Abstract: A two-stage piston pump has serially arranged pump chambers each having an input passage and a delivery passage. The first stage has a larger displacement than the second stage such that complete filling of the second stage is attained. The piston of the first stage is reciprocated through the cooperation of a spring and a selectively energizable solenoid coil. The piston of the second stage is secured to and reciprocable with the first stage piston. The cylinder for the second stage has an overflow passage disposed to ensure that all the fluid discharged from the first stage prior to the second stage piston closing the overflow passage passes through the second stage cylinder.

Abstract: A long lifetime Stirling cycle cryogenic cooler particularly adapted for space applications comprised of a compressor section (10) centrally aligned end to end with an expansion section (12) and respectively including a reciprocating compressor piston (14) and displacer (16) radially suspended in interconnecting cylindrical housings (18, 20) by active magnetic bearings (26, 28, 30, 32) and having adjacent reduced clearance regions (82, 84, 108) so as to be in non-contacting relationship therewith and wherein one or more of these regions operate as clearance seals. The piston (14) and displacer (16) are reciprocated in their housings (18, 20) by linear drive motors (48, 52) to vary the volume of respectively adjacent compression and expansion spaces (44, 46) which contain a gaseous working fluid and a thermal regenerator (95) to effect Stirling cycle cryogenic cooling.

Abstract: A reciprocating electromagnetic pump, particularly but not exclusively for non viscous fluids, adapted to considerably reduce hum and heat loss, at the same time decreasing the electrical input, wherein the trunk piston of magnetic material, subjected to the unidirectional electromagnetic force produced by an AC-fed coil enclosing said piston, consists of a set of coaxial overlapping liners instead of a single piece. The higher is the number of these overlapping liners and the more considerable is the effect, which may be further improved if they are covered with an insulating adhesive before assembly and the cylinder for the piston is also made of magnetic material instead of the conventional non magnetic material.

Abstract: A solenoid-operated pump for discharging fluid from a tank through a fluid discharge passage in a pump body has a directional control valve disposed in the fluid discharge passage. The directional control valve is normally urged to direct fluid flow through a fluid drainage passage branched from the fluid discharge passage and adapted for connection to the tank. The fluid drainage passage includes a restrictor which produces a fluid-pressure build-up in response to a change in viscosity of the fluid flowing therethrough, that is, when air is no longer contained in the fluid. The directional control valve is responsive to such pressure build-up to direct the fluid to flow through the fluid discharge passage.

Abstract: An electromagnetic plunger pump includes a plunger which is electromagnetically activated. Normally, the plunger is supported in a balanced condition by a pair of opposing springs. Further, the plunger is vertically pierced by a hole extending along an axial line in which the plunger reciprocates in the vertical direction, responsive to an application of an intermittent electromagnetic force. A valve body is loosely fitted into a rod inserted in the vertical hole, reaching a contact portion of a discharge plunger, which interlocks with the electromagnetic plunger. The discharge plunger is forced shut by a spring acting in the valve closing direction. The valve body engages a valve seat to close a discharge passage during a pump shut-down. The valve body is liberated from the valve seat to open the discharge passage during pump operation.

Abstract: A sensor utilizes the opposition of a fluid to physical displacement to provide information about the fluid itself, such as its quality as measured by its density or viscosity, or about the state of a fluid system which contains it, such as the fluid pressure existing at some point in the system. The sensor includes a fluid displacement device or element physically adapted to displace the fluid and repetitively urged into displacement by the application of a known impetus or urging force. The resulting motion of the element is then analyzed to obtain the information desired. The fluid displacement element may additionally perform a pumping function, or it may operate in a fluid stream externally powered. When employed as a pump, the sensor may provide information on the fluid pumped or on the state of the fluid system.

Abstract: A solenoid-actuated hydraulic fluid pump having a reciprocable armature operable by a magnetic circuit and with dashpot structure to limit movement of the armature beyond a predetermined position to avoid noise-creating contact with another part of the pump.

Abstract: A bottom hole well pump comprising a pump housing supported by a control cable for raising and lowering the housing within tubing in a well, a linear motor within the housing causing reciprocation of a plunger extending into a pumping chamber formed by the housing with inlet and outlet check valves for controlling flow of oil or other liquid into the pumping chamber and from the pumping chamber into the tubing above the pump housing. In one embodiment, Belleville-type springs are employed for storing energy as the plunger approaches its opposite limits of travel in order to initiate movement of the plunger in the opposite direction. In this embodiment, a single pumping chamber is formed above the linear motor with a single-valve block arranged above the pumping chamber and including inlet check valve means for controlling liquid flow into the pumping chamber and outlet check valve means for controlling liquid flow from the pumping chamber into the tubing interior above the pump housing.

