Abstract: A reciprocating gas horizontal compressor with free lifting piston, which includes a piston with straight ends and inclined compression chambers, a crankcase in which are mounted a crankshaft, a connecting rod fixed to a cross head thru a bolt which alternately drives in a cross-head body a piston rod, and a cylinder body which contains a cylinder liner in which is moving rectilinear and alternatively an improved piston provided with straight ends and compression chambers inclined in areas (m) and (k), with the same angle and in the same plane as a zone (p) from a first cylinder head element and respectively in a zone (n) from a second cylinder head element, and some magnets fixed to the piston and some magnets fixed outside and to a lower part of the cylinder liner, through which the piston is free lifting on the stroke length with reduced friction.

Abstract: A multistage compression system uses refrigerant and oil. The multistage compression system includes a low-stage compressor that compresses the refrigerant, a high-stage compressor that further compresses the refrigerant compressed by the low-stage compressor, refrigerant pipes that-introduce the refrigerant compressed and discharged by the low-stage compressor into a suction part of the high-stage compressor, a pressure reducing element disposed between the refrigerant pipes, an accumulator disposed between the refrigerant pipes at a downstream side of the pressure reducing element and at an upstream side of the high-stage compressor, and an oil discharge pipe. The oil discharge pipe discharges the oil in the low-stage compressor. The oil discharge pipe connects the low-stage compressor and a portion of the refrigerant pipes. The portion of the refrigerant pipes is on a downstream side of the pressure reducing element and an upstream side of the accumulator.

Abstract: A compressor for a compressed-air feed of a compressed-air supply installation, for operating a pneumatic installation, includes: a first compression space; a second compression space; an air feed port; a compressed-air outlet; and a piston having a first face side, which is subjectable to pressure and which is directed toward the first compression space, and a second face side, situated opposite the first face side, which is subjectable to pressure and which is directed toward the second compression space, the first compression space being delimited by the first face side and the second compression space being delimited by the second face side. The first face side includes a full side and the second face side includes a step side. The piston is attached via a connecting rod to a drive. The first compression space and the second compression space are connected to one another via a connecting line.

Abstract: Disclosed is a liquid chromatography solvent pump including a motor, a first piston, a second piston, and a variable output drive system coupling the motor to at least one of the first piston and the second piston. The variable output drive system includes a gearbox configured to provide a non-equal ratio between an input from the motor and an output delivered to at least one of the first piston and the second piston. The first piston and the second piston are configured to deliver a flow of solvent in a liquid chromatography system.

Abstract: A hydraulically operated compressor has a fixed piston and a fixed compression or outer cylinder. A drive or intermediate cylinder is located between the piston and outer cylinder. A compression chamber is formed between the drive cylinder and the outer cylinder. Drive fluid is pumped into and released from an interior chamber in the drive cylinder to reciprocate the drive cylinder. The drive fluid also provides cooling to the interior of the compressor.

Abstract: Air pumps having an assembled configuration and a disassembled configuration. Particular embodiments described herein include air pumps with a reservoir housing that comprises two or more reservoir housing portions. Each reservoir housing portion couples to another reservoir housing portion in the assembled configuration and decouples from that reservoir housing portion in the disassembled configuration to provide for improved storage of the air pump when not in use.

Abstract: A plunger electric fuel pump includes a cylinder; a plunger; a pump body; a movable element to which the plunger is connected; a fixed core provided so as to face the movable element; a rotational core including a permanent magnet; an electric motor configured to rotate the rotational core; and a spring configured to urge the movable element in a direction away from the pump body. The rotational core and the fixed core are provided with a switching portion configured to switch between a first state and a second state when a rotational phase of the rotational core is changed, the first state being a state where the magnetic force of the permanent magnet is not applied to the movable element, the second state being a state where the magnetic force of the permanent magnet is applied to the movable element.

