Abstract: A linear compressor motor comprising a piston assembly (2) and a cylinder assembly (3) mounted together for relative axial movement along an axis (1) by a pair of spiral springs (16, 17). The piston assembly (2) includes a piston (6) and the cylinder assembly (3) including a cylinder (4), there being a low clearance between the cylinder and the piston to enable a pumping action to be achieved without seals. Mounted on the exterior of the cylinder (4) is a magnet (13) and associated polepiece (14). Forming part of the cylinder assembly (3) is a cylindrical housing (11) in which the cylinder itself is mounted by means of a radially-extending flange (12). The coil for interaction with the magnet is positioned in an annular air gap between the polepiece (14) and the housing (II). The coil is wound on a coil holder (8) which is itself mounted on the piston (6) by way of a radially-extending flange (7).

Abstract: A pump including a first enclosure (10) and a second enclosure (20), a pumping mechanism (3) and an electromotive means (11,23) operable to drive the pumping mechanism (3). The electromotive means (11,23) includes a solenoid assembly (11) having a solenoid coil (13), and an armature assembly (23), the solenoid coil (13) being sealed within the first enclosure (10). The pump mechanism (3) is supported within the second enclosure (20), the armature assembly (23) being in operational relationship with the pumping mechanism (3). A diagnostic sensor (19) is sealed within the first enclosure (10) for detecting flow through a flow path (22) in the second enclosure (20). A flow responsive member (28) is supported within the flow path (22), the diagnostic sensor (19) detecting displacement of the flow responsive member (28).

Abstract: A reciprocating compressor with a linear motor, comprising a hermetic housing (10), which lodges a cylinder (20), a piston (30); a rod (40), which is coupled to the piston (30) and which is axially displaceable by a linear motor (50); a first supporting means (70) and a second supporting means (80), which are elastically deformable and coupled to the housing (10) and, respectively, to the cylinder (20) and to the rod (40), and which are electromagnetically displaceable in opposite directions, in order to provoke the axial displacement of the cylinder (20) and of the piston-rod assembly (30, 40) between the upper and lower dead point positions.

Abstract: A linear compressor according to the present invention introduces a direct suction system by extending a gas suction pipe to an inside of a piston of a compressor unit to thereby minimize gas suction loss of the linear compressor and also reducing manufacturing costs and includes elastic support means necessary for vertically disposing the linear compressor in order to more effectively apply the direct suction system. According to the present invention, there is provided a compressor including a predetermined-shaped hermetic vessel, a compressor unit disposed in the hermetic vessel without having mufflers, a gas suction pipe extendedly formed to an inside of a piston of the compressor unit, an oil supply means for supplying oil into a cylinder of the compressor unit and elastic support means provided at upper and lower parts of the hermetic vessel for elastically supporting the compressor unit.

Abstract: The invention relates to a lubrication system for a mechanism (27), on-board a spacecraft. It comprises a non pressurized tank (20) communicating with the mechanism (27) via a tube (220). A piston (23) closes the tube (220) while the mechanism is at rest. The piston (23) is controlled by a first spring (5) and by a second, shape memory, spring (24) opposing the latter, which lengthen by thermal effect. A controller (25, 26) supplies this spring with a current (I) to actuate it. An annular element(7), pushed by a cylindrical spring (6), defines a capillarity filled pumping chamber (22). When the temperature of the shape memory alloy (24) falls back below a threshold, the spring (24) recovers its original shape, the first spring (5) pushes back the piston (23) and expels a dose of lubrication fluid (4).

Abstract: There is disclosed a stator of a linear compressor which comprises a bobbin of a cylindrical shape having a recess for winding coils at the outer circumference thereof, coils wound in the coil winding recess, and a plurality of cores inserted into the bobbin. A plurality of guide rails extending to the axial direction of the bobbin are arranged radially at regular intervals on the inner circumference of the bobbin and the cores are mounted between the respective guide rails. Further, a plurality of guide projections extending outward from the outer circumferences of the upper and lower ends of the bobbin are arranged at regular intervals. In addition, there are further provided a plurality of supporting jaws extending toward the inside of the bobbin between the respective guide rails.

