Abstract: The invention relates to a vane for a vane pump, in particular a vane vacuum pump, having a crucible-shaped housing and provided with a rotor mounted eccentrically and rotatably in the housing, wherein the vane is displaceably mounted perpendicular to the axis of rotation in the rotor and the free ends thereof are in contact with the interior circumferential surface of the housing, wherein the vane has a closed surface, at least in the sections protruding beyond the rotor, in the direction of the interior circumferential surface, and the surface is formed by an exterior wall, which is provided with a coating, wherein the coating is provided with perforations in the area located inside the rotor.

Abstract: A vane compressor has a plurality of vanes that are radially translatable and have outer ends. The vanes create zones between each pair of adjacent vanes, each zone having a given area. The vane compressor also has an axis about which the vanes rotate and an outlet for expelling compressed fluid. A first zone immediately following a second zone, which is in register with the outlet, has the same area as the second zone.

Abstract: A vane air motor configured to prevent uneven wear of vanes is provided. The vane air motor has a cylindrical member having a rotor chamber (19) defined by a circular cylindrical inner peripheral surface (11), and a vaned rotor. A plurality of air discharge openings (50) are provided over a predetermined length range in the axial direction of the rotor chamber. Each pair of axially adjacent air discharge openings are spaced from each other and overlap each other as seen in the circumferential direction of the rotor chamber.

Abstract: A pump insert of a vane-type pump having no dedicated housing, the insert being inserted in a gear housing.

Abstract: An upper casing receives a rotor, which is rotated by a drive force of a motor. The upper casing includes a pump chamber, which receives the rotor, a planar surface portion, which is formed around an opening of the pump chamber, and a through hole. A lower casing includes a planar surface portion, which is formed around the opening of the pump chamber, and a through hole. The lower casing closes the opening of the pump chamber to form the pump chamber in cooperation with the upper casing. A resilient sheet is placed between the lower casing and a mount portion of the motor and includes a through hole. A screw is received through the through holes of the upper casing, the lower casing and the resilient sheet to securely connect the upper casing, the lower casing and the resilient sheet to the mount portion. A lower casing side surface of the resilient sheet includes a plurality of primary protrusions.

Abstract: A vane pump may include an oval fixed portion of which an outer circumference may be oval, a rotation ring that may be rotatably disposed outside of the oval fixed portion with a gap and in which blade slots may be formed in a predetermined depth along a circular interior circumference of the rotation ring at a predetermined interval from each other, blades of which one end thereof may be slidably inserted into the blade slots respectively and of which the other end slidably contacts an outer surface of the oval fixed portion, an elastic member coupled to the rotation ring and elastically pushing the blades towards the oval fixed portion, and a drive portion connected to the rotation ring and rotating the rotation ring such that oil may be sucked through an expanding space that may be formed between at least two of the blades and oil may be pumped through a shrinking space that may be formed between at least two of the blades.

Abstract: In a traditional hybrid air engine it is complicated to adjust valve timing to compensate for different engine operating modes. Provided is an air compression method and apparatus. The air compression method can be carried out in a single stage with a plurality of air tanks (61, 63) coupled to a compressor (51). The compressor (51) may be a cylinder Air is added to the compressor (51) at atmospheric pressure. Pressurized air is then added to the compressor (51) from a low pressure air tank (61). The compressor (51) compresses the air and transfers a portion of it to a high pressure air tank (63). The remaining portion of the compressed air is transferred to the low pressure air tank (61) for use in the next compression cycle A cam shaft (27) having a two stroke cam (93) and a four stroke cam (95) for each intake valve (59) and exhaust valve (55, 57) is provided to control valve timing during different operating modes.