Abstract: A fuel pump includes a plunger that reciprocates inside a cylinder. The fuel pump includes a first movable element connected to the plunger, a second movable element that functions as a counterweight for preventing or reducing vibrations that are created by reciprocation of the first movable element, an electromagnet provided between the first movable element and the second movable element, a magnetic member that is provided between the first movable element and the second movable element and that attracts both the first movable element and the second movable element when the electromagnet is energized, and a first spring that urges the first movable element and the second movable element so as to move away from each other.

Abstract: A fuel pump includes a first plunger that reciprocates in a first cylinder. The fuel pump further includes a first mover connected to the first plunger; a second mover that serves as a counterweight for suppressing vibration that occurs due to reciprocating movement of the first mover; an electromagnet and a magnetic member that are provided between the first mover and the second mover; a plate disposed between the first mover and the second mover; and a third spring and a fourth spring being a pair of springs sandwiching the plate between the third spring and the fourth spring, the third spring and the fourth spring having end portions connected to a housing.

Abstract: A fuel pump includes a plunger that reciprocates in a cylinder. The fuel pump further includes a first mover connected to the plunger, a second mover serving as a counterweight for the first mover, an electromagnet provided between the first mover and the second mover, a first magnetic member provided between the first mover and the second mover, and a first spring urging the first mover and the second mover away from each other. Further, a second magnetic member is provided between both of the electromagnet and the first magnetic member and a first inclined surface of the first mover, while a third magnetic member is provided between both of the electromagnet and the first magnetic member and a second inclined surface of the second mover.

Abstract: A pump for use in pressurizing a cryogenic fluid. The pump may have a barrel, and a boost enclosure disposed around the barrel. The pump may also have a boost plunger disposed inside the barrel and configured to discharge fluid into the boost enclosure. The pump may further have a main plunger disposed inside the barrel and configured to receive fluid from the boost enclosure and to increase a pressure of the fluid.

Abstract: A ventricular assist device includes a pump such as an axial flow pump, an outflow cannula connected to the outlet of the pump, and an anchor element. The anchor element is physically connected to the pump, as by an elongated element. The pump is implanted within the left ventricle with the outflow cannula projecting through the aortic valve but desirably terminating short of the aortic arch. The anchor element is fixed to the wall of the heart near the apex of the heart so that the anchor element holds the pump and outflow cannula in position.

Abstract: This document provides mechanical seals that include one or more rolling diaphragms. In one example embodiment, this document provides double rolling diaphragm seals that are usable in conjunction with various types of equipment including, but not limited to, accelerated life testing systems. In such a context, the double rolling diaphragm seals facilitate high-speed linear modulation of a variable volume pressure vessel, while maintaining precise volumetric control. Such an arrangement can facilitate an essentially frictionless linear actuation system having a long stroke, long service life, and precise volumetric control. In addition, this document provides linear actuator systems that can be used in adverse environmental conditions.

Abstract: A refrigerator and a driving method thereof are disclosed. A primary compressor and a secondary compressor can form independent cycles together with corresponding evaporators so as to reduce unnecessary power consumption. Also, a backflow prevention valve is installed between the primary and secondary compressors to prevent an increase in pressure of the secondary compressor, or an auxiliary heat exchanger is installed at the outlet side of a second evaporator with high temperature to allow heat exchange of an outlet side pipe of a first evaporator with low temperature so as to shift a load of a freezing chamber into a relatively large refrigerating chamber, thereby improving efficiency of the refrigerator. In addition, an oil separator or an oil collection pipe is installed at the outlet sides of the compressors or an oil balancing pipe and an oil balancing valve are installed between the compressors, so as to uniformly maintain an oil amount between the compressors.

Abstract: A multi-stage diaphragm suction pump, includes at least two pump chambers, each having a inlet having at least one inlet valve, and a outlet having at least one outlet valve, and a suction line, which connects the fluid inlets of the pump chambers. Successive pump chambers are connected to one another by at least one connection line such that, when a differential pressure in the suction line is reached/exceeded, the diaphragm pump changes from parallel to an operating mode that is at least also serial. At least one check valve, which opens to a downstream pump stage, is interposed in each of the inflow and outflow regions of the at least one connection line. A suction-side opening or a pressure-side opening of the connection line is arranged in a region of the pump chamber on which a diaphragm associated with the pump chamber rolls first during a pump cycle.