Abstract: A vibrating compressor which may be employed in refrigerators is provided which includes an elastic mechanism designed to produce reaction against movement of a piston through a moving mechanism such as an electric motor to oscillate the piston to change the volume of a compression chamber. The elastic mechanism consists of a plurality of discs connecting at the center with the piston. Each of the discs has slits curved in a scroll fashion to form spring arms. The discs are laid to overlap each other and shifted in angular position from each other so that the arms of one of the discs coincide with the slits of adjacent one of the discs, thereby avoiding direct contact of the arms of adjacent two of the discs.

Abstract: A coolant supply apparatus for a linear compressor which includes a stator mounted at one side of a flange for generating a magnetic field therearound and a horizontal operating unit which reciprocates horizontally. The horizontal operating unit includes a magnet disposed inside the stator and a piston, which is integral with the magnet and reciprocates horizontally within a cylinder. The coolant supply apparatus further includes a coolant oil pocket for guiding a predetermined amount of coolant oil to an outer circumferential surface of the cylinder in cooperation with a suction force of the piston and for cooling a heat generated in the cylinder. A plurality of coolant oil sucking/discharging holes are formed at the cylinder in order for the coolant oil filled in the coolant oil pocket to be introduced between the cylinder and the piston therethrough.

Abstract: An electromagnetic reciprocating compressor has a body (1, 2), a piston (10) reciprocating in the body, and an electromagnetic drive (22, 23, 24) for the piston. The piston has a piston head (11) which slides in a cylinder (12) in the body to effect compression of fluid in the cylinder during operation of the compressor and, axially spaced from the piston head, a piston guide member (13) slidingly movable on a guide surface (14) provided by the body. The compressor has a compression spring arrangement (20) comprising at least one helical compression spring (20a, b) acting to drive the piston axially. The spring (20a, b) is mounted around the piston and is at least partly located within the cylinder during at least part of the piston stroke but is outside the working volume of fluid undergoing compression.

Abstract: An improved oil supply apparatus for a friction portion of a linear compressor which is capable of enhancing the lubricating performance of the piston by substantially supplying oil to the fricton portion between a cylinder (122') and a piston (129), thus enabling a desired reciprocating movement of the piston (129), which includes a cylinder (122') having a plurality of oil introducing holes (122a) for communicating the inside and the outside of the cylinder (122'); an oil mass (131) disposed between the cylinder and a core liner spaced apart from the cylinder (122') and slidable whithin an oil pocket (132) communicating with the cylinder (122') by an oil suction hole (143c); an elastic member (133, 134) for elastically supporting the oil mass (131); and a valve assembly (139') for a refrigerant gas flowing path for guiding the flowing of the refrigerant gas, a suction gasket (141) integral with an oil flowing path for guiding the flowing of the oil supplied to and discharged from the friction portion betwee

Abstract: In order to enable the production of the motor shaft to be simplified in the case of a high-pressure cleaning device comprising a piston pump, the pistons of which are driven by a motor via a wobble plate non-rotatably connected to the motor shaft of the motor, it is suggested that the wobble plate be non-rotatably connected by means of form locking to a coupling element consisting of plastic, this coupling element being attached at its end face to the motor shaft circular in cross section and being tensioned against the end face of the motor shaft by a tension rod held in the motor shaft, thereby forming a friction contact.