Abstract: An impeller for a vane cell pump includes, but is not limited to vane receptacles for receiving an at least radially movable pump vane. A chamber wall is formed between two adjacent vane receptacles to form a conveying chamber. The chamber wall has an axially projecting web for delimiting a movement of a position ring with respect to the radial movement of the pump vane. The chamber wall includes, but is not limited to a first wall region for secure receiving of the respective pump vane in the vane receptacle. The chamber wall further includes, but is not limited to a second wall region for forming a web thickness d of the web for secure abutment of a sintering tool. In addition, the chamber wall has a third wall region for forming an enlarged conveying chamber volume. As a result, the impeller is easily manufactured and has an enlarged pump capacity for the same installation space.

Abstract: A plasma-vortex engine (20) provided. The engine (20) consists of a plasmatic fluid (22) circulating in a closed loop (44) encompassing a fluid heater (26), an expansion chamber (30), and a condenser (42). The expansion chamber (30) is fabricated of magnetic material, and encompasses a rotor (72), fabricated of non-magnetic material, to which T-form vanes (114), also fabricated of non-magnetic material, are coupled. A shaft (36) is coupled to the rotor (72). During operation, the plasmatic fluid (22) is heated to produce a plasma (86) within the expansion chamber (30). The plasma (86) is expanded and a vortex (100) generated therein to exert a plasmatic force (93) against the vanes (114). The rotor (72) and shaft (36) rotate in response to the plasmatic force (93). A plurality of magnets (115,119) are embedded in the vanes (114) and rotor (72) to provide attractive and repulsive forces (97,99,101) and better seal the vane (114) to the expansion chamber (30).

Abstract: An engine having a rotor including at least one slot and at least one combustion chamber used to form a cavity is provided. The engine also includes at least one vane rollably disposed in the slot, and a block for receiving the rotor, and having a first quadrant including an inlet port, a second quadrant, a third quadrant, and a fourth quadrant having an outlet port. The vane moves through the first quadrant, drawing air into the block and the cavity. The vane then moves through the second quadrant, compressing the air. The vane then moves through the third quadrant, combusting the air, and forcing the rotor to rotate. The vane then moves through the fourth quadrant, forcing the air out of the outlet port.

Abstract: Positive-displacement auxiliary pumping systems for use in pump apparatus of different configurations are disclosed. The positive-displacement auxiliary pumping systems are included in positive-displacement rotary pumps having a casing defining a pumping cavity, an inlet port connected to the pumping cavity, a discharge port connected to the pumping cavity, and a positive-displacement auxiliary pumping port connected to the pumping cavity. Pumping elements move within the pumping cavity of the casing and define a collapsing pocket that maintains fluid communication with the positive-displacement auxiliary pumping port after the collapsing pocket is no longer in fluid communication with the discharge port.

Abstract: A pump includes a housing and a shaft rotatable about an axis. The shaft has a shaft diameter and has a portion disposed within the housing. A plurality of retractable vanes is coupled to the shaft and each vane includes a first end that contacts the housing. A seal element is positioned to define a seal between the shaft and the housing. The seal element includes a first bushing, a second bushing, and a dry seal assembly including a wiper that defines a diameter that is smaller than the shaft diameter.

Abstract: A power steering pump includes, an intake flow channel defined by a first surface; a chamber into which fluid is received; and a plate disposed between the first surface and the chamber. An opening having opposed terminal ends extends through the plate. The intake flow channel is in fluid communication with the chamber through the plate opening and is configured to direct fluid flow through the plate opening into the chamber at a location intermediate and spaced from the terminal ends. The intake flow channel is defined by a bottom surface and a sloped surface extending from the bottom surface toward the plate. The flow channel has a transition zone through which the bottom surface and the sloped surface are joined. The transition zone is located at a position along the intake flow channel at which it and one of the plate opening terminal ends are approximately superposed.

Abstract: A rotary compressor includes a first compressing unit and a second compressing unit arranged one on top of another with a partition board therebetween. The partition board is provided with a vertical hole and a horizontal hole. After the front end of an injection copper tube to inject a refrigerant liquid is loose fit in the horizontal hole, an injection liner having an outer diameter larger than the inner diameter of the injection copper tube is inserted into the injection copper tube from the back end and is pressed up to the front end to increase the diameter of the front end of the injection copper tube such that the injection copper tube is tight fit in the horizontal hole.

