Abstract: According to one embodiment, a multiple motor and/or pump array module for a drilling tool comprises a plurality of motors and/or pumps extending axially along generally parallel axes wherein the pumps are positioned along the axes next to each other in a parallel manner in generally the same axial location.

Abstract: Compressor arrangement having an axial compressor and a radial compressor which are arranged axially one behind the other on a common driveshaft which can be coupled to a drive and which each have a compression fluid input and a compression fluid output. The axial compressor is provided with first control elements and the radial compressor is provided with second control elements. The first control elements and second control elements are controllable separately so that the axial compressor and the radial compressor are controllable separately.

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 method for providing a flow control system for an aircraft. A compressor is removed from an existing air cycle machine, along with compressor ducting that is connected to a primary stage outlet of the heat exchanger and a secondary stage inlet of the heat exchanger in the existing air cycle machine. A first connector duct is provided and connected to the primary stage outlet of the heat exchanger and the secondary stage inlet of the heat exchanger. The turbine is removed from the existing air cycle machine, and a second connector duct is provided and connected to the upstream turbine duct directly and the downstream turbine duct.

Abstract: A vacuum pump (100) comprises a pumping mechanism having an annular pumping chamber (112, 114, 116) extending about a longitudinal axis (107) and through which fluid is pumped by the pumping mechanism. A plenum (126) located remote from the pumping mechanism has an inlet (128) for receiving fluid to be pumped by the pumping mechanism and a plurality of outlets (132) arranged about the longitudinal axis (107) for supplying fluid to the annular chamber.

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 centrifugal pump mounted in an external housing. The pump has a split housing containing an impeller with outwardly extending vanes that is mounted on a drive shaft. The drive shaft at one end is mounted to a sealed bearing within the external housing and at the other end to a drive.

Abstract: In one embodiment, a turbomachine for imparting energy to a multiphase fluid is provided. The turbomachine comprises a casing having an inlet and an outlet; an axial stage part comprising at least one axial stage; a mixed-flow stage part comprising at least one mixed-flow stage fluidly connected to the axial stage part; and a centrifugal stage part comprising at least one centrifugal stage fluidly connected to the mixed-flow stage part. The axial stage is defined by an angle between an axial impeller outlet flow and an axis parallel to a rotational axis of the shaft having a value between 0° and 5°, the mixed-flow stage by an angle having a value between 5° and 80°, and the centrifugal stage by an angle having a value between 80° and 90°.

Abstract: A housing includes a major component. The major component has a planar section. The planar section has an aperture constituting an inlet. The major component has a generally cylindrical peripheral section. A tangential extension is provided. The aperture constitutes an outlet. The housing also includes a minor component. The minor component has a planar section. The planar section has an aperture. The aperture constitutes an outlet. A tangential extension is adapted to overlie the major component for creating a chamber. A rotatable assembly includes an annular plate. The annular plate has an aperture. Spaced impeller segments are provided. A propeller is also provided. The propeller has an axial bore. Propeller blades are provided. Openings are provided between the blades. The bore is adapted to receive a drive shaft of a motor. In this manner the propeller and the annular plate and the impeller segments are rotated.

Abstract: A method and system for controlling machining processes are provided. The system includes a computer system communicatively coupled to a database. The computer system is configured to receive data relating to manufactured part processes, identify at least one machining process used to manufacture a part and a parameter of the at least one machining process, receive survey data relating to the manufacturing process parameters used during the at least one machining process, and receive identification data for the manufactured part. The computer is further configured to receive data relating to a design of experiment (DOE), determine an low cycle fatigue (LCF) life distribution, identify process parameters that affect the LCF, and determine an allowable range for each identified process parameters for safe operation. The computer system is further configured to output the process window embodied in a specification associated with at least one of the part and the process.

Abstract: A turbo vacuum pump of the present invention includes a suction part for sucking gas in an axial direction; a discharge section in which rotating impellers and stationary impellers are alternately arranged; a rotating shaft for rotating the rotating impellers; and a turbine impeller part fixed to the suction side end face of the rotating shaft. The rotating impellers include one or more turbine impellers for discharging the sucked gas in the axial direction, and one or more centrifugal impellers, located downstream of the one or more turbine impellers, for further discharging the discharged gas by a centrifugal drag effect. The one or more centrifugal impellers are fixed to the rotating shaft passing therethrough. The one or more turbine impellers are included in the turbine impeller part.