Abstract: An oscillating pump (10) includes a housing (11) which carries the components thereof. These components include an electromagnetic coil (24) surrounding an armature (23) carried by an impeller (12) which is positioned longitudinally between an inlet area (16) and an outlet area (17) of the pump (10). The armature (23) moves longitudinally upon activation of the coil (24) to the point of the greatest magnetic force generated by the coil (24). The impeller (12) includes a pair of bellows (19, 20) and carries a valve (13). The bellows (19, 20) define an inlet chamber (21) and a discharge chamber (22). Another valve (15) is carried by the housing adjacent to the discharge chamber (16). Upon activation of the coil (24) the valve (13) forces fluid in the discharge chamber (22) through the valve (15) and allows fluid to pass from the inlet chamber (21) to the discharge chamber (22) upon deactivation of the coil (24).

Abstract: An electromagnetic pump having an electromagnet carried by the housing external to the fluid chambers, and an armature moveable in the housing having a pole magnetically attracted by the electromagnet and a piston to force fluid out of the chambers and through the pump outlet. A path provides controlled bypass for bubbles in the fluid around the armature piston between the fluid pumping chamber and the fluid receiving chamber only during the return stroke of the armature. Fluid inertia is reduced by an outlet orifice in the path of fluid flow from the pump outlet and by a bypass orifice for fluid flow in the bypass path, the orifices being provided either individually or in combination depending upon the fluid flow characteristics of the system including the pump. An accumulator in the fluid flow path between the pump outlet and a catheter leading away from the pump alleviates inertial and viscous effects arising from the catheter.

Abstract: A mechanically pumped heat pipe having an evaporator section and a condenser section disposed at a location below the evaporator section. A solenoid actuated cavitation-free mechanical pump returns a working fluid from the condenser section to the evaporator section. An armature connected to the piston head of the mechanical pump is disposed inside the condenser section and the solenoid coil is disposed outside of the condenser section in the vicinity of the armature permits the piston head to be periodically reciprocated without any electrical or mechanical feedthroughs.

Abstract: The modular linear motor includes at least a pair of like stator modules and at least a pair of like mover modules. A stator module coupler interconnects the like stator module and has an axial length of sufficient dimension to maintain a given three phase stator pole pitch between the interconnected stator modules. A mover module coupler interconnects the like mover modules, and has another axial length of sufficient dimension to maintain a given mover pole pitch between the interconnected mover modules.

Abstract: A compressor (10; 100; 200; 300; 500) with a build-in reciprocating motor, comprises a cylindrical housing (20; 120; 210; 510) with two ends thereof fitted with two opposing electromagnets (30; 130; 230; 530), each has a circular inner pole (36; 136) and a coaxial annular outer pole (34; 134). A free piston (50; 150; 250; 560; 600) is disposed in the housing between the two electromagnets, dividing the interior of the housing into two chambers (I, II). The piston carries permanent magnet (40; 140, 145; 561; 610), providing inner and outer poles (44, 46; 141, 146) which have conical surface portions (43, 49; 141, 146) complementary with the corresponding poles (34, 36; 134, 136) of the electromagnets. Sliding pole pieces (630 and 660) can be used to increase the stroke length and reduce the piston's total weight. Valves (61, 63, 65; 161, 165) are fitted to form one-way flow passage connecting the inlet and the outlet of the compressor.

Abstract: An electromagnetic pump has a solenoid reciprocating a piston that abuts the ball of a first, one-way ball valve coaxially aligned with the piston axis. In the abutting position the piston closes the valve and provides a pump chamber of very small volume. An second, one-way outlet valve is located orthogonal to the first valve to provide a compact structure and further minimize the volume of the pump chamber. A plurality of these inlet valves can be arranged so the pistons are parallel and activated by a single, solenoid activated piston, with the outlet valves being radially orientated to provide a compact structure that simultaneously provides precise fluid amounts to a plurality of locations, such as multiple pistons of a two cycle engine.

Abstract: An electromagnetic pump comprising a housing having fluid receiving and pumping chambers in communication with an inlet and outlet, respectively, an electromagnet carried by the housing external to the fluid chambers thereof, and an armature movable in the housing having a pole portion magnetically attracted by the electromagnet and a piston portion to force fluid out of the chambers and through the pump outlet. A path provides controlled bypass for bubbles in the fluid around the armature piston portion between the fluid pumping chamber and the fluid receiving chamber only during the return stroke of the armature.Fluid inertia is reduced by an outlet orifice in the path of fluid flow from the pump outlet and by a bypass orifice for fluid flow in the bypass path, the orifices being provided either individually or in combination depending upon the fluid flow characteristics of the system including the pump.