Abstract: The present invention relates to a heat engine having a housing. A generally triangular shaped rotor can drive an offset crank as it eccentrically rotates within the housing. Two inlets with valves and two exhausts are provided. The volume between each face of the rotor and the housing defines three expansion chambers. Six power cycles are provided (one by each expansion chamber times two inlets) per revolution of the rotor. Each valve controls the length of time that high pressure gas is allowed to enter each expansion chamber. The valves are controlled by a processor and close when enough pressure is supplied so that the pressures inside and outside the expansion chamber are equal when the chamber is fully expanded just prior to exhaust. Gates can provide a mechanical advantage to the rotor by reducing the amount of pressure applied to the back side of the fulcrum.

Abstract: A power steering oil pump may include a pump housing, a rotor that is equipped with a plurality of vanes and coupled to the pump housing to rotate therein, a cam ring inserted between the rotor and the pump housing to form a pumping space between the cam ring and the rotor, a rotor shaft that passes through the rotor and is fitted therein to transmit rotational force to the rotor, and a bush that has at least a first oil groove on an inner circumference thereof and supports the rotor shaft to a pump cover coupled to the pump housing while covering a portion of the rotor shaft which passes through the rotor, wherein at least a second oil groove is formed on an end portion of the vanes contacting with an inner circumference of the cam ring.

Abstract: A fluid transfer engine employs a case with a cylindrical inner wall having an operating radius extending from a case axis. A main rotor is carried within the case and incorporates a lobe with a major radius equal to and concentric with the operating radius of the case, the main rotor having a minor radius defining a body. Two peripheral rotors are diametrically opposed with respect to the case axis and rotate within rotor chambers extending from the case. Each peripheral rotor has a radius equal to the minor radius and a center of rotation located at twice the minor radius from the case axis. Each of the peripheral rotors rotates in uniform circular motion with the main rotor in sealing contact with the body and incorporates a sculpted recess for receiving the lobe of the main rotor.

Abstract: A split discharge vane pump is disclosed having a pump body that includes an interior pumping chamber having a central axis and defining a continuous peripheral cam surface, the cam surface including four quadrantal cam segments, wherein diametrically opposed cam segments have identical cam profiles, and each cam segment defines an inlet arc, a discharge arc and two seal arcs. A rotor is mounted for axial rotation within the pumping chamber and a plurality of circumferentially spaced apart radially extending vanes are mounted for radial movement within the rotor, wherein the plurality of vanes define an equal number of circumferentially spaced apart buckets which extend between the rotor and the cam surface of the pumping chamber for carrying pressurized fluid.

Abstract: Disclosed herein is an oscillating vane type pump actuator. The pump actuator of the present invention provides a method of preventing fretting corrosion from being caused on joined surfaces of elements. A cylinder (3c) has a comparatively low radial strength, and each of side covers (1c) and (2c) has a high radial strength. A cylindrical portion (1c-c), (2c-c) is provided on each side cover. Thus, when high pressure of work oil distorts the cylinder into a shape in which the cross-section of the cylinder becomes an ellipse-like shape, the cylindrical portions of the side covers act such that they are distorted in the same shape as that of the cylinder. Further, a passage that always communicates with a low-pressure side working chamber is formed in the contact surfaces between a fixed vane that is fixed to the cylinder and the side covers.

Abstract: A vane pump includes a casing and a rotary unit rotatably held within the casing. The rotary unit includes a base portion with radially outwardly opened slits extending radially with respect to a rotational axis of the rotary unit and vanes slidably fitted in the respective slits. An annular chamber is formed around the base portion within the casing and divided into a plurality of pump chambers by the vanes. Each of the pump chambers has a volume cyclically expanded and contracted during rotation of the rotary unit to discharge the fluid drawn into each of the pump chambers. The casing includes an inlet port through which to draw the fluid into the annular chamber. The inlet port is arranged to face a portion of the annular chamber extending between a middle position and a terminating position of an expanding section in which each of the pump chambers expands.