Abstract: A submersible pump includes a fluid-end section, a power-end section, a top connection sub and an umbilical. The fluid-end section includes a tubular fluid-end barrel, an upper piston disposed within the fluid-end barrel bore, and a traveling valve disposed at the upper piston upper end. The power-end section includes a tubular hydraulic cylinder. A lower piston disposed within the hydraulic cylinder bore is connected to the upper piston. The top connection sub connected to the fluid-end barrel upper end has a discharge port and a standing valve disposed below the discharge port. The umbilical includes first and second tubing strings providing fluid communications between a prime mover and the hydraulic cylinder bore below and above the lower piston face, respectively. A third tubing string provides fluid communications between a wellhead and the top connection sub discharge port.

Abstract: A piston member that includes a piston rod provided with a piston serves for reciprocating inside a cylinder barrel, the piston dividing the cylinder barrel chamber into a proximal cylinder barrel chamber having a proximal capped end opposite the piston and a distal cylinder barrel chamber having a distal cylinder barrel end opposite the piston. The piston member has at least one sealing ring or seat arranged inside the distal cylinder barrel chamber at the distal cylinder barrel end. Preferably three consecutive piston members are arranged to operate in a series in an apparatus for transporting coal powder to a gasifier. The movement of the pistons inside the cylinder barrels is controlled in relation to each other to transport apportioned batches of coal powder to a high pressure reactor.

Abstract: A compression apparatus for compressing a fluid, the apparatus having a frame and a motor mounted to the frame, the improvement comprising a drive mechanism installed on the frame so as to be driven by the motor and at least one piston-cylinder unit operably connected to the drive mechanism, the piston-cylinder unit having a cylinder, a piston slidably installed within the cylinder, and a piston rod interconnecting the piston and the drive mechanism so as to shift the piston up and down within the cylinder.

Abstract: A plate pump assembly for pumping various fluids including heavy crude. The plate pump assembly includes first and second chambers each having lower and upper valves. Primary upper and lower eccentric cams within the plate pump assembly are connected to an upper plate and a lower plate. A secondary eccentric cam is connected to a piston that separates the first and second chambers. A drive shaft of the assembly rotates the primary upper and lower eccentric cams to actuate the upper and lower plates alternately concealing and revealing the lower and upper valves for the first and second chambers. The drive shaft further rotates the secondary eccentric cam to actuate the piston alternately decreasing and increasing an area of the first and second chambers to receive fluids through the lower valves and compress the area within the first and second chambers to push the fluids through the upper valves.

Abstract: A reciprocation pump has a supply liquid-side sub-pumping chamber and a waste liquid side sub-pumping chamber for containing and sending out liquid adapted to communicate with the supply liquid-side pumping chamber and with the waste liquid-side pumping chamber, respectively. The supply liquid-side sub-pumping chamber and the waste liquid-side sub-pumping chamber are interlocked with a reciprocation mechanism to vary their volume reversely to that of the volume variation of the supply liquid-side pumping chamber and the waste liquid-side pumping chamber, respectively. The reciprocating motion of the reciprocation mechanism enables the liquid to be supplied to the objective apparatus through the supply liquid-side pumping chamber and the supply liquid-side sub-pumping chamber. Also, it enables the waste liquid from the objective apparatus to be discharged to the outside through the waste liquid-side pumping chamber and the waste liquid-side sub-pumping chamber.

Abstract: A hand operated hydraulic pump has a cam that is pivoted by a compensation cylinder that rotates the cam so as to move the pivot of an operating handle closer to the pump plunger as the output pressure of the pump increases.