Abstract: A microfabricated, remotely actuated fluid pump includes a LIGA-fabricated movable member disposed within a cavity. The LIGA-fabricated movable member and the cavity cooperate to (a) define a sufficiently small clearance therebetween to achieve effective pumping action while (b) presenting a sufficiently low-friction fit to enable remote actuation. Such a pump can take the form of a piston pump, a vane pump, a centrifugal pump, a gear pump, etc. Other fluidic devices including flow sensors, piston valves, hydraulic motors, nozzles, and connectors can be fabricated using similar principles.

Abstract: Disclosed herein is a fuel pump comprising a housing including therein a high pressure fuel chamber, a fuel outlet valve communicating with the high pressure fuel chamber and being operable to prevent fuel inflow and to permit fuel outflow when the fuel pressure is above a predetermined level, a fuel inlet valve communicating with the high pressure chamber and being operable to prevent fuel outflow and to permit fuel inflow, and a bearing bore extending from the high pressure chamber, a rod slideably and sealingly supported in the bearing bore for movement relative to a retracted position, and structure located in the housing for displacing the rod from the retracted position and in the direction toward the high pressure fuel chamber through an initial stroke length without encountering substantial resistance and thereafter displacing the rod through a subsequent stroke length which is effective to highly pressurize the fuel in the high pressure fuel chamber.

Abstract: A linear compressor includes a casing, and a cylinder member suspended by springs from the casing. The cylinder member forms a compression chamber in which a piston is reciprocated by a linear motor. The motor includes a first stator situated inside of the piston, and a second stator situated opposite the first stator outside of the piston. The cylinder member comprises spaced apart first and second cylinder blocks with the second stator clamped therebetween. The first cylinder block contains the compression chamber, and the second cylinder block carries a hollow guide extending into the piston, with the first stator mounted on an outer surface of the guide. The piston includes an axial shaft reciprocally guided within the hollow guide. The piston carries a first magnet. A coil disposed between the first and second stators generates a magnetic field passing across the magnet to cause the piston to reciprocate.

Abstract: In a method of driving vibrating compressors having such a construction that a-c voltage is fed to a vibrating compressor by converting d-c voltage into a-c voltage with two MOS-FETs, the two MOS-FETs as switching elements are driven to convert d-c voltage into a-c voltage by changing the ON time of each of the MOS-FETs corresponding to suction and compression strokes in one cycle of the vibrating compressor to improve the operating efficiency of the vibrating compressor. To this end, suction and compression time in one cycle of the vibrating compressor is changed by means of a timer IC.

Abstract: An electromagnetic reciprocating compressor has a body (1, 2), a piston (10) reciprocating in a cylinder (12) in the body and a piston guide (14) in the form of an insert which is radially located relative to the axis of the cylinder (12) by fitting against a registration surface (25a), the registration surface is on a body part (1) which also provides the internal cylinder surface (12a) of the cylinder. To improve the alignment of the insert (14), the registration surface (25a) and the internal cylinder surface (12a) are formed to their respective final diameters in the same machining operation by reference to a common axis. The piston guide (14) is axially located related to the cylinder (12) by being resiliently clamped between the stator (23) and an end portion (27a) of the body (1, 2) opposed to the stator (23) with a resilient member (27) interposed between the body end portion (27a) and the piston guide (14).

