Abstract: Embodiments of the present invention relate generally to certain types of reciprocating positive-displacement pumps (which may be referred to hereinafter as “pods,” “pump pods,” or “pod pumps”) used to pump fluids, such as a biological fluid (e.g., blood or peritoneal fluid), a therapeutic fluid (e.g., a medication solution), or a surfactant fluid. The pumps may be configured specifically to impart low shear forces and low turbulence on the fluid as the fluid is pumped from an inlet to an outlet. Such pumps may be particularly useful in pumping fluids that may be damaged by such shear forces (e.g., blood, and particularly heated blood, which is prone to hemolysis) or turbulence (e.g., surfectants or other fluids that may foam or otherwise be damaged or become unstable in the presence of turbulence).

Abstract: A method of operating a reciprocating compressor for a vapour compression system is disclosed. The reciprocating compressor comprises at least two cylinders and at least two unloaders, each unloader can be operated in an idle mode or in an active mode and therefore the reciprocating compressor can run in more than two capacity states. The capacity states alternates periodically between states in such a way that a substantially continuous range of effective capacities can be obtained while the individual cylinders are evenly loaded.

Abstract: A method of pressurizing a downstream compressor system operatively connected to an upstream compressor system by using a bleeding line connected at a first end to the downstream compressor system and at a second end at least to one bleeding region or tie-out region of the upstream compressor system.

Abstract: A compressor of the present invention comprises a crankshaft, a first compression part, and a second compression part for further compressing a gas discharged from the first compression part. The first compression part comprises a first reciprocating motion conversion part, a first pressing part, and a first cylinder body comprising a plurality of cylinder components, while the second compression part comprises a second reciprocating motion conversion part, a second pressing part, and a second cylinder body comprising a plurality of cylinder components. The number of the cylinder components of the second cylinder body is smaller than that of the cylinder components of the first cylinder body.

Abstract: The pump is provided with a plurality of pumping chambers and electrically activatable valves. An elastic membrane is arranged in each pumping chamber and divides the same into a first and a second chamber section. Each valve is connected to the second chamber section of a pumping chamber. When a pressure drop is applied over the valve and the valve is activated (i.e. opened), the pressure in the second chamber section changes, which causes the membrane to move, which in turn leads to a change of the volumes of both chamber sections. This e.g. allows to pump well-defined amounts of fluid from the chamber sections to a drug dispensing device.

Abstract: An aircraft engine fuel system is provided and includes a pump, including an inlet and an outlet, from which pressurized output is produced, a valve disposed downstream from the pump outlet to receive and to direct the pump output flow toward the engine and to provide a leak tight seal when the pump is not operating, a sensor configured to issue a signal reflective of a state of the valve at first and second conditions and a controller, operably coupled to the pump and the sensor, which is receptive of the signal and which modifies performance models of the pump and engine to control pump speed to modify pump flow accordingly.

Abstract: A compressor includes a housing; a compressor liner positioned within the housing and at least partially defining a first cylinder with an inlet and an outlet; a piston positioned within the first cylinder and configured to compress air flowing into the first cylinder through the inlet; a cylinder head at least partially defining the first cylinder; and a sealing assembly for sealing an interface between the compressor liner and the cylinder head. The sealing assembly includes a ring seal at an interface between the cylinder head and the compressor liner; a vent port on an opposite side of the ring seal from the first cylinder; and a vent tube extending between the vent port and the inlet such that air leaking through the ring seal from the first cylinder flows through the vent port, through the vent tube, and into the inlet.

Abstract: The present application discloses a natural gas compressor, a natural gas compressor assembly, a system for compressing natural gas, and a method of compressing natural gas. In certain embodiments, the natural gas compressor comprises a housing, a plurality of cylinder piston assemblies disposed within the housing, and a drive system for moving the pistons of the cylinder piston assemblies to compress natural gas within the cylinders of the assemblies. Each cylinder piston assembly comprises a piston for compressing natural gas within a cylinder of the assembly. The plurality of cylinder piston assemblies are fluidly connected in sequence such that each assembly forms a compression stage of the compressor.