Abstract: A fan apparatus includes first axial fans each arranged with a rotation axis thereof extending perpendicularly or substantially perpendicularly to a mounting surface provided in a case designed to contain an electronic device; and second axial fans each having a rotation axis coinciding with the rotation axis of a separate one of the first axial fans. The first axial fans are arranged to rotate in a first rotation direction to introduce, send, or discharge air into, inside, or out of the case, while the second axial fans are arranged to rotate in a second rotation direction opposite to the first rotation direction to cause a flow of air in the same direction in which the first axial fans cause a flow of air. Both of the first axial fans and the second axial fans either share a common single-piece housing or have separate housings joined together.

Abstract: An inducer assembly comprising at least two sets of rotating and non-rotating helical inducer vanes. As the fluid enters the inducer, the fluid moves up through a first set of rotating vanes, and gains rotational momentum. The fluid then enters a second set of non-rotating vanes that use the rotational momentum of the fluid to progress the fluid forward while removing the rotation and consequently decreasing the net positive suction head required. The inducer is positioned at the inlet of a cryogenic centrifugal pump. Embodiments of the cryogenic centrifugal pump use a vertical rotational axis and include a thrust equalizing mechanism device to balance hydraulic thrust.

Abstract: A drain pump that maintains pump performance and reduces noise and vibration accompanying water scooping of a rotary impeller includes a large-diameter blade divided into an inner blade and an outer blade. A radius of an impeller scooping up water is the sum of the lengths of the inner and outer blades in a radial direction. The large-diameter blade is divided at a position where the amount of generated air bubbles is large, and the inner and outer blades are alternately disposed. Accordingly, air bubbles are escaped to a downstream side in a rotational direction, so that the intensity of the collision between the blades and air bubbles is decreased reducing noise caused by the burst of air bubbles and vibration caused by a collision load of the flow of a gas-liquid mixture.

Abstract: A differentially pumped mass spectrometer system comprises a mass spectrometer having a plurality of pressure chambers; a vacuum pump attached thereto and comprising at least three pump inlets, a first pumping section, a second pumping section downstream from the first pumping section, and a third pumping section downstream from the second pumping section, an outlet from a first, relatively low, pressure chamber being connected to a first pump inlet through which fluid can enter the pump from the first chamber and pass through the first, second and third pumping sections towards a pump outlet, an outlet for a second, medium pressure chamber of the spectrometer being connected to a second pump inlet through which fluid can enter the pump and pass through, of said sections, only the second and third pumping sections towards the pump outlet, and an outlet for a third, highest pressure chamber of the spectrometer being connected to a third pump inlet through which fluid can enter the pump and pass through, of sai

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: A suction stage for a pump with a centrifugal wheel, the suction stage including a rotational impeller equipped with a hub and arranged upstream of the centrifugal wheel, the suction stage further including a diffuser arranged between the impeller and the centrifugal wheel, the diffuser including a plurality of blades. The hub has a downstream surface extending axially so as to converge toward the centrifugal wheel, and the blades of the diffuser have free ends, the blades protruding radially toward the downstream surface.

Abstract: A turbofan engine of the invention is provided with a fan first-stage moving blade for taking an air therein, and a spinner rotationally driving the fan first-stage moving blade, the spinner has a spiral blade extending spirally to an outer side in a radial direction, sucking the air from a front face of the spinner and supplying the air to the fan first-stage moving blade. Further, the fan first-stage moving blade and the spinner are integrally coupled, and the spiral blade and the fan first-stage moving blade are formed such that blade surfaces are smoothly connected.

Abstract: A power turbine is provided in the form of a set of plates that cooperate to form a housing, with a set of spaced apart disks mounted on a shaft within the housing. Some of the plates and disks cooperate to allow gas or steam to be injected to provide a driving force on the shaft, while others of the disks and plates cooperate to form one or more integral pumps. The pumps are used to pull cooling liquid or water into the housing, and to cool the driving disks. In this way, the steam that drives the disks is condensed while still in the housing, with a water level maintained on the driving disks. In operation, the steam directly acts on the disks toward the outer circumference of the disks, but more toward the center of the disk, the steam transfers its energy to the water, and the water transfers the energy to the disk.

Abstract: A compressor for an exhaust gas turbocharger includes an exhaust gas turbocharger housing having a gas intake port, which substantially radially encloses a gas inflow area. Disposed in the exhaust gas turbocharger housing is a compressor wheel, which can be driven by an exhaust gas turbine. The compressor wheel bounds the gas inflow area in the gas intake port in the direction of flow of a gas. The gas intake port includes indentations on a side of the inflow area. The flow noise in normal operation of the compressor and the acoustic effect in the case of pumping are reduced with the indentations.