Abstract: A rotary compressor having a housing and a rotor positioned within an internal cavity of the housing. The rotor being configured to rotate about a rotor axis of rotation eccentric to a housing longitudinal axis. A gate is also provided that is slidably mounted therewith the rotor and movable axially about and between a first position, in which a distal end of the gate is positioned at a first distance from the peripheral surface of the rotor, and a second position, in which the distal end of the gate is positioned at a second distance from the peripheral surface of the rotor. The distal end of the gate being constrained to be spaced proximate from the inner wall surface of the housing as the rotor rotates about the rotor axis of rotation.

Abstract: A pump assembly includes a housing having a chamber in communication with an inlet and an outlet. A rotating ring, variable displacement vane pump is received in the chamber. The pump, and particularly the rotating ring, is supported by a fluid bearing in the chamber. A control is provided for selectively altering fluid flow to the bearing in response to one of hydrodynamic bearing pressure, boost flow pressure, and the pump stroke.

Abstract: A motor, comprising: an internal motor chamber, and a rotor rotatable therein. The rotor is drivable by having a pressure medium applied to it and a braking element for braking the rotor. The braking element is axially arranged directly adjacent to the rotor, wherein the braking element and the rotor are axially moveable with respect to each other and form a spring-loaded friction pair, at least between a front end face of the rotor and the braking element.

Abstract: An exemplary revolving vane compressor includes a cylinder having a discharge port in and through the cylinder. A rotor housed within the cylinder is eccentrically mounted relative to the cylinder. A vane is mounted in a slot in the rotor. The vane is for sliding movement relative to the rotor. The vane is securely connected to the cylinder to force the cylinder to rotate with the rotor. A pressure shell surrounds the cylinder and the rotor. Each discharge port is for discharging fluid into an enclosed volume of the pressure shell. The cylinder is held within the enclosed volume.

Abstract: A compressor includes a compression mechanism for suctioning gas through a suction path to compress the gas and discharging the compressed gas and a check valve for preventing backward-flow of the gas in the suction path. The check valve includes an accommodation hole (its one end is opened toward the suction path and its another end is functioned as a reservoir), a valving element accommodated within the accommodation hole movably, a valve seat provided at the opened end of the accommodation hole for closing the suction path while the valving element is pressed thereonto and an urging component for urging the valving element toward the valve seat. A release groove is grooved on an inner surface of the accommodation hole. The reservoir is communicated with the suction path through the release groove. The compressor can reduce machining cost, component count and weight in respect to the check valve.

Abstract: A metal part in which a base material of silicon-aluminum alloy having 1 to 25% by mass of silicon as an anode is immersed in an electrolyte together with a cathode, and at least a portion of a surface of the base material is anodized and coated with an anodic oxide film. A current density provided to both the anode and the cathode is increased from an initial current density of 0 A/dm2 at a rate between 0.15 and 0.35 A/dm2 per minute, wherein once the current density reaches a prescribed current density of between 0.8 A/dm2 and 1.2 A/dm2, the current density provided to the anode and the cathode is maintained at the prescribed current density.

Abstract: A vane pump may include an oval fixed portion of which an outer circumference may be oval, a rotation ring that may be rotatably disposed outside of the oval fixed portion with a gap and in which blade slots may be formed in a predetermined depth along a circular interior circumference of the rotation ring at a predetermined interval from each other, blades of which one end thereof may be slidably inserted into the blade slots respectively and of which the other end slidably contacts an outer surface of the oval fixed portion, an elastic member coupled to the rotation ring and elastically pushing the blades towards the oval fixed portion, and a drive portion connected to the rotation ring and rotating the rotation ring such that oil may be sucked through an expanding space that may be formed between at least two of the blades and oil may be pumped through a shrinking space that may be formed between at least two of the blades.