Abstract: A fluid compressor 10 comprising a stator 22, having a bore shaped first chamber 26 and an annular second chamber 30, and a piston 18 comprising a central piston rod 36 having a first piston head 44 and a concentrically arranged cylindrical piston sleeve 38 having a second piston head 48. The stator 22 and piston 18 together define a first compression chamber 12, a second compression chamber 14 provided concentrically around the first chamber 12, and a third compression chamber 16 provided concentrically around the first chamber 12 and linearly with the second chamber 14. The compression chambers 12, 14, 16 are interconnected via intercooling conduits 72, 74. A hydraulic actuator 20 is coupled to the piston 18 by a hydraulic ram 82. During left to right movement of the piston 18 fluid enters the third chamber 16 and fluid is compressed in the second chamber 14.

Abstract: Apparatus (1) for providing a supply of natural gas fuel comprising a compressor (2) having an inlet (3) for a stream of natural gas (4), wherein the inlet (3) may be placed in fluid communication with an LNG storage tank (5) in order to provide a supply of boil-off gas (6) from out of the LNG storage tank (5), and an outlet (7) which may be placed in fluid communication with a natural gas supply pipe (8), characterised in that the compressor (2) comprises a first and subsequently a second compression stage (9, 10), wherein the first and the second compression stage (9, 10) take the form of labyrinth-sealed piston-compressors (11, 12) or piston-ring-sealed piston-compressors (15), and wherein the first compression stage (9) features a larger piston diameter than the second compression stage (10), and that the compressor (2) comprises at least a third subsequent compression stage (13, 14), which takes the form of a piston-ring-sealed piston-compressor (11, 12) or a labyrinth-sealed piston-compressor (15).

Abstract: A differentially pumped vacuum system includes first, second and third chambers, and a pumping arrangement for evacuating the chambers. The pumping arrangement includes a compound pump having a first inlet connected to an outlet from the first chamber, a second inlet connected to an outlet from the second chamber, a first pumping section and a second pumping section downstream from the first pumping section, the sections being arranged such that fluid entering the compound pump from the first inlet passes through the first and second pumping sections and fluid entering the compound pump from the second inlet passes through, of said sections, only the second section. The pumping arrangement further includes a booster pump connected to an outlet from the third chamber, and a backing pump connected to the exhaust from the booster pump. Fluid exhaust from the compound pump can be conveyed to either the booster pump or the backing pump as required.

Abstract: A multistage reciprocating air compressor compresses air to an elevated pressure level discharge with an intermediate pressure level discharge for use in blow moulding of PET bottles and similar products. The air compressor has a first, second and third reciprocating piston stages, including respective inlet unloading means, with first, second and third actuating means operable in response to respective sensed discharge pressure levels from the discharges to actuate inlet unloading means. The elevated pressure level discharge being from the third stage and the intermediate pressure level discharge being from an interstage region between at least one of the first and second stages or the second and third stages.

Abstract: A multistage compressor installation in which compression stages utilizing centrifugal compressors are independently driven by drivers that can be electric motors configured to be controlled by a speed controller. Intercoolers are located between stages to remove the heat of compression and the stages are connected such that outlets are located opposite to inlets of the compressors and conduits connecting the intercoolers to the stages are in an in-line relationship to inhibit the formation of pressure drops between stages. The conduits connecting the stages incorporate tapered transition sections configured such that flow velocity gradually decreases towards the intercooler and gradually increases from the intercooler to the next succeeding compression stage to further inhibit pressure drops.

Abstract: A method of operating a multistage gas compressor system including providing a plurality of compressor stages connected in series, receiving a gas flow having contaminants within a gas passage, and supplying solvent to the gas passage at or upstream of a compressor in a compressor stage of the plurality of compressor stages to entrap or dissolve the contaminants in the gas flow. The method includes resisting disabling fouling of the compressor in the compressor stage from any contaminants entrapped or dissolved in the solvent, for example, by controlling a discharge temperature of the compressor, and/or using a type of compressor that is not susceptible to being disabled by fouling in at least the first stage. The discharge temperature can be controlled by providing the compressor with a pressure ratio selected to provide a desired discharge temperature.