Abstract: A high-pressure compressor (1) for compressing gases, which has at least two working spaces (3, 3?) and is optionally adjustable between a single-stage operating position, in which the gas to be compressed is compressed in one single stage, and a multi-stage operating position, in which at least one working space (3?) is connected in series with at least one further working space (3), wherein at least three working spaces (3, 3?) are provided which all have the same working volume.

Abstract: An invention is claimed that enables the pumping of compressible fluids at high pressures when an accurate flow is desired. Two pressure sources, for example pumps plumbed in series, separate thermodynamic work, such as pressurization, at the first pressure source from a volumetric or matter metering function in the second pressure source. One example is a flowstream delivery for a chemical instrumentation system that is manufactured from relatively unsophisticated pumps yet delivers precise flows with low pulsation (<1%) over pressures greater than 100 bar. An advantage of one embodiment allows the economical conversion of typical HPLC systems to state of-the-art supercritical fluid chromatography (SFC) systems with minimal modification to system components.

Abstract: Methods and apparatus for storing high-pressure, high-purity oxygen in a pressure vessel for use in the home health care or related fields as for ambulatory patients, persons confined to wheelchairs, and those who are bedridden. The Oxygen may be produced from air an oxygen-enriched gas and stored in a concentrator product tank. After reaching a predetermined pressure, the gas is fed to a compressor where it is compressed to a high pressure and stored in a mobile or portable high-pressure container. A patient can thus have increased mobility through use of the portable, one or more high-pressure oxygen containers.

Abstract: A multi-stage expansible chamber pump system includes a HP pump unit, and first and second LP pump units. The LP units each include a LP air chamber and a pumped fluid chamber, separated by a piston. The HP unit includes left and right HP air chambers separated by a piston. Pistons are coaxial on a common piston rod for reciprocating movement in unison. A direction control DC valve includes a valve spool movable between first and second positions. The DC valve receives high pressure shop air as Control air and Process air. Control air moves the DC valve spool alternately to first and second positions. The DC valve, as determined by the position of the spool, directs Process air alternately to one side, then the other, of the HP unit, whereby the pistons reciprocate in unison to pump fluid through the fluid chambers.

Abstract: A positive-displacement reciprocating compressor comprising a “non-conventional” crank mechanism which eliminates the amount of frictional force between the wall of the piston and the wall of the cylinder, whose characteristic feature is to have a planet (20) made of sintered material, with self-lubrication properties, allowing to eliminate bushings or similar additional elements. An economical and structurally simple lubrication system, which preferably comprises a classical link rod/crank mechanism, utilizes the mechanical energy provided by the drive shaft of the compressor and sends the lubricant (oil) in a precise manner to the surfaces that need to be lubricated. This oil is easily retained by the very small grains of the sintered material. Moreover, a valve system based on a single plate simplifies the structure of the cylinder unit (30).

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 pump device which accurately detects a flow rate of a pump, performs real-time control of the flow rate, and thus can suppress a flow rate error caused by occurrence of pulsation. Control of a pump rotation speed by a pressure sensor has low responsiveness in a low pressure region, and a correlation between a pressure and a flow rate is incomplete in a high flow rate region. With this taken into consideration, a flow rate sensor is disposed at an outlet port of a second pump. A position detection sensor detects a point where a first pump is shifted from a suction mode to a discharge mode. Moreover, the flow rate sensor detects that there is no discharge from the pump, and that there is discharge from the pump alone. Accordingly, a controller sets a rotation speed of a motor to a speed double the previous speed (double the normal rotation speed).

Abstract: The invention relates to a hydraulic device with a supply line for pressurized hydraulic fluid and with a lubricating pump that is connected to the supply line in a fluidic fashion. The lubricating pump comprises a hydraulic inlet, a pump element for conveying a lubricant from a reservoir to at least one lubricating point of the hydraulic device, and mechanism for producing a pump stroke of the pump element. The mechanism for producing a pump stroke comprises a base body, a piston unit movable in the base body, and a reversing mechanism for reversing the direction of movement of at least one element of the piston unit.