Abstract: A centrifugal fan, which equally maintains air-blowing capacities of both inlets regardless of different suction resistances of both inlets due to a driving device, and an air conditioner having the centrifugal fan. The centrifugal fan includes a rotary plate; first blades disposed at the edge of one surface of the rotary plate; and second blades disposed at the edge of the other surface of the rotary plate, and having a larger outer diameter than the outer diameter of the first blades. Thus, although a large flow resistance is generated at one inlet of the centrifugal fan due to the driving device, air-blowing capacities of both inlets are maintained equally.

Abstract: A housing includes a major component. The major component has a planar section. The planar section has an aperture constituting an inlet. The major component has a generally cylindrical peripheral section. A tangential extension is provided. The aperture constitutes an outlet. The housing also includes a minor component. The minor component has a planar section. The planar section has an aperture. The aperture constitutes an outlet. A tangential extension is adapted to overlie the major component for creating a chamber. A rotatable assembly includes an annular plate. The annular plate has an aperture. Spaced impeller segments are provided. A propeller is also provided. The propeller has an axial bore. Propeller blades are provided. Openings are provided between the blades. The bore is adapted to receive a drive shaft of a motor. In this manner the propeller and the annular plate and the impeller segments are rotated.

Abstract: A drain pump is provided that reduces the operating noise when the head is low. The drain pump has a pump casing, and an impeller. The pump casing has a drain inlet for sucking in drain water at a lower end part and a drain outlet for discharging drain water at a side part. The impeller has a shaft part disposed extending in a vertical direction inside the pump casing, a main blade disposed on the outer circumferential side of the shaft part, an auxiliary blade disposed on the lower side of the main blade, and a disc shaped dish part disposed between the main blade and the auxiliary blade. The dish part has an annular partition part extending upward from the outer circumferential edge part of the main blade, which is disposed at a position lower than the upper end part of the partition part.

Abstract: A turbo vacuum pump of the present invention includes a suction part for sucking gas in an axial direction; a discharge section in which rotating impellers and stationary impellers are alternately arranged; a rotating shaft for rotating the rotating impellers; and a turbine impeller part fixed to the suction side end face of the rotating shaft. The rotating impellers include one or more turbine impellers for discharging the sucked gas in the axial direction, and one or more centrifugal impellers, located downstream of the one or more turbine impellers, for further discharging the discharged gas by a centrifugal drag effect. The one or more centrifugal impellers are fixed to the rotating shaft passing therethrough. The one or more turbine impellers are included in the turbine impeller part.

Abstract: An electric blower includes an electric motor, a first fan, a second fan, a first casing and a second casing. The electric motor includes a motor body and a rotation shaft extending from the motor body only on one axial side of the motor body. The first fan is located to the one axial side of the motor body and defines a first axis of rotation aligned with the rotation shaft. The second fan is located to the one axial side of the motor body and further than the first fan from the motor body in an axial direction. The second fan defines a second axis of rotation aligned with the rotation shaft. The first fan and the second fan are driven by a driving force generated by the electric motor. The first fan is disposed in the first casing. The second fan is disposed in the second casing.

Abstract: An indoor unit of an air conditioner capable of enhancing heat exchange efficiency and reducing noise/vibration is provided. The indoor unit includes a main chassis, a front panel, a cross-flow fan, a fan motor, a heat exchanger, and a discharge port. The main chassis has a backside fixed on a place to be installed. The front panel is formed on the front of the main chassis and has a spacer formed in an inside thereof. The cross-flow fan is disposed in the inside of the space and provided in plurals on the same shaft. The fan motor provides rotational power to the cross-flow fan. The heat exchanger is formed on the front of the cross-flow fan with respect to the flowing direction of air. The discharge port guides discharge of the air blown from the cross-flow fan.

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: 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 turbo vacuum pump of the present invention includes a suction part for sucking gas in an axial direction; a discharge section in which rotating impellers and stationary impellers are alternately arranged; a rotating shaft for rotating the rotating impellers; and a turbine impeller part fixed to the suction side end face of the rotating shaft. The rotating impellers include one or more turbine impellers for discharging the sucked gas in the axial direction, and one or more centrifugal impellers, located downstream of the one or more turbine impellers, for further discharging the discharged gas by a centrifugal drag effect. The one or more centrifugal impellers are fixed to the rotating shaft passing therethrough. The one or more turbine impellers are included in the turbine impeller part.