Abstract: An electromagnetic fluid pump having a magnetic circuit responsive to a predetermined position of a reciprocating magnetically permeable piston is disclosed. The reciprocating piston closes the magnetic circuit at the end of its pumping stroke increasing the value of the signal produced by a hall effect switch. The increased value of the generated signal energizes a solenoid coil returning the piston to a cocked position against the force of a resilient member which urges the piston forward on its pumping stroke.

Abstract: A solenoid operated metering pump for displacement of exact amounts of fluid pumped by reciprocation of pumping piston incorporating integral check valve has an elongated valve housing with solenoid operator serving as pump actuating means attached to one housing end while the other housing end is adaptable to serve as the fluid pumping means including an appropriate housing bore passing therethrough and adaptable to receive a differential diameter piston assembly slidably movable therein to reciprocate when solenoid operator becomes electrically cycled inducing fluid flow through appropriate pump chamber created therein between piston and housing bore portion provided with fluid supply port having a detachable check valve with a simple floater for a directional flow control therethrough, means of piston actuation from a first position checking flow and discharge of the fluid delivered to the pump chamber to a second position discharging exact fluid quantity per each stroke of pump reciprocation, and means of

Abstract: An apparatus and method having a first unit for creating mechanical movement with a certain frequency ofmovement. A second unit is operatively associated with the first unit for producing a pulsing electrical signal that has a pulse rate substantially proportional to the frequency of movement. A third unit is operatively associated with the second unit for producing a pneumatic signal that is substantially proportional to the pulse rate of the pulsing electrical signal.

Abstract: A fuel pumping apparatus comprises a housing which defines a boss portion. The boss is hollow and accommodates a pump barrel which is retained in position by means of a sleeve engaging a flange on the barrel. The sleeve is trapped between the flange of the barrel and a flange on a nozzle assembly and the latter is retained by a cap nut which is in screw thread engagement with the boss portion.

Abstract: A solenoid-actuated fluid pump having reciprocable armature operable by a magnetic circuit and with structure in the flux path at the upper and lower air gaps to substantially change the reluctance across the air gaps as the armature moves beyond a predetermined location. The armature has slots for passage of fluid therethrough and which have a C-shaped cross-section to minimize the air gaps.

Abstract: In an electromagnetic pump wherein a sleeve containing a reciprocating pump is clamped between inlet and outlet fixtures, a cylindrical rubber ring is mounted about the sleeve and compressed by the inlet and outlet fixtures to come into intimate contact against the sleeve thus forming a seal.

Abstract: A U shaped yoke member and a U shaped housing member are combined to define a closed space. A sleeve containing a plunger, an exciting coil wound about the sleeve, an oscillator for passing pulsating current through the exciting coil, a return spring, an inlet valve, an outlet valve, are contained in the space. The opposite ends of the sleeve extend through openings of a pair of spaced parallel legs of the yoke and are secured to the legs by inlet and outlet fixtures connected to the openings.

Abstract: In an electromagnetic pump wherein a plunger is reciprocated in a cylinder by an exciting coil energized by interrupted current from an oscillator, an insulating layer is coated on the outer surface of the coil and a space between the coil and a cover is filled with polyurethane foam.

Abstract: A fuel system for supplying fuel to an engine includes a nozzle positioned to direct fuel into a combustion chamber and an electromagnetically operable pump for supplying fuel to the nozzle. A first electronic means supplies power to a winding of the pump to cause delivery of fuel and holds the pumping piston of the pump until it is required to fill the pumping chamber of the pump. A second electronic means partly energizes the winding or another winding when the required amount of fuel has flowed into the pumping chamber, to hold the piston against movement.

Abstract: An electromagnetic pump particularly adapted for use with oil burners is disclosed. The pump embodies an armature that is reciprocated by a magnetic field produced by an electromagnetic coil. The armature drives the piston of a piston pump that is adapted to pump a liquid at low volume and high pressure. The pump also embodies a diaphragm disposed in a chamber having an inlet portion on one side of the diaphragm and an outlet portion on the other. The inlet portion of the chamber is connected to a liquid supply line leading to the pump and the outlet portion is connected to the discharge of the piston pump and also to a valve-controlled vent leading to atmosphere. The diaphragm is moved in one direction only by the armature and in the opposite direction by a spring. When there is air in the liquid supply line, the vent valve is opened and the diaphragm rapidly pumps air to the atmosphere. When liquid is discharged from the vent, the valve is closed.

Abstract: In an electromagnetically-operated fixed displacement pump, a lubricating oil storage tank and a communicating hole with one end opening upon the bottom of the tank are formed in a pump body, the other end of the hole in the pump body communicating with one end of another communicating hole extending through a movable armature in the axial direction thereof, the other end of the communicating hole in the armature opening into an electromagnetic gap between a fixed armature and the movable armature.