Abstract: The invention relates to increasing the fluid capacity and the fluid discharge pressure of a rotary sliding vane fluid compressor without significantly increasing the fluid discharge temperature. According to the invention supplemental air under pressure is added to a compressor's rotating pocket to increase the fluid capacity and fluid pressure in the pocket.

Abstract: A vane-machine with cylinder stationary and rotating parts is intended for use as a driving or a working machine, utilizing compressible or non-compressible media as the working fluid. The vane-machine basic embodiment comprises: a cylinder stationary part (A), cylinder rotating parts (B), a rotor (C), covers (D), and vanes with grooves (F). The cylinder stationary part has a shroud (1) within which the rotor with the vanes rotates. In the shroud there are radial rectangular openings (5 and 6) letting the media in and out. The openings may be of other shapes as well. The inner ring (8) of roller or sliding bearings are rotationally driven by the vanes. The rotor is positioned eccentrically-relative to the shroud axes. At the rotor there are firmly fitted lateral plates (14) that rotate jointly with the rotor. The vane-machine working chamber is delimited with the shroud, the inner rings, the vanes and the plates.

Abstract: A gas compressor includes a cylinder block, a rear side block, a front side block, a cylinder chamber segmented by the above three blocks, a rotor provided in the cylinder chamber, vane slots formed on the rotor, vanes inserted into the vane slots, and a suction hole provided on at least one of the front and rear side blocks. Refrigerant is suctioned into the cylinder chamber from the suction hole. An opening edge of the suction hole is composed of an in-chamber opening edge that locates within the cylinder chamber and an in-block opening edge that faces to a sidewall of the cylinder block. The in-chamber opening edge locates on a side of an oval inner wall away from an outer circumference of the rotor. According to the gas compressor, leaning of the vanes is restrained, so that ground damage or attrition of the blocks, vibrations and noises are restrained.

Abstract: Disclosed herein is a vane pump apparatus. The disclosed vane pump apparatus comprises a housing having an outlet channel; a reservoir tank which stores working oil and which is coupled to the housing; and a vane pump installed inside the reservoir tank to discharge the compressed working oil to the outlet channel.

Abstract: A vane pump assembly including a cam ring having an elliptical inner bore defining a hydraulic pumping chamber, the pumping chamber having an interior camming surface. The cam ring defines ports for admitting fluid into the pumping chamber. A rotor, within the cam ring, defines a plurality of radial vane slots. A vane assembly is supported in each vane slot to define vane buckets. Each vane assembly has an end dynamic vane seal for reducing leakage between the buckets. Front and rear side plates, separated by an annular spacer, enclose the pumping chamber. The pump assembly may also include floating front and rear rotor seals for reducing radially inward leakage. Each rotor seal is disposed within a groove formed in the rotor, wherein discharge pressure urges the rotor seals axially outward from the pumping chamber to create an effective seal against the respective side plate.

Abstract: A vane pump includes a motor, a rotor rotated by the motor, a first casing having a pump chamber accommodating the rotor and a first flat part in a periphery of an opening of the pump chamber, a second casing having a second flat part joined to the first flat part to gas-tightly or liquid-tightly close the opening of the pump chamber, an elastic sheet disposed between the second casing and the motor, and a screw penetrating the first casing, the second casing and the elastic sheet. The screw is configured to fasten and join the first casing, the second casing and the elastic sheet to the motor.

Abstract: The invention can be used in rotary vane pumps, hydraulic motors, hydrostatic differential gears and transmissions with high efficiency and at a high pressure. The inventive rotary vane machine is provided, in each power variable length chamber (7), with means which are used for insulating the power cavity thereof (8) and comprise at least two movable elements (9), which are arranged in such a way that sliding insulation contacts are formed between the insulation surface of one of the movable elements and the insulation surface of one part of an adaptive unit, between the insulation surface of the other movable element and the insulation surface of the other part of the adaptive unit and between the insulation surfaces of the movable elements (9). At least in one of said contacts, the two insulation surfaces are embodied cylindrical, and, at least in one contact, they are spherical, and at least in one of the remaining contacts, the two insulation surfaces are flat or spherical.