Abstract: A dosing pump comprises an inlet for a solvent, an injection device for an additive, a reciprocating main piston for mixing the solvent with the additive during a suction stroke and for discharging the mixture from an outlet in an evacuation stroke. A divider substantially perpendicular to a rod connected to the main piston separates a main piston housing from a switching device for controlling a main piston stroke direction. The switching device comprises two inlet rotary valve assemblies that are disposed externally to a corresponding inlet aperture bored in the divider when in an opened state and are rotatable about an axis substantially perpendicular to the axis of the main piston. Each of the valve assemblies alternately opens and occludes a corresponding inlet aperture so that solvent flowing through a first inlet aperture performs a suction stroke and solvent flowing through a second inlet aperture performs an evacuation stroke.

Abstract: An improved baffle for a pony rod arm of a two cycle reciprocating pump having a gear end containing gear oil and a fluid end channeling oilfield fluids, provides a spiral cut expanded baffle which may be expanded to be installed on a pony rod arm of the pump without requiring the disassembly of the pump to install the baffle on the rod arm, the expanded baffle compressed and attached together subsequent to installation on the rod arm, the baffle slidably engaging the rod arm to strip the rod arm of liquid residue to prevent contamination of the gear end and the gear oil by the oilfield fluids.

Abstract: A piston pump includes a pump mechanism for changing a volume of a pump chamber to move a piston in a housing, and a feed mechanism that has a feed ring attached to a circular groove portion of the piston to be slaved with a movement of the piston. The feed mechanism is located in a suction passage from a suction port to a pump chamber, and the piston has a flange portion protruding radially outwardly. An inner peripheral surface of the feed ring has an inner-diameter enlarged portion extending radially outwardly to have an enlarged passage portion between the inner peripheral surface of the feed ring and the outer peripheral surface of the piston, and a valve portion for opening and closing a suction passage is constructed of an end portion of the inner diameter enlarged portion of the feed ring and the flange portion.

Abstract: A multi-stage reciprocating compressor includes a cylinder block and a cylinder head. The cylinder block defines a low stage cylinder and a high stage cylinder. The cylinder head is secured to the cylinder block overlying the low and high stage cylinders. The cylinder head defines a mid-stage plenum which is in fluid communication with the low stage cylinder and the high stage cylinder for communicating a working fluid discharged from the low stage cylinder to the high stage cylinder.

Abstract: The invention relates to a converter for converting mechanical energy into hydraulic energy and to a robot implementing said converter. The invention can particularly be used in the production of humanoid robots in which autonomy is to be improved. The converter includes a shaft rotated by mechanical energy about a first axis relative to a casing, a hub comprising a bore formed about a second axis, the shaft rotating in the bore, the two axes being parallel and a distance between the axes forming an excentricity, at least two pistons capable of movement in a radial housing of the shaft, the piston bearing against the bore.

Abstract: A two stage reciprocating compressor includes a casing. A first compressing unit is disposed in the casing and includes a first piston and a first cylinder, the first compressing unit being driven by a reciprocating motor to linearly reciprocate the first piston in the first cylinder to suck in and compress gas. A second compressing unit is disposed in the casing and includes a second piston and a second cylinder, the second compressing unit being driven by vibration of the first compressing unit to linearly reciprocate the second piston in the second cylinder to suck in and compress gas. A vibration transfer member transfers the vibration from the first compressing unit to the second compressing unit. The first and second compressing units extend in parallel and face toward each other.

Abstract: This invention provides a swing-type reciprocative compressor capable of maintaining long durability and preventing propagation of heat to the large end portion of a piston, even under high-compression. In the reciprocative compressor having a swing-type piston mechanism, a piston ring is attached to a piston ring groove to seal between a piston and a cylinder. A ring groove is provided separately from the piston ring groove on the outer circumferential side of the piston and on the crankshaft side of the piston ring groove. A guide ring restricted from moving in a radial direction and shaped like a skirt opening toward the crankshaft side is provided in the ring groove.

