylinder concentrically located relative to said flange being axially arranged with respect to the shaft; and a molecular drag compression stage formed by flanges having helical structures selectively provided on the first and second concentric cylinders, the flange-like cylinder, and the cylinder concentrically located relative to the flange.

Abstract: A fan assembly for creating an air current includes a bladeless fan assembly including a nozzle and a device for creating an air flow through the nozzle. The nozzle includes an interior passage and a mouth receiving the air flow from the interior passage. A Coanda surface located adjacent the mouth and over which the mouth is arranged to direct the air flow. The fan provides an arrangement producing an air current and a flow of cooling air created without requiring a bladed fan, that is, the air flow is created by a bladeless fan.

Abstract: A bladeless fan assembly includes comprising a nozzle mounted on a base housing a device creating an air flow through the nozzle. The nozzle includes an interior passage receiving the air flow from the base and a mouth through which the air flow is emitted. The nozzle extends substantially orthogonally about an axis to define an opening through which air from outside the fan assembly is drawn by the air flow emitted from the mouth. The depth of the base in the direction of the axis may be no more than twice the depth of the nozzle. The assembly produces an air current without requiring a bladed fan, that is, the air flow is created by a bladeless fan.

Abstract: A bracket/spacer design in a bladeless turbine, compressor or pump comprising of a hub for axial mounting and one or more arms connected to the hub. This bracket/spacer configuration contributes in part or completely to form one or more fluid flow chambers along with coinciding geometry of the neighboring disk or disks facilitating the entrance or exit of fluid for the purpose of extracting or infusing energy into or from the fluid. Furthermore, this invention includes a precise description of non-constant angular and axial geometry of the bracket/spacer arm or arms.

Abstract: A support device for rotatably supporting a rotor (1) and including a support rotor (2; 2?) connectable with the rotor (1); a support stator (3; 3?) and a connection element (5; 5?) displaceably supported in a housing portion (4a, 4b) of the support device and connected with the support stator (3; 3?), with the connection element (5; 5?) and the housing portion (4a, 4b) having each a flat surface (11; 10), and with the flat surfaces (11; 10) being located opposite each other and extending parallel to each other.

Abstract: Disclosed is a turbo-molecular pump, which comprises a rotor including a first cylindrical body formed with a part of a plurality of rotating blades arranged in multistage, a second cylindrical body integrally connected to an outer peripheral region of a downstream end of the first cylindrical body and formed with the remaining rotating blades, and a stress-releasing protrusion extending from the downstream end of the first cylindrical body along a direction of a rotation axis of the rotor. The turbo-molecular pump of the present invention can reduce a stress in the downstream end of the first cylindrical body.

Abstract: A hybrid turbomolecular vacuum pump includes a housing having an inlet port and an exhaust port, one or more axial flow stages located within the housing, each of the axial flow stages including a stator and an impeller, each having inclined blades, at least one additional vacuum pumping stage which is not an axial flow stage, the additional vacuum pumping stage being located within the housing and including a stator and an impeller, and a motor to rotate the impellers such that gas is pumped from the inlet port to the exhaust port. The vacuum pump does not include a molecular drag stage having a rotating cylindrical drum or a rotating disk with a flat pumping surface. The additional vacuum pumping stage may be a modified molecular drag stage, wherein the impeller includes a disk having a roughened or grooved pumping surface, and/or a regenerative stage.

Abstract: A Holweck vacuum pump includes a pump rotor (16) having a rotating tube (24), a respective pump stator (12,14) comprising a helical thread groove (21,23) on the radial inside and outside of said rotor tube (24), and an inlet-side rotor blade disk (28) provided with a supporting ring (30) which supports said rotor tube (24). The blades (18) of said blade disk include rotor-side shoulders (40) which support the supporting ring (30).

Abstract: A friction vacuum pump (10) comprises a housing (12) defining a vaneless pump stator (30), a rotor drive and a rotor support which rotatably supports a pump rotor (16) provided with a vane (18). The housing (12) surrounds the overall axial length of the pump rotor (16), the rotor drive and the rotor support. Prior art housings are of multipart configuration and thus comprise seals between the housing portions. The seals are difficult to coat and may be or become locations where leaks occur. In contrast, the housing (12) is of one-piece configuration such that, in any case, the region of the housing (12) which is in contact with the vacuum gas is free of seals.