Abstract: A rotary piston machine has a cylinder provided with two ends to form a stator with inlet and outlet apertures, and a piston having a rotor eccentrically mounted within the stator. A vane is connected to the rotor by a hinge and forms an expanding and contracting chamber as the piston rotates. The piston is provided with a sealing means sufficient to restrict movement of gaseous/fluid matter between chambers during operation. The sealing means includes a flexible seal member with a mating lip positioned adjacent to the vane hinge. Each revolution of the eccentrically mounted piston causes the seal member to contact an inner cylinder wall to prevent the escape of displaced gaseous/fluid matter past the vane hinge. The flexible seal member contacts the cylinder wall and bends to form a lip seal resistive to the direction of pressurization.

Abstract: A vane pump comprising a case, a rotor disposed in the case, the rotor having a bore, a plurality of vanes radially moveable with respect to the rotor extend from the rotor, a drive shaft engaged with the bore, a second shaft fixedly connected to the case and extending from the case to slidingly engage the bore, a land extending from each end of the rotor, each land cooperating with the case to seal a fluid flow, and each land further axially controlling a rotor position within the case by a sliding engagement, and the drive shaft retainable in a predetermined position with respect to the case.

Abstract: A pump, for example, a vane-cell pump or a roll-cell pump, especially a gear pump, includes a two-stroke pump contour which includes at least one rise zone, at least one large circular area, at least one fall zone and at least one small circular area. The pump includes a rotor with radially displaceable vanes or rolls arranged in radial slits inside the pump contour.

Abstract: A lubricant-tight vane rotary vacuum pump includes at least one pump stage (17, 18) having a safety valve (3) for controlling gas flow to the pump stage, a lubricant pump, a lubricant reservoir (30) at least partially surrounding the pump stage housing (10, 40), and a hydraulic conduit (31) connecting the lubricant pump outlet (22) with the safety valve (3), with a pressurized lubricant flow through the hydraulic conduit (31) opening the safety valve (3), and a channel (32) branching from the hydraulic conduit (31) for delivering a pressurized lubricant into the lubricant reservoir (30).

Abstract: A vane pump according to the present invention is characterized in that a position of a first suction port located in the forward rotation direction of a rotor is brought closer to a suction port than a position of a second suction port located in the backward rotation direction of the rotor with the suction port as reference by positioning a side plate in the state where the discharge port is brought close to a mounting portion.

Abstract: A pump insert of a vane-type pump having no dedicated housing, the insert being inserted in a gear housing.

Abstract: An improved pivoting vane pump or motor with vane timing that minimizes friction by eliminating contact between the pressurizing vane 52a and the pressure surface, big seal 64 and produces constant pressure and volume outputs at a given rotational speed.

Abstract: A vacuum pump for a motor vehicle engine which has a stator and a chamber, has a side wall, and the side wall has a transversal section with a predetermined shape. The rotor mounted in the chamber is capable of rotating around a rotation axis parallel to the side wall. The vane mounted on the rotor is free to slide in a direction at right angles with respect to the rotation axis of the rotor, and the vane has a predetermined length and two opposite end portions that substantially slide along the side wall of the chamber. At least one of the end portions of the vane has at least one part that has a bend radius substantially equal to that of a part of the side wall, when the one vane is at a reference operating position.

Abstract: A pump housing, in particular a vane cell pump housing, having a suction connection point, from which a suction channel emerges which opens with a suction-channel opening into a receiving chamber in the pump housing, and having a pressure connection point, from which a pressure channel emerges which opens at a pressure-channel opening into the receiving chamber. The invention is distinguished by the fact that the suction connection point, the pressure connection point, the suction-channel opening and/or the pressure-channel opening are/is arranged in such a way that a minimum level of a conveying fluid which is present in the receiving chamber is not undershot in different installation situations.