Abstract: A positive displacement inductive pump includes a housing having first and second ends, and a bore extending from the first end to the second end. A piston is positioned entirely within the bore and defines at least one substantially enclosed displacement chamber. The piston includes a metal rod, and a corrosion resistant lining that completely encapsulates the metal rod. First and second inductive coils are each wrapped around an outer circumference of the housing and are each alternatingly energizable to produce respective first and second induced magnetic fields causing metal piston to move to oppositely located first and second positions within the bore. At least one check valve assembly is attached to one of the first and second ends and is in communication with the at least one displacement chamber.

Abstract: A vibrating compressor having a housing with an inner tube and an outer tube formed concentrically. The inner tube is connected with the outer tube via an end plate. The end plate being disposed at one axial end of the inner tube and the outer tube to form a housing closed end and a housing open end. A permanent magnet is fitted to an inner circumferential surface of the outer tube. A driving coil is provided in a gap between the permanent magnet and the inner tube. A cylinder is fitted into an inside of the inner tube and a hollow piston equipped with a valve is inserted into the cylinder. The hollow piston is connected to the driving coil via a bobbin and is supported by support springs in such a manner as to perform reciprocating motion. A cylinder head connected to the housing forms a compression chamber at an end of the cylinder and compressed fluid is discharged from the compression chamber by the reciprocating motion of the piston.

Abstract: A hydraulic pump has a magnetic tube and two floating pistons within the tube, adapted to be moved in an axial direction within the tube as a result of magnetic flux generated by an electric coil surrounding the tube. Each piston has a valve for allowing fluid flow in one direction through the tube, and spring means acts on the pistons to control their positions. The arrangement allows operation with reduced vibration and pressure fluctuation, less heat and impact during dry running operation, and less heat and impact during high pressure shut-off.

Abstract: The present invention provides a pump for inducing a displacement of a fluid from a first medium to a second medium, including a conduit coupled to the first and second media, a transducing material piston defining a pump chamber in the conduit and being transversely displaceable for increasing a volume of the chamber to extract the fluid from the first medium to the chamber and for decreasing the chamber volume to force the fluid from the chamber to the second medium, a first transducing material valve mounted in the conduit between the piston and the first medium and being transversely displaceable from a closed position to an open position to admit the fluid to the chamber, and control means for changing a first field applied to the piston to displace the piston for changing the chamber volume and for changing a second field applied to the first valve to change the position of the first valve.

Abstract: An internal combustion engine including an engine block including a cylinder head defining a combustion chamber and having therein an opening communicating with the combustion chamber, and a combined fuel injection pump and nozzle including a housing fixed to the cylinder head and defining a high reluctance gap and a low pressure fuel chamber having an axis, a tubular member extending in the housing into the low pressure fuel chamber in coaxial relation to the axis, having therein an axial bore communicating with the low pressure fuel chamber, and at least partially defining a high pressure fuel chamber, and a nozzle assembly fixed to the housing, extending into the opening, communicating with the combustion chamber and with the axial bore, and including a valve member moveable to an open position in response to a fuel pressure in the high pressure fuel chamber above a predetermined level.

Abstract: Oil-well installation extending from the surface (14) to an oil-bearing rock stratum (16) comprising a tubing (20), arranged in the well and forming a flow channel to the surface for hydrocarbons originating from the oil-bearing rock stratum, a casing (18) delimiting the wall of the well, and a seal (24) arranged at the well bottom between the tubing (20) and the casing (18) so as to form a chamber (26) isolated from the hydrocarbons, the installation furthermore comprising, in the well, a pump (30, 48) and an electric motor (34, 46) which is intended to actuate the pump. According to the invention, the stator (40, 52) of the electric motor (34, 46) is arranged outside the tubing (20) and isolated thereby from the hydrocarbons flowing inside the tubing.

Abstract: An electromagnetic disk pump which has a reciprocating member in the form of a rigid ferromagnetic disk. An elastomeric spring, in the form of a short cylindrical tube, is interposed between the reciprocating disk and an electromagnet. The elastomeric spring seals the space between the rigid disk and the electromagnet, thus forming the pump chamber. The electromagnet is used to vibrate the reciprocating disk thereby pumping the fluid contained within the pump chamber. Check valves regulate the fluid flow through the inlet and outlet of the pump chamber.