Abstract: The present invention relates to turbomolecular vacuum pumps and an arrangement for reducing or eliminating an accumulated static charge in the rotor caused by an interaction of the rotor with either electrically charged or neutral particles in the pumped media. Electrical charge exchange between the rotor and the electrically grounded stator is effected through a wire or other means of electrical contact, or through charge emission devices such as a field emission tip. In either case, electrostatic charges in the rotor are reduced or eliminated.

Abstract: A differentially pumped mass spectrometer system comprises a mass spectrometer having first and second pressure chambers through which, during use, ions are conveyed along a path. A pump assembly (10) for differentially evacuating the chambers (62, 66, 68) is attached to the mass spectrometer. The pump assembly comprises a housing (12) attached to the mass spectrometer and a cartridge (14) inserted into the housing. The cartridge has a plurality of inlets (16, 18, 20) each for receiving fluid from a respective pressure chamber (62, 68, 66) and a pumping mechanism (30, 32, 34) for differentially pumping fluid from the chambers. The cartridge is inserted into the housing such that the pumping mechanism (10) is inclined relative to the ion path (76), but with the cartridge protruding into the mass spectrometer to such an extent that at least one of the inlets (16, 18) at least partially protrudes into its respective chamber (62, 68) without crossing the ion path.

Abstract: Provided are a fixing structure for fixing a rotor to a rotor shaft, in which the contact state of the contact surfaces of the rotor shaft and the rotor is stabilized to thereby maintain the rotation balance of the rotor shaft and the rotor, making it possible to prevent oscillation, and a turbo molecular pump having such a fixing structure. On the outer peripheral portion of the upper surface of a fastening portion (253), there is concentrically formed a rotor shaft (213) side contact surface (257) to be brought into contact with a rotor (103). Further, in the inner periphery of the contact surface (257), there is formed a spot facing portion (259) whose upper surface is recessed from the contact surface (257).

Abstract: A waterproof/dustproof structure includes a stationary member defining a liquid reservoir, a movable member being separated by a gap region from the stationary member and moving without touching the stationary member, and a liquid of high viscosity contained in the liquid reservoir for sealing an entrance area to the gap region. With its high viscosity, the liquid can suppress vibration of the movable member when it stops moving.

Abstract: An integrated liquid cooling system for removing heat from a heat-generating component includes a base (10), a pump (20) mounted in the base and a heat-dissipating member (30) communicating with the pump and coupling with the base. The pump includes a casing (21) having a chamber (212). A rotor (22), a partition seat (23) and a stator (24) are in turn received in the chamber. A top cover (25) is attached on the casing. The casing includes a bottom plate (214) having a bottom surface. The bottom surface of the bottom plate contacts the heat-generating electronic component for absorbing heat generated by the electronic component.

Abstract: A flange of a molecular pump is connected to a vacuum vessel by first bolts that extend through elongate holes in the flange and are bolted to the vacuum vessel. One or more buffering members are attached to the flange by the first bolts that extend through first openings in the buffering members and by second bolts that extend through second openings in the buffering members and are bolted to the flange. In the event of malfunction of the molecular pump that generates an abnormally high torque, the buffering members plastically deform and absorb the shock energy caused by the abnormal torque thereby preventing damage to the vacuum vessel.

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 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: 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 in the form of a molecular drag disk and a stator that defines a tangential flow channel which opens onto a surface of the disk, the rotor having an axis of rotation, and a motor that rotates the rotor so that gas is pumped from the inlet port to the exhaust port. The channel has a cross-section in a plane that contains the axis of rotation which varies in dimension as a function of distance from the axis of rotation. The channel cross-section is selected to limit the tendency for backflow in viscous or partially viscous flow conditions.

Abstract: A molecular drag, turbomolecular, or hybrid turbo/drag pump (5) of the invention has an outlet stage with a cylindrical peripheral wall (17) and a radial outlet orifice (23) passing through the cylindrical peripheral wall (17). An annular coaxial closure member (24) bears against the cylindrical peripheral wall (17) around the radial outlet orifice. The annular coaxial closure member (24) includes a through slot and optionally also a total closure shutter (26). The annular coaxial closure member (24) is caused to turn about the axis of the cylinder by a motor (8) in order to place its through slot or its total closure shutter (26) in register with the radial outlet orifice (23), or partially in register with the radial outlet orifice (23) in order to adjust the opening of the valve and regulate the gas flow pumped by the pump (5). A pump is thus provided that includes an integrated regulator and/or closure valve.