Abstract: An air pump is provided that is configured to move and compress air into an air storage vessel at high pressure. The air pump is operable to move large volumes of air against low resistance for rapid filling of an air storage vessel.

Abstract: In one aspect, a system for delivery of a medical fluid to a patient includes a pump system including a plurality of at least three chambers. Each of the plurality of chambers includes an inlet through which fluid is drawn into the chamber and an outlet from which fluid is expelled from the chamber. The pump system further includes a common outlet channel in fluid communication with the outlet of each of the plurality of chambers and a plurality of at least three pistons. Each of the pistons is slidably disposed within a respective one of the plurality of chambers. The system further includes a drive system including a cam shaft including a plurality of at least three cam lobes. Each of the plurality of cam lobes has a profile. The drive system further includes a plurality of at least three cam lobe followers.

Abstract: A differentially pumped vacuum system includes first, second and third chambers, and a pumping arrangement for evacuating the chambers. The pumping arrangement includes a compound pump having a first inlet connected to an outlet from the first chamber, a second inlet connected to an outlet from the second chamber, a first pumping section and a second pumping section downstream from the first pumping section, the sections being arranged such that fluid entering the compound pump from the first inlet passes through the first and second pumping sections and fluid entering the compound pump from the second inlet passes through, of said sections, only the second section. The pumping arrangement further includes a booster pump having an inlet connected to an outlet from the third chamber, and a backing pump having an inlet connected to the exhaust from the booster pump. Fluid exhaust from the compound pump can be conveyed to either a second booster pump inlet or the backing pump inlet as required.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A multiple-stage gas compressor is disclosed by this application. The compressor has a plurality of pistons, including at least one wobble piston assembly and at least one cylinder piston assembly for compressing pressurized gas from the at least one wobble piston. The wobble piston assembly includes a wobble piston head fixed to a wobble piston connecting rod. The cylinder piston assembly includes a cylindrical piston head pivotally connected to a cylindrical piston connecting rod.

Abstract: A reciprocating compressor includes: a low-pressure stage compression part for compressing low-pressure working gas supplied from a supply source; two high-pressure stage compression parts for compressing the working gas compressed by the low-pressure stage compression part at two stages; and a crank mechanism for driving the low-pressure stage compression part and the high-pressure stage compression parts. The two high-pressure stage compression parts each have a plunger and a cylinder and are arranged on both sides of the crank mechanism in such a way as to extend coaxially opposite to each other. The low-pressure stage compression part has a piston and a cylinder and is located in the middle of the two high-pressure stage compression parts. The crank mechanism, the low-pressure stage compression part, and the two high-pressure stage compression parts are substantially located in the same plane.

Abstract: A fluid compressor 10 comprising a stator 22, having a bore shaped first chamber 26 and an annular second chamber 30, and a piston 18 comprising a central piston rod 36 having a first piston head 44 and a concentrically arranged cylindrical piston sleeve 38 having a second piston head 48. The stator 22 and piston 18 together define a first compression chamber 12, a second compression chamber 14 provided concentrically around the first chamber 12, and a third compression chamber 16 provided concentrically around the first chamber 12 and linearly with the second chamber 14. The compression chambers 12, 14, 16 are interconnected via intercooling conduits 72, 74. A hydraulic actuator 20 is coupled to the piston 18 by a hydraulic ram 82. During left to right movement of the piston 18 fluid enters the third chamber 16 and fluid is compressed in the second chamber 14.

Abstract: A centrifugal pump has impellers for pumping low flow, high viscous materials. The impellers have high exit angles greater than 30 degrees and preferably greater than 50 degrees. The impellers and diffusers have specific geometry that varies with viscosity. The pump has zones of impellers and diffusers with the exit angles and geometry in the zones differing from the other zones. The exit angles decrease and geometry varies in a downstream direction to account for a lower viscosity occurring due to heat being generated in the pump. One design employs small diameter impellers and high rotational speeds.