Abstract: An electromagnetic reciprocating compressor has a body (1, 2), a piston (10) reciprocating in a cylinder (12) in the body and a piston guide (14) in the form of an insert which is radially located relative to the axis of the cylinder (12) by fitting against a registration surface (25a), the registration surface is on a body part (1) which also provides the internal cylinder surface (12a) of the cylinder. To improve the alignment of the insert (14), the registration surface (25a) and the internal cylinder surface (12a) are formed to their respective final diameters in the same machining operation by reference to a common axis. The piston guide (14) is axially located related to the cylinder (12) by being resiliently clamped between the stator (23) and an end portion (27a) of the body (1, 2) opposed to the stator (23) with a resilient member (27) interposed between the body end portion (27a) and the piston guide (14).

Abstract: An electromagnetic linear compressor has a linearly reciprocating piston (10) biased in one direction by a helical coil spring system. A rotational bearing (40) supports one end of the spring system (20a, 20b). To avoid uneven wear due to forces applied by the spring system, the spring system comprises two helical coil springs (20a, 20b) acting in series to bias the piston (10), and the rotation bearing (40) transmits thrust between the two springs while permitting relative rotation of the two springs about their common axis. The compressor also has a turbine (30) for exerting a unidirectional rotational force to rotate the piston (10) about its axis gradually during operation of the compressor.

Abstract: Disclosed is an electromagnetic pump, in which oil is exhausted not intermittently but constantly with small pressure fluctuations, with reduced operational noise, with reduced fire-extinction delay, and improved energy efficiency. The electromagnetic pump has an automatic exhaust-control valve having a conical head, and a cylindrical body having a tapered shape whose diameter decreases rearward from the conical head. According to change of a sectional area of an oil path defined between the exhaust-control valve and an exhaust chamber, the exhaust-control valve transmits an elevated pressure of pressurized oil to a development section to thereby automatically control its pressure elevating capability.

Abstract: A valve assembly is disclosed for an oscillating pump of the type having a reciprocating armature carrying an impeller that defines a pump chamber for flow of fluid through the pump. The valve assembly includes a valve body mounted to the impeller, a valve seat attached to the valve body, a spring retainer, a spring mounted to the spring retainer and a plug located between the spring and the valve seat. The valve assembly provides a substantially fluid tight seal when the pump is discharging fluid and allows fluid to enter the pump chamber when the pump is suctioning. All wetted components are particularly suitable for corrosive fluids, such as acids.

Abstract: A fuel injection pump driven by an electric coil, the pump including a poppet valve slidable within a fuel passage in an armature structure and relative thereto in response to movement of the armature structure relative to the pump housing and through a stroke length between a first position permitting flow in a fuel passage from a low pressure fuel chamber to a high pressure fuel chamber, and a second position preventing fuel flow between the high and low pressure fuel chambers, and comprising a head portion located in the high pressure fuel chamber and including a valve surface which is spaced from the valve seat when the poppet valve is in the first position permitting fuel flow from the low pressure fuel chamber to the high pressure fuel chamber, and which is sealingly engaged with the valve seat when the poppet valve is in the second position preventing fuel flow between the high and low pressure fuel chambers, an adjustment member extending in a bore in the housing wall and being engageable with the pop

Abstract: A piston end position limiter for a free piston machine of the type having a piston sealingly reciprocating in a cylinder and separating a work space bounded at one end of the piston from a second space bounded at the opposite end of the piston. The work space and the second space contain a working fluid having an average pressure. A first valve is connected in communication between a fluid reservoir and the work space and is adapted to open only when the working fluid pressure varies sufficiently in one direction from its average pressure. A second position responsive valve is connected between the reservoir and the second space and is operatively linked to the piston for opening in response to the piston reaching a selected end limit of its reciprocation.