Abstract: A bulk materials pump feeder having a housing and a rotating drive rotor for transferring material from an inlet to an outlet of the housing. The drive rotor has a hub. Drive disks extend away from the hub toward a housing inner wall. Three structural features of the feeder reduce the tendency of material to jam between the drive rotor and the housing or other stationary parts. First, the distance between the circumferential edges of the drive disks and the housing inner wall increases from the inlet to the outlet in the direction of rotation of the drive rotor. Second, a low-friction brush seal disposed on the periphery of the drive disks seals the area between the periphery of the drive disks and the inner wall. Finally, a materials scraper having a flexible tip is mounted in the housing and extends into the drive rotor between the drive disks.

Abstract: A gas compressor based on the use of a driven rotor having a compression ramp traveling at a local supersonic inlet velocity (based on the combination of inlet gas velocity and tangential speed of the ramp) which compresses inlet gas against a stationary sidewall. In using this method to compress inlet gas, the supersonic compressor efficiently achieves high compression ratios while utilizing a compact, stabilized gasdynamic flow path. Operated at supersonic speeds, the inlet stabilizes an oblique/normal shock system in the gasdyanamic flow path formed between the rim of the rotor, the strakes, and a stationary external housing. Part load efficiency is enhanced by the use of a pre-swirl compressor, and using a bypass stream to bleed a portion of the intermediate pressure gas after passing through the pre-swirl compressor back to the inlet of the pre-swirl compressor. Inlet guide vanes to the compression ramp enhance overall efficiency.

Abstract: A method for fabrication of a locomotive diesel engine turbocharger turbine stage so as to avoid harmonic vibration in the turbine blades when the engine is operated at pre-selected throttle settings. Upon determining throttle settings for the engine and modeling of the turbocharger therefor, at least one natural vibration frequency of the turbine blades and a turbine nozzle vane excitation frequency as a function of turbocharger rotation speed are determined. Then the data obtained is analyzed to ascertain whether at least one data coincidence, that is whether a rotation speed correlative of a throttle setting has a coincidence over a predetermined range of both a natural frequency and said turbine vane nozzle excitation. If not, the model is suitable for fabrication of the turbocharger; if so, the model is modified by changing blade stiffness and/or vane numbering until no data coincidences are present.

Abstract: A device (1), for evacuating a chamber to pressures in the high vacuum range includes a suction-side vacuum pump (2) and an atmospheric-pressure-side vacuum pump (3). The suction-side vacuum pump (2) is a mechanical kinetic vacuum pump with a rotor (11) and a stator (10). The stator (10) has a rotationally-symmetrical inner surface which matches the outer rotor geometry. The rotor (11) in the mechanical kinetic vacuum pump (2) is provided with a structure (13) carrying out the gas pumping. Said gas pumping structure comprises webs (14), the angle and width of which decrease from the suction side to the pressure side. The gas throughflow is improved. The outer diameter of the rotor (11) and the inner diameter of the stator (10) of the suctnion-side pump decrease from the suction side to the pressure side.

Abstract: A two staged fluid propulsion apparatus of the type which utilizes prior art pitched blades combined with solid boundary layer disks supported by a novel rotating tubular flow conduit perforated to allow fluid flow to from the interior of the tube to the exterior surface positioned to outlet into spaces between a plurality of solid disks mounted within a volute case housing containing a singular fluid outlet and in communication with a plurality of fluid inlet ports.

Abstract: A molecular drag compressor includes a rotor disk coupled to a drive shaft for rotation about an axis, a stator disposed about the rotor disk, the stator defining a tangential flow channel, an inlet to the tangential flow channel and an outlet from the tangential flow channel, and a stationary baffle disposed in the tangential flow channel adjacent to the outlet. The baffle and the rotor disk have a gap between them. A surface of the baffle facing the rotor disk has cavities configured to produce turbulent gas flow through the gap between the baffle and the rotor disk and to thereby reduce leakage.

Abstract: Turbo-machinery and methods are disclosed for a bladeless conical radial turbine wherein fluid is directed axially within the pump body to produce an axial output. The rotor comprises a plurality of spaced apart conical elements. A plurality of spiraling flow paths may be provided to receive fluid to which fluid has been imparted by acceleration of the fluid through the spaces between the conical elements using boundary layer adhesion techniques. The fluid is smoothly directed to any number of subsequent boundary layer pumping stages which are axially positioned with respect to each other.