Abstract: A motor driven by pressure medium supplied from an external pressure source. The motor comprises a motor casing with a working chamber, a stator pail which forms an axial supply pipe for supply of pressure medium to the working chamber, a rotor part which is rotatably mounted on the stator part and eccentrically arranged in the working chamber, the rotor part and the stator being provided with inlet ports for supply of pressure medium to the working chamber, a hinge part mounted on the rotor part and provided with a pivotably mounted piston which divides the working chamber into a pressure chamber and a discharge chamber, and a constantly open discharge opening which is arranged in the wall of the motor easing from the discharge chamber through which the medium is discharged.

Abstract: A vane machine comprises an inner rotor (28) and an outer rotor (51). A plurality of radially extending vane elements (32) separates first vane chambers (89) from one another. The van elements (32), with a radially inner end region (34), are accommodated in the inner rotor (28) in a radially displaceable manner and, with a radially outer end region (36), are accommodated in the outer rotor (51) in a pivotable manner. It is proposed that the radially inner end regions (34) of the vane elements (32) be accommodated in the inner rotor (28) at a fixed angle and that the outer rotor (51) comprise individual shoes (38) which are separate for each vane element (32) and in which the vane elements (32) are accommodated in a pivotable manner.

Abstract: The present invention is a variable displacement pump having an inner rotor rotatable about a first axis and having at least two slots. The pump also has at least two vanes, each located in a distinct one of the at least two slots. The pump also has an outer rotor rotatable about a second axis, operably associated with the inner rotor, the outer rotor having two or more recesses, each configured to receive one of the vanes. The pump also includes an expandable chamber formed by the outer rotor and the inner rotor, an eccentric ring surrounding the outer rotor, and a housing. The eccentric ring is located within the housing for adjusting the relative relationship between the first axis and the second axis in order to vary the displacement of the pump.

Abstract: A pump, in particular a sliding-vane pump, a roller cell pump, or a gear pump includes a rotating assembly, with, amongst other things, a rotor with radially-sliding vanes, rollers or gears and a drive shaft is provided. The rotor or a gearwheel is connected to the drive shaft by a toothing on the drive shaft and on the rotor or gearwheel for rotational drive.

Abstract: The present invention provides a multistage vacuum pump comprising at least a low pressure first stage and at least a high pressure second stage. At least one of the stages has at least one suction inlet for admitting gas to be pumped, and at least one of the stages has at least one delivery outlet that is open to the outside for exhausting pumped gas. The first and second stages communicate with each other in order to pass gas from the first stage to the second stage. The first stage operates at a flow rate that is smaller than that of the second stage. For an oil-seal rotary vane positive-displacement pump, the oil is injected into the stage having the greater flow rate.

Abstract: A rotary pump includes a stator having a chamber delimited by a circumferential wall, a cylindrical rotor tangent to the circumferential wall of the chamber and suitable for being driven in rotation around an axis eccentric with respect to the chamber, and at least a vane diametrically traversing the rotor by delimiting in the rotor two half shells, mutually separated by the walls guiding the vane. The two half shells are hollow, and inside these hollow half shells are housed elastic leaf springs forming one-way valves with respect to four passageways formed in the half shells; the discharge of the air-oil mixture takes place, after a centrifugation and a partial recycling, through passageways, also in the case of a counter rotation of the pump. This configuration allows a bidirectional use of the same rotor.

Abstract: A vane pump of the intravane type for pumping hydraulic fluid, wherein each vane of the pump has two intravanes and that pressurized oil is provided to one or both intravane regions when the vane is in a rise region of the pump. The pump is operated such that the pressurized oil is provided to both undervane regions when the pump is running at low speed but the pressurized oil is provided to only one of the undervane regions when of the pump is running at high speed.