Abstract: A multi-stage compressor is disclosed, which comprises: two motion converters driven by one driving shaft and converting a rotary motion to a straight-line reciprocating motion; first and second pistons (62) connected to one of the motion converters in opposite directions and moving reciprocatively in a straight line; and third and fourth pistons (72) connected to the other one of the motion converters in opposite directions, arranged at a predetermined angle with respect to the first and second pistons (62), and moving reciprocatively in a straight line, and which is characterized in that at least two of the four pistons operate for first-stage compression and at least one of the others operate for second-stage compression.

Abstract: A pumping apparatus (1) adapted for delivering fluid against pressure. The pumping apparatus has a plurality of metering devices (3,5) adapted for metering a plurality of different fluids, and has a booster device (7) adapted for increasing the pressure of the fluids metered by the plurality of metering devices (3,5) to said high pressure, and has a damping device (9) adapted for compensating fluctuations of the fluids metered by the plurality of metering devices (3,5). Each device (3,5,7,9) has an inlet (41) and an outlet (43). The outlets of the metering devices are coupled to the inlet (41) of the booster device (7), and the outlet of the booster device (7) is coupled to the inlet of the damping device (9).

Abstract: A multi-stage vacuum pump comprises a first piston in a first cylinder defining a first stage pumping chamber and a second piston in a second cylinder defining a second stage pumping chamber. The pump has a spool valve between the first and second cylinders for controlling flow from the first stage pumping chamber to the second stage pumping chamber. Either the first cylinder and the first piston or the second cylinder and the second piston being stepped so as to define a third stage pumping chamber. The spool valve is arranged to control the flow from the second stage pumping chamber to the third stage pumping chamber.

Abstract: An oxygen-compression apparatus has a driving device, multiple rotating wheels, multiple driving rings, multiple rocking cylinders and multiple connecting hoses. The driving device has a driving shaft with a central axis. The rotating wheels are eccentrically attached on and rotated with the driving shaft and are located respectively at different angles relative to the central axis of the driving shaft. The driving rings are rotatably mounted respectively around the rotating wheels. The rocking cylinders are connected respectively to the driving rings and each has a housing and a piston rod. The piston rod has a first end extending into the inner space of the housing to form a compression chamber in the inner space and a second end pivotally connected to a corresponding one of the driving rings. The connecting hoses are connected between the compression chambers of adjacent rocking cylinders.

Abstract: A centrifugal pump has impellers for pumping low flow, high viscous materials. The impellers have high exit angles greater than 30 degrees and preferably greater than 50 degrees. The impellers and diffusers have specific geometry that varies with viscosity. The pump has zones of impellers and diffusers with the exit angles and geometry in the zones differing from the other zones. The exit angles decrease and geometry varies in a downstream direction to account for a lower viscosity occurring due to heat being generated in the pump. One design employs small diameter impellers and high rotational speeds.

Abstract: A portable high pressure compressor, which high pressure and small size is achieved by mounting 4 diaphragm type cylinder-piston assemblies on a common drive shaft. Each cylinder-piston assembly represents a stage of a 4-stage cycle, where the pressure between the stages is continuously increased.

Abstract: A pump system for multi-phase fluids that includes a drive-shaft (11), mechanical differential units (12, 22, 23, 23′, D1 . . . Dn) and pumps (14, 14′, 25, 25′, 25″, 25′″, B1 . . . Bn) where the differential units allow for the changing of pump rotation speeds between pumps(14, 14′, 25, 25′, 25″, 25′″, B1 . . . Bn) so as to adjust the compressibility of fluids in order to reduce or eliminate circulatory flow. There is also a description of the method of operating the system according to the invention.

Abstract: A multi-stage compressor comprises a gas compressor, a centrifugal blower having an input connected with a gas source and an output connected with the gas compressor and providing a flow of compressed gas as a first stage of compression to the gas compressor, and a power source mechanically connected with and driving both the centrifugal blower and gas compressor to provide multi-stage compression of said gas.