Abstract: A DC-powered controller for a linear pump or motor is provided. The linear pump or motor is of the type that is includes a magnetic permeable member which is attracted to one end of a housing when a power coil is energized, and attracted to the other end of the housing when a reset coil is energized. The controller is connected to and powered by a DC-power source, such as a battery, and includes a voltage regulator, a control signal generator, and a dual coil driver circuit. The voltage regulator converts the battery voltage of the DC-power source to an operating voltage. The control signal generator is powered at the operating voltage and generates a square wave signal. The dual coil driver circuit receives the square wave signal and energizes the power coil during one phase of the square wave, and energizes the reset coil during the other phase of the square wave.

Abstract: A reciprocal type of pump structure wherein a piston has a linear function actuated by a pair of coils energized alternately and includes a plurality of tapered flutes. A check valve in an outlet of the structure which stretches to open said outlet under the impact of expelled fluids and of its own volition retracts to the closed position immediately upon the cessation of fluids being expelled.

Abstract: A magnetic fluid pump prevents the generation of particles and impurities, and is useful where particles and impurities are to be kept to a minimum, for instance in a resist coating process for manufacturing a semiconductor device. A pair of solenoid coils are wound on the outer surface of both of the ends of a a fluid transporting pipe. Inside the transporting pipe is a magnetic cylinder having a valve attached to one end which opens and closes the fluid path. The magnetic cylinder reciprocates back and forth inside the transfer pipe by changing the current direction of the coils. Fluid can be pumped continuously by reciprocation of the magnetic cylinder. The pump suppresses the generation of particles and impurities. When used in a resist coating process, the formation of a resist pattern having a poor profile during the photolithography processing can be prevented.

Abstract: A method of measuring the distance at closest approach between the piston of a free piston compressor and the cylinder head. The method derives measurements of both the alternating and average components of piston position from direct measurements of the voltage and current applied to the linear permanent magnet motor that drives the piston, and thus eliminates any requirement for an additional position sensor located within the compressor.

Abstract: A piston diaphragm pump operable for delivering doses of liquids such as surfactants, or wetting agents, for example, includes a pump piston that is reciprocally moveable within a pump tube that encloses a pump pressure chamber. The pump piston is electromagnetically driven against the force of a return spring by a magnetic coil that surrounds the pump tube. In addition, a pump diaphragm is rigidly clamped about an inner circumference to a portion of an upper end of the pump piston. The outer circumference of the pump diaphragm is rigidly clamped about its periphery between upper and middle housing sections. One side of the diaphragm faces a suction chamber, and the other side faces a pressure chamber. A longitudinal bore, that encloses a pump piston provided with a piston valve, extends centrally through the pump diaphragm and links the pressure chamber to the suction chamber.

Abstract: A movable magnet type pump, wherein a magnet moving body having at least one axially magnetized permanent magnet and an axially extending through liquid passage is arranged so as to be slidable inside a liquid introducing chamber; a plurality of coils are fixed so as to enclose the liquid introducing chamber; a first check valve is arranged on a liquid introducing side of the liquid introducing chamber; a second check valve is arranged on a liquid discharge side of the through liquid passage; and the magnet moving body is caused to reciprocate by interaction between current applied to the respective coils and magnetic flux from the magnet moving body cutting across the respective coils.

Abstract: A fluid pumping apparatus for producing fluid from a well through production tubing comprises an elongate hollow body to be disposed in a well bore and at least partially submerged in fluid to be produced from the well, the body including a fluid inlet valve at its lower end for flow of fluid into the body, a plunger assembly disposed in the interior of the body for reciprocating movement relative thereto, sealing means cooperating with the plunger assembly to divide the body into isolated lower and upper chambers and to isolate the body from the production tubing, and fluid flow control valves operationally synchronized so that fluid is forced up the production tubing upon downstroke of the reciprocating plunger assembly in the body of the pumping apparatus. A method of pumping fluid utilizing the apparatus of the invention to produce fluid on the downstroke of the plunger assembly is also provided.