Abstract: An indoor unit for an air conditioner capable of performing cooling and heating, as well as ventilation functions as a single unit is provided. The indoor unit includes a main chassis, a ventilation port, a cross-flow fan, a side fan, and a ventilation duct. The main chassis is installed on a mounting portion and composing its exterior. The ventilation port formed to pass through the main chassis for inletting and exhausting air. The cross-flow fan is installed on one side of the main chassis to blow air in a direction perpendicular to its rotating shaft. The side fan is formed next to the cross-flow fan. The ventilation duct is connected to the ventilation port of the main chassis to ventilate the air forcibly blown by the side fan.

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 drain pump is provided that reduces the operating noise when the head is low. The drain pump has a pump casing, and an impeller. The pump casing has a drain inlet for sucking in drain water at a lower end part and a drain outlet for discharging drain water at a side part. The impeller has a shaft part extending in a vertical direction inside the pump casing, a main blade disposed on the outer circumferential side of the shaft part, an auxiliary blade disposed on the lower side of the main blade, and a disc shaped dish part disposed between the main blade and the auxiliary blade. The dish part has an annular partition part extending upward from the outer circumferential edge part of the main blade, which is disposed at a position lower than the upper end part of the partition part.

Abstract: A vacuum pump comprises a first pumping section 106, and, downstream therefrom, a second pumping section 108. The pump comprises a first pump inlet 120 through which fluid can enter the pump and pass through both the first and second pumping sections towards a pump outlet, and a second pump inlet 122 through which fluid can enter the pump and pass through only the second pumping section towards the outlet. The second pumping section 108 comprises at least one turbo-molecular pumping stage 109a, 109b and, downstream therefrom, an externally threaded rotor 109c.

Abstract: An impeller includes a hub, a plurality of first blades, and a plurality of second blades. The first blades are disposed around the hub. The second blades are disposed between the first blades. The lengths of the second blades are shorter than those of the first blades. The impeller can avoid the airflow reflux and have good airflow efficiency.

Abstract: The present invention is concerned with an axial-flow or mixed-flow inducer (3) which is disposed upstream of a main impeller (2) for improving the suction capability of a pump such as a turbopump. In the inducer (3), a blade angle (?bt) from a tip (T1) to a hub (H1) at a blade leading edge (31) is substantially the same as an inlet flow angle (?1?t) at a designed flow rate.

Abstract: A spigot arrangement for split impeller (inducer and exducer) includes a recess of the exducer and means for reducing exducer blade root stresses and localized contact stresses between inducer and exducer.

Abstract: The present invention relates to vacuum pumps and a method for creating and maintaining a high vacuum. A vacuum pump includes a regenerative section and a turbo-molecular section. A common first rotor carries forward-rotating elements of both the regenerative section and the turbo-molecular section. Additionally, a second rotor carries counter-rotating elements of the turbo-molecular section. A first drive rotates the first rotor in a forward rotational direction while a second drive rotates the second rotor in a counter-rotational direction. The drives may be controlled to drive the common first rotor on start-up, and to later drive the second rotor.

Abstract: A bypass channel for use in an inter-turbine transition duct of a gas turbine engine is connected to a suction port disposed upstream of a high-pressure turbine and an injection port disposed downstream of the high-pressure turbine. The flow through the bypass channel is motivated by the natural pressure difference across the high-pressure turbine. The flow out of the injection nozzle is used to energize the boundary layer flow downstream of the high-pressure turbine in order to allow for the use of a more aggressively expanded inter-turbine duct without boundary layer separation.

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.

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 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: 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 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: 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: Circular pump with a pump chamber (14), which is disposed above a liquid basin, accommodates a radial impeller (16) with a vertical axis and has an intake connecting piece (24), which is disposed coaxially with the impeller (16), is connected with the liquid basin and accommodates an inner part of the impeller, which is equipped with vanes (38) and protrudes axially, or a further impeller (40), which is constructed as an axial impeller (40) for aspirating the liquid in the interior region of the pump chamber (14), and with at least one venting channel (32), which leads form the inner region of the pump chamber (14) to the outside and extends along the side wall of the intake connecting piece (24) up to about the plane of the intake opening (36) of the intake connecting piece (24), characterized in that at least one venting channel (32), with its lateral opening (31) in the side wall of the intake connecting piece (24), opens essentially in the radial direction to the pump chamber (14).

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: 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.