Abstract: There is disclosed a high-pressure compressor comprising a compression mechanism for reciprocating/driving a piston with respect to a conventional cylinder by rotation of a motor and compressing an operating fluid sucked by this driving to generate the high-pressure operating fluid according to improvements in a piston shape, positions of a cylinder operation surface and the piston, specifics shapes of the cylinder and piston, and connecting constitution of the piston to a connecting rod, which solves problems such as occurrence of wear on a cylinder inner surface by displacement of the piston, size enlargement by an increase of a removal capacity, difficulty in processing the piston and connecting rod, and a large top clearance.

Abstract: There is disclosed a high-pressure compressor comprising a compression mechanism for reciprocating/driving a piston with respect to a conventional cylinder by rotation of a motor and compressing an operating fluid sucked by this driving to generate the high-pressure operating fluid according to improvements in a piston shape, positions of a cylinder operation surface and the piston, specifics shapes of the cylinder and piston, and connecting constitution of the piston to a connecting rod, which solves problems such as occurrence of wear on a cylinder inner surface by displacement of the piston, size enlargement by an increase of a removal capacity, difficulty in processing the piston and connecting rod, and a large top clearance.

Abstract: The purpose of the present invention is to provide a multi-cylinder compressor permitting to increase a gas inflow into the housing without enlarging the intake ports of the bearing plate. The bearing plate 12 bearing the crankshaft 9 is provided with plural intake ports 12a at regular intervals in the circumferential direction. The substantially inversely-dished cover member 14 is mounted on the top of the bearing plate 12, and it not only covers the plural intake ports 12a, but also forms a sealed space S between the cover member and the bearing plate 12, and is further provided with an introducing opening 14a larger than the intake port 12a at the center top of the cover member 14. The introducing opening 14a is fitted with the gas supply pipe 15 to be connected to the gas supply source (not illustrated).

Abstract: A novel fuel pump arrangement comprises cam driven low and high pressure reciprocating plunger pump units. The fuel pump has rotary drive means, a high pressure pump with a pump body which defines a pumping chamber with an annular arrangement of a plurality of pairs of bores extending radially outwardly from a cam axis. A pumping plunger is mounted in each pumping plunger bore for reciprocation. The fuel pump also comprises a single transfer pump for transferring fuel under pressure to the pumping chamber. This transfer pump includes a single transfer plunger mounted within a transfer plunger bore for reciprocation to provide alternating intake and transfer phases of operation of the transfer pump.

Abstract: A method of compressing a compressible fluid, using a hydraulically driven compressor comprising a precompressor, a first cylinder, and a second cylinder. The precompressor receives a low pressure input of compressible fluid and fills the first cylinder to a precompressor output target pressure. A piston within the first cylinder then forces the compressible fluid into the second cylinder. This cycle is repeated until the second cylinder is filled to a first-cylinder output target pressure, whereupon a piston within the second cylinder forces the compressible fluid out of the second cylinder as a high pressure compressible fluid output, typically into some sort of storage vessel. This cycle is repeated until the compressible fluid output pressure reaches a second-cylinder output target pressure.

Abstract: A gas compressor includes a housing, a separating element in the housing, and a piston guided for movement along the separating element by a drive mechanism between two dead center positions. Gas is compressed in a three-stage compression cycle by the piston in three separate gas chambers arranged in series in the housing. Pressure increases in the gas are easily feasible from very low to very high pressures, for instance from 5 to 400 bar, based on a relatively small installation. The gas compressor includes only a few wear parts for low manufacturing and maintenance costs and for fail-safe operation.

Abstract: A novel fuel pump arrangement comprises cam driven low and high pressure reciprocating plunger pump units. The fuel pump has rotary drive means, a high pressure pump with a pump body which defines a pumping chamber with an annular arrangement of a plurality of pairs of bores extending radially outwardly from a cam axis. A pumping plunger is mounted in each pumping plunger bore for reciprocation. The fuel pump also comprises a single transfer pump for transferring fuel under pressure to the pumping plunger bores of the pumping chamber. This transfer pump includes a single transfer plunger mounted within a transfer plunger bore for reciprocation to provide alternating intake and transfer phases of operation of the transfer pump.