Abstract: A fluid pump apparatus includes an elongated chamber within which a pair of pistons are movable. The chamber includes an intermediate inlet and outlets at the ends thereof. The pistons are formed of para-magnetic material and include passageways for providing fluid communication between the inlet and the outlets. An external magnetic drive system oscillates the pistons back and forth within the chamber, and includes two pairs of electrically conductive windings, wherein each pair surrounds the chamber at a position between the inlet and one of the outlets. The windings are energized in such a way that they cause the pistons to oscillate in unison with one another. Valves are provided for permitting fluid flow through the passageways in a direction from the inlet toward the outlets, and for permitting fluid flow from the chamber through the outlets. These valves also prevent fluid flow in the reverse direction.

Abstract: A method of measuring the distance at closest approach between the piston of a free piston compressor and the cylinder head. The method derives measurements of both the alternating and average components of piston position from direct measurements of the voltage and current applied to the linear permanent magnet motor that drives the piston, and thus eliminates any requirement for an additional position sensor located within the compressor.

Abstract: The inside-outside positional relationship between a field core of an electromagnet and an armature provided on a piston in an electromagnetic pump is reversed as compared with the prior art pump, that is, an annular armature is placed outside and a field core is placed inside the armature. The annular armature attached to the piston reciprocates in the axial direction thereof and the inside surface of the armature is opposed to the outside circumference of the field core of an electromagnet having formed thereon a plurality of outwardly and radially projecting magnetic poles, and being fixed to a part of a casing.

Abstract: An electromagnetically operated fixed displacement pump is sought, which can cope with diversification of electromagnetically operated fixed displacement pump products, and internationalization of their destination, readily permits cost reduction by mass production and permits efficient supply and control of products. A terminal portion electrically connected to the electromagnetic coil projects from the top of the pump body. A control unit with a control section for controlling the stroke number is removably mounted on the terminal unit. The pump body is supplied with current from lead pins of a power source connector provided on the control unit through the terminal portion. The control unit is prepared according to the specifications of various pump products. Various control units thus can be replaceably mounted on the terminal portion with the pump body as a common component. It is thus possible to provide pump products meeting various specifications.

Abstract: This invention relates to linear motor compressors which operate without the use of oil and a gas bearing while providing a flexible suspension for such a compressor. Such structures of this type, generally, provide a highly reliable oil-free compressor for use with cryogenic refrigeration equipment so as to attain unattended, continuous operation without maintenance over extended periods of time.

Abstract: A fluid pumping apparatus for producing fluid from a well through production tubing comprises an elongate hollow body to be disposed in a well bore and at least partially submerged in fluid to be produced from the well, the body including fluid inlet valve at its lower end for flow of fluid into the body, a plunger assembly disposed in the interior of the body for reciprocating movement relative thereto, sealing means cooperating with the plunger assembly to divide the body into isolated lower and upper chambers and to isolate the body from the production tubing, and fluid flow control valves operationally synchronized so that fluid is forced up the production tubing upon downstroke of the reciprocating plunger assembly in the body of the pumping apparatus. A method of pumping fluid utilizing the apparatus of the invention to produce fluid on the downstroke of the plunger assembly is also provided.

Abstract: The liquid fuel burning apparatus includes a fuel tank, a burning unit for burning the fuel, an electromagnetic pump for sucking the fuel from the tank, a feeding pipe for feeding the sucked fuel to the burning unit, and a control unit for controlling the electromagnetic pump. The electromagnetic pump has a plunger which is reciprocated by a plunger solenoid to suck the fuel in the fuel tank and discharge the sucked fuel therefrom in the associative motion of a suction and a discharge valves incorporated therein. The control unit opens the valves for a predetermined time when the fuel supply is stopped. Thus, fuel remained at an end of the feeding pipe is collected from so that the unburnt gas or strange smell which would be generated when the unnecessary liquid fuel is supplied to the burning means can be restricted.