Abstract: The invention relates to a cooling device for a compressor 100 which is provided with an intermediate heat exchanger 112 and an output heat exchanger 102 for cooling of compressed gas. The cooling device is enclosed by a jacket 200. The jacket has an air intake opening 202, connected to a radial fan 105 which provides an overpressure inside the jacket 200. The heat exchangers 102, 112 are mounted in air outlet openings 204, 206 in the jacket, with the result that the overpressure in the jacket 200 leads to cooling of the heat exchangers 102, 112. The jacket further comprises an additional outlet opening 208 for discharge of air used for cooling other elements of the compressor, such as cylinder walls, covers/tops and crankcases. The relationship between the different cooling processes can be influenced by the design of the openings 204, 206, 208 in the jacket 200.

Abstract: A fluid content monitor including a cuvette, a calorimeter adapted to generate a signal indicative of contents of a fluid sample contained in the cuvette, a container for holding a reagent, and a pump assembly for delivering reagent from the container to the cuvette. The pump assembly includes a tube extending from the container to the cuvette, check valves preventing reverse flow in the tube, and a hammer driven by a solenoid for repetitively compressing the tube to pump reagent to the cuvette. The cuvette can be removed for cleaning and replacement.

Abstract: A two stage reciprocating compressor includes a casing. A first compressing unit is disposed in the casing and includes a first piston and a first cylinder, the first compressing unit being driven by a reciprocating motor to linearly reciprocate the first piston in the first cylinder to suck in and compress gas. A second compressing unit is disposed in the casing and includes a second piston and a second cylinder, the second compressing unit being driven by vibration of the first compressing unit to linearly reciprocate the second piston in the second cylinder to suck in and compress gas. A vibration transfer member transfers the vibration from the first compressing unit to the second compressing unit. The first and second compressing units extend in parallel and face in the same direction, the second compressing unit being located adjacent to a suction passage of the first compressing unit.

Abstract: The high-pressure generation device (110) comprises three pressure chambers which pressurize liquid drawn from the outside through the pumping operation of a plurality of pistons (1) having different outer diameters, pressurizes the liquid drawn from the outside, and discharges the liquid pressurized to a constant pressure to the outside in each reciprocating operation of the plurality of pistons (1). The three pressure chambers comprising a first pressure chamber (31) which draws liquid from the outside, a second pressure chamber (32) of which the pressurizing area for pressurizing the liquid is smaller than that of the first pressure chamber (31), and a third pressure chamber (33) of which the pressurizing area is smaller than that of the second pressure chamber (32) and which discharges liquid to the outside.

Abstract: A refrigerant recovery machine having two opposed and off-set pistons and its use are provided. The pistons are received in cylinders that are able to move depending on the alignment of the pistons. The two pistons in the compressor allow more volume of refrigerant than a single piston and because they are opposed and off-set allows for more even load on the motor.

Abstract: The invention relates to a compressor (1) for gaseous and/or cryogenically liquefied media comprising a first compressor piston (6) and a second compressor piston (7), which are operatively connected to an eccentric shaft (2), wherein the second compressor piston (7) is arranged substantially opposite to the first compressor piston (6) relative to the eccentric shaft (2). To solve the object of providing such a compressor with a small space requirement and low construction costs, it is proposed according to the invention for the compressor (1) to be embodied as an oscillating piston-type compressor, wherein the first compressor piston (6) is arranged on an eccentric ring (4), which is effectively connected to the eccentric shaft (2) and wherein the second compressor piston (7) is fastened to a pivot lug (8), which is effectively connected to the eccentric ring (4).

Abstract: A pumping apparatus (200) for delivering liquid at a high pressure (Psys) at which compressibility of the liquid becomes noticeable, comprises a piston (20) adapted for reciprocation in opposing directions in a pump working chamber (30), and a drive (40) coupled to the piston (20) to apply a tension force onto the piston (20) in order to move the piston (20) into a drive direction (50).