Abstract: Method for converting reactive gases which are sucked in at a low inlet pressure and are expelled at a higher outlet pressure by a dry multi-stage pump, in which method the reactive gases are physically and/or chemically converted into nonreactive components at a pressure situated between the inlet and outlet pressure, the conversion taking place, according to the invention, by means of gas discharge. The invention also relates to a dry multi-stage vacuum pump (3) and a plasma scrubber (4) which are particularly suitable for use in the method according to the invention.

Abstract: A compressor which provides for minimum clearance in the compression chamber while substantially reducing the heat normally experienced by the piston during the compression stroke of a compressor of this type. The suction valve(s) of the compressor is concentrically mounted in the piston while the discharge valve(s) is concentrically mounted in a stationary position within the cylinder. Since the high heat of compression occurs at the discharge valve, the piston will be much cooler than in prior art compressors of this type which improves the efficiency of the compressor and which substantially extends the operational life of the piston rings.

Abstract: A multistage vacuum pump is achieved by utilizing a single piston and cylinder assembly having opposite end portions with substantially equal diameters and an enlarged diameter central portion. One end of the cylinder is closed by a valve and a first stage pumping chamber is defined between the valve and the piston. The enlarged diameter portion of the piston has an axial extent less than the axial extent of the enlarged diameter portion of the cylinder to define second and third stage pumping chambers on opposite sides of the enlarged diameter portion of the piston. The three pumping chambers are interconnected by passage means to an inlet and outlet to provide a sequential reduction in pressure. A single drive unit may be connected to a plurality of pumping units for reciprocating the piston in each pumping unit.

Abstract: A cryogenic pump is disclosed for pumping liquified gas from one container to another container or a point of use. The pump comprises a series of chambers and coupling valves for progressively pumping a liquified gas from an inlet end located within and adjacent to the bottom of the container to an outlet conduit. The pump arrangement allows the container to be substantially emptied thereby avoiding waste of the contained liquified gas.

Abstract: There is presented a gas compressor including a housing defining adjacent first and second chambers in axial alignment, a rod extending through the first chamber and into the second chamber, a tubular projection extending from a first end of the housing into the second chamber, a cylindrically-shaped end portion fixed to the rod and disposed slidably upon the projection and within the second chamber, a piston fixed to the rod and slidably disposed within the first chamber, and conduits for admitting gas to the first chamber, transferring gas from one compression stage to another, and discharging compressed gas from the housing.

Abstract: A telescopic manual pump has a first cylinder, a second cylinder received in the first cylinder, a third cylinder received in the second cylinder, a piston slidably received in the third cylinder and a stem linked to the piston. The first cylinder defines a nozzle through a first end and an opening through a second end. The second cylinder defines a first opening through a first end, a second opening through a second end and a piston about the second end thereof. A first limit is attached to the second end of the first cylinder for retaining the piston of the second cylinder in the first cylinder. The third cylinder defines a first opening through a first end, a second opening through a second end and a piston about the second end thereof. A second limit is attached to the second end of the second cylinder for retaining the piston of the third cylinder in the first cylinder. The piston has first and second disks spaced from each other. A plurality of holes are defined through the first disk of the piston.

Abstract: A micro-pump is disclosed for pneumatically causing a bulging/retracting motion of a plurality of micro-diaphragms disposed in an array along a channel through which a fluid is being driven. The pump includes channel means (10) including a first port (11), a second port (12) and a flow-through space (13) providing a communication therebetween; a plurality of diaphragms (21a-21e) disposed in an array along the flow-through space (13); diaphragm support means (20) including a plurality of actuating gas spaces (22a-22e) which opposes the rear surfaces of the respective diaphragms; a plurality of reciprocatory motion means for individually imparting an oscillation of pneumatic pressure to the respective actuating gas spaces (22a-22e), and drive means for driving the reciprocatory motion means for driving motion with phase differences therebetween so that the upper dead center shifts in the direction of the array.