Abstract: A molecular drag vacuum pump configured for pumping a gas stream from an inlet to an outlet, the pump including a high-speed spinning disk or rotor disposed within a housing. A passageway is formed inside the housing adjacent the disk, and gas comes in contact with surfaces of the spinning disk in successive stages, conformable wipers being disposed adjacent the spinning disk to direct the gas stream to the successive stages. The disk can be powered by an integrated motor, comprising permanent magnets associated with the disk and cooperating coils associated with the housing. The wipers can include parallel ridges on a contacting face to facilitate creation of a conformable fit with the rotor. Seal rings may be disposed against the disk between gas passageways to reduce leakage therebetween, and the pump may include regenerative pumping pockets to help prevent backflow. The housing may have a modular configuration to allow two or more pump modules to be connected and operate in series.

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: The object of the present invention is to provide: high-reliability and long-life CO2 refrigerant compressor-use bearings that uses bearing materials high in wear resistance and in baking resistance, and; such a compressor, air conditioner, refrigerator, and hot-water supply machine that each employ these bearings.

Abstract: A rotary disc pump for pumping fluid materials, comprises a housing having a front and a back wall forming a chamber with a generally coaxial inlet in the front wall and a generally tangential outlet, an impeller is mounted co-axially within the chamber and comprises a shaft mounted in the back wall of said housing and having an outer end extending from the housing and an inner end within the chamber, at least a first circular which is disc mounted on the inner end of the shaft, and at least a second disc which is mounted in axially spaced relation to the first disc and has an opening in the center thereof, arid a conical member which extends co-axially of the shaft from the first disc toward the second disc.

Abstract: In a turbo-molecular pump with a high vacuum-side induction area and of a rotational symmetrical arrangement, comprising a compressor turbine including a rotor and a stator tube having axially alternately tightly arranged rotor blade rings and stator vane rings with oppositely oriented blade and vane surfaces, a pre-vacuum chamber with a gas guide structure for the connection of a pre-pumping system, a drive module and a bearing unit, the turbo-molecular pump has a center area with a central coaxial open space extending from an ambient end to the high vacuum-side induction area and the open space is closed at its end adjacent the ambient end thereof by a flange in a vacuum-tight manner or is connected to a vacuum recipient, and the high-vacuum end of this space is separated from a pre-vacuum space.

Abstract: A molecular pump has a casing having a gas inlet port and a gas discharge port, a stator disposed within the casing, a shaft disposed in the casing concentrically with the stator, a bearing rotatably supporting the shaft for undergoing rotation relative to the stator in a preselected direction of rotation, a rotor mounted on the shaft for rotation therewith in the preselected direction of rotation, and a motor for rotationally driving the shaft. A flange is connected to the casing at the gas inlet port.

Abstract: A gas friction pump, comprising stationary pump-active components (14) and rotatable pump-active components (15) secured on a rotatable rotor shaft (4), wherein the rotor shaft is supported with a bearing (5) at the high-vacuum-side end and a bearing arrangement at a fore-vacuum side end, characterized in that the high-vacuum side bearing is formed as a conventional bearing, and the fore-vacuum bearing arrangement contains at least one gas bearing. In an advantageous embodiment, the gas bearing is formed as a module and can be brought in engagement with a cylindrical portion of the housing and secured therein.

Abstract: A bulk materials pump feeder having a housing and a rotating drive rotor for transferring material from an inlet to an outlet of the housing. The drive rotor has a hub. Drive disks extend away from the hub toward a housing inner wall. Three structural features of the feeder reduce the tendency of material to jam between the drive rotor and the housing or other stationary parts. First, the distance between the circumferential edges of the drive disks and the housing inner wall increases from the inlet to the outlet in the direction of rotation of the drive rotor. Second, a low-friction brush seal disposed on the periphery of the drive disks seals the area between the periphery of the drive disks and the inner wall. Finally, a materials scraper having a flexible tip is mounted in the housing and extends into the drive rotor between the drive disks.

Abstract: A pump which is bladeless, and uses a substantially cylindrical outer cylinder to rotate inside a ridged inner chamber.

Abstract: An ultra-high speed vacuum pump evacuation system includes a first stage ultra-high speed turbofan and a second stage conventional turbomolecular pump. The turbofan is either connected in series to a chamber to be evacuated, or is optionally disposed entirely within the chamber. The turbofan employs large diameter rotor blades operating at high linear blade velocity to impart an ultra-high pumping speed to a fluid. The second stage turbomolecular pump is fluidly connected downstream from the first stage turbofan. In operation, the first stage turbofan operates in a pre-existing vacuum, with the fluid asserting only small axial forces upon the rotor blades. The turbofan imparts a velocity to fluid particles towards an outlet at a high volume rate, but moderate compression ratio. The second stage conventional turbomolecular pump then compresses the fluid to pressures for evacuation by a roughing pump.

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.