Abstract: In a tandem piston pump (1) from which pump discharge pressure from four systems is extracted, a tilt axis direction of a front swash plate (14) and a tilt axis direction of a rear swash plate (54) are different to each other, respective discharge ports (23, 24) of a rear pump (50) are opened at a phase difference relative to respective discharge ports (21, 22) of a front pump (10), and respective pump ports (41, 42) of the front pump (10) and respective pump ports (43, 44) of the rear pump (50) are opened in different side faces (71, 72) of a port block (70).

Abstract: A compressor has a housing. A crank is carried by the housing for rotation about a crank axis. A cylinder is defined within the housing and has a proximal portion and a distal portion. The distal portion is smaller in transverse cross-sectional area than is the proximal portion. A piston is held within the housing for reciprocal movement at least partially within the cylinder. The piston also has a distal portion smaller in transverse cross-sectional area than a proximal portion. A connecting rod is pivotally coupled to the crank for relative rotation about a proximal axis and to the piston for relative rotation about a distal axis. A first compression chamber exists in the cylinder distal portion beyond the end of the piston. A second compression chamber exists in the cylinder proximal portion beyond a piston shoulder. The first and second compression chambers are non-series and non-parallel.

Abstract: A piston pump includes a first piston pump including a first piston and a first pump chamber, a second piston pump including a second piston and a second pump chamber, the second piston operating to follow the first piston, a pressure release passage formed in communication with the second pump chamber, and a relief valve provided at the pressure release passage and defining an upper limit discharge pressure of the second piston pump. When a discharge pressure of the second piston pump is equal to or smaller than the upper limit, a discharge fluid of the second piston pump is added to that of the first piston pump so as to flow into an outlet port. When the discharge pressure exceeds the upper limit, the discharge fluid is released to the pressure release passage and the discharge fluid of the first piston pump only flows to the outlet port.

Abstract: A high pressure pump includes a pump housing. A piston rod located within the pump housing defines a plurality of pump cavities and a plurality of piston cavities. Movement of the piston within the piston cylinder pumps the fluid from the piston cavities out of the high pressure pump. The continuous pumping of HWBF from the pump housing provides fluid at a relatively constant flow and pressure. The HWBF pressure is also at a higher pressure than traditional single stage high pressure pumps can provide.

Abstract: An invention is claimed that enables the pumping of compressible fluids at high pressures when an accurate flow is desired. Two pressure sources, for example pumps plumbed in series, separate thermodynamic work, such as pressurization, at the first pressure source from a volumetric or matter metering function in the second pressure source. One example is a flowstream delivery for a chemical instrumentation system that is manufactured from relatively unsophisticated pumps yet delivers precise flows with low pulsation (<1 %) over pressures greater than 100 bar. An advantage of one embodiment allows the economical conversion of typical HPLC systems to state of-the-art supercritical fluid chromatography (SFC) systems with minimal modification to system components.

Abstract: A positive-displacement reciprocating compressor comprising a “non-conventional” crank mechanism which eliminates the amount of frictional force between the wall of the piston and the wall of the cylinder, whose characteristic feature is to have a planet (20) made of sintered material, with self-lubrication properties, allowing to eliminate bushings or similar additional elements. An economical and structurally simple lubrication system, which preferably comprises a classical link rod/crank mechanism, utilizes the mechanical energy provided by the drive shaft of the compressor and sends the lubricant (oil) in a precise manner to the surfaces that need to be lubricated. This oil is easily retained by the very small grains of the sintered material. Moreover, a valve system based on a single plate simplifies the structure of the cylinder unit (30).

Abstract: A multi-stage piston compressor is provided with at least two piston-cylinder units, which respectively comprise a separate linear drive for moving the piston. A control device is also provided, which is designed in a manner such that the linear drives may be controlled individually with regard to speed and stroke.