Abstract: A multistage vacuum pump is achieved by utilizing a single piston and cylinder assembly having opposite end portions with substantially equal diameters and an enlarged diameter central portion. One end of the cylinder is closed by a valve and a first stage pumping chamber is defined between the valve and the piston. The enlarged diameter portion of the piston has an axial extent less than the axial extent of the enlarged diameter portion of the cylinder to define second and third stage pumping chambers on opposite sides of the enlarged diameter portion of the piston. The three pumping chambers are interconnected by passage means to an inlet and outlet to provide a sequential reduction in pressure. A single drive unit may be connected to a plurality of pumping units for reciprocating the piston in each pumping unit.

Abstract: A vacuum pump includes a plurality of rotors accommodated in a housing, a plurality of bearings for supporting the shafts of the rotors, respectively, a fluid-suction opening and a fluid-discharge opening formed in the housing, and a motor for driving at least one of the rotors. The pump has a first pump structure section for suction and discharge of gas, the pressure of which is in a viscous flow region, by utilizing change in volume of a space formed by the rotors and the housing. A second pump structure section is provided for transporting gas, a pressure of which is in an intermediate flow region, and gas, the pressure of which is lower than a pressure of the intermediate flow region, by utilizing movement of the space from a suction side to a discharge side of the second pump structure section.

Abstract: A high pressure fluid pumping transformer apparatus has a cylindrical transformer body surrounded by an outer pressure sleeve defining an annular working fluid chamber substantially surrounding the transformer body which receives fluid from an external source. The interior of the transformer body is divided into a central exhaust chamber and axially spaced working chambers at each end thereof. High pressure cylinders mounted in the transformer body at the end of each working chamber have a high pressure chamber spaced axially outward of the working chambers which contains a suction valve. Discharge valves mounted in the outer ends of the transformer body each contain a discharge valve and discharge port. An exhaust outlet extends from the exhaust chamber and is isolated from the working fluid chamber. A plunger reciprocally mounted in the transformer body has a portion which reciprocates in the working chambers and a reduced diameter at each end which reciprocates in the high pressure chambers.

Abstract: A two-stage positive displacement pump (1) is used in particular to operate in conjunction with a turbomolecular pump (2) that can be placed ahead of it in series. The two-stage positive displacement pump (1) is configured as a hybrid pump (3) that has on the medium-entry side a reciprocating pump (5) with a comparatively large displacement area (6), whereby its piston-cylinder space (7) is sealed off with respect to the crank area (8) by means of a sealing membrane (9). Also as a part of this two-stage positive displacement pump (1) which forms the hybrid pump (3), there is placed in series behind the reciprocating pump (5) a diaphragm pump (10), whose displacement area (11) is noticeably smaller compared to that of the reciprocating pump (5).

Abstract: The compressor comprises at least one high-pressure cylinder and piston unit having a piston which is guided in a cylinder liner and which is coupled with a crankshaft by way of a connecting element guided in the cylinder casing along the longitudinal axis of the cylinder. The piston is coupled with the connecting element by way of a mounting permitting movements of the connecting element relatively to the piston transversely of the longitudinal axis. Guidance of the piston is achieved without affect from oscillations of the connecting. The piston cooperates with the liner to bound a lubricant-free annular gap open over the whole longitudinal portion common to the liner and the piston. A dry gap ring seal can therefore be provided between the piston and the liner and ensures that the compression chamber remains seal tight even at pressures of above 60 bar. Preferably, the piston and the cylinder liner are each made of wear-resistant metal or ceramic material.

Abstract: The invention relates to the dry run-high pressure stage of a multistage piston compressor with a piston designed as a tappet (2) guided in the high pressure cylinder (1) and sealed against the compression space of the cylinder (1) by means of self-lubricating sealing elements (3) forming an annular gap together with the working surface, whereby the latter is formed by a material suitable for dry run. According to the invention, the sealing elements having a height conforming at least to their diameter are embodied in the form of at least two cylindrical sealing elements (3), which are loosely placed one on top of the other in the cylinder (1) on the free end of the tappet (2), provided with working surface guides at least in part areas, and have chamfers (6) on the face side.