Abstract: An electromagnetic plunger pump of the reciprocating type including a vent valve means which allows only air bubbles in the pump to pass therethrough. This vent valve means is provided in a pressure adjusting plunger fitted in a pressure adjusting cylinder for reciprocating motion. The vent valve means comprises a vent valve rod which is fitted in a through-hole of the pressure adjusting plunger so as to form a passage about the vent valve rod, and a vent valve body which is normally energized by a spring in the direction away from a vent valve seat at a forward end of the pressure adjusting plunger to provide a clearance between the vent valve body and the vent valve seat. This clearance is such that it allows the air bubbles to pass therethrough, while it does not allow a liquid under pressure having a viscosity to pass therethrough with the result that the vent valve means is closed by such liquid under pressure.

Abstract: In the construction of an electro-magnetic fluid pump such as an air pump in which a piston assembly carrying an armature is driven for reciprocal axial movement due to operational combination of magnetic attraction generated by a stator core and mechanical spring repulsion for cyclic discharge of the fluid out of its piston chamber, the piston assembly is postively supported on both axial sides of the stator core and a pneumatic spring is incorporated within the piston assembly. Biased movement of the piston assembly and bias in the magnetic attraction are both successfully prevented in order to minimize undesirable abrasion of the piston assembly and its related parts.

Abstract: An electromagnetic pump having a pressure adjusting function that holds discharge pressure constant; a decompression valve for throttling an outflow is provided in the path of the discharge side and this decompression valve is displaced by a pressure receiving plunger to which the pressure of the discharge side is applied. The pressure receiving plunger is slidably provided in a cylinder, and a pressure adjusting spring facing the pressure receiving plunger of the cylinder is disposed in the chamber located on the opposite side of the decompression valve; a return path communicating with a suction side of the electromagnetic pump is formed in the chamber. The pressure is adjusted by the decompression valve, and the fluid leaking into the chamber located on the opposite side of the decompression chamber of the cylinder is returned to the suction side by means of the return path.

Abstract: An electromagnetic pump characterized in that two independent coils disposed adjacent each other and via a common magnetic path are used for actuating a plunger and a valve, respectively, thereby preventing the generation of noises and abrasion during the operation of the pump. This also attains the quick return of the valve to its home position at the time when the pump stops, thus resulting in the complete stoppage of oil leak.

Abstract: A pump for moving fluid, as blood, having a cylindrical body defining a chamber. A piston movably located in the chamber carries a one-way valve movable to an open position to allow fluid to flow into the chamber and movable to a closed position to pump fluid from the chamber. One or more solenoids operate to reciprocate the piston in the chamber to pump fluid from the chamber. A one-way valve in an inlet passage to the chamber functions to allow the flow of fluid into the chamber and restrict reverse flow of the fluid out of the chamber through the inlet passage.

Abstract: A solenoid operated metering pump for displacement of exact amounts of fluid pumped by reciprocation of pumping piston incorporating integral check valve has an elongated valve housing with solenoid operator serving as pump actuating means attached to one housing end while the other housing end is adaptable to serve as the fluid pumping means including an appropriate housing bore passing therethrough and adaptable to receive a differential diameter piston assembly slidably movable therein to reciprocate when solenoid operator becomes electrically cycled inducing fluid flow through appropriate pump chamber created therein between piston and housing bore portion provided with fluid supply port having a detachable check valve with a simple floater for a directional flow control therethrough, means of piston actuation from a first position checking flow and discharge of the fluid delivered to the pump chamber to a second position discharging exact fluid quantity per each stroke of pump reciprocation, and means of

Abstract: A moving-iron, linear-motor compressor suitable for use in a refrigerant system, wherein a conical armature reciprocates in a complementary air-gap under the influence of an electromagnetic circuit and a pair of linear (constant rate) complementary return springs connected to the armature between the compressor piston and an outboard bearing. The armature rod is made of magnetically permeable material. The electromagnetic circuit includes a pair of abutting convoluted loops of spirally wound magnetic strip material with a conical air-gap fabricated in the area of abutment. The motor has a layered construction which cooperates with the conical armature and air-gap such that the motor is self-aligning at the assembly stage.

Abstract: A high pressure electromagnetic reciprocating fluid pump is disclosed herein. The pump has a pair of telescoping cylinders axially disposed inside a generally cylindrical cavity of a pump housing. Unidirectional valves disposed at the opposing ends of the telescoping cylinders cause a unidirectional fluid flow through the pump as the telescoping cylinders are reciprocated relative to each other by a solenoid driven armature.

Abstract: An electromagnetic pump is disclosed in which a pair of check valves and a pressure-regulating mechanism are inserted in series in a fluid passage extending from a suction inlet to a discharge outlet and a pressure chamber operatively connected with a plunger is provided between the check valves. When a solenoid coil surrounding the plunger is supplied with an intermittent electric current, the plunger moves to and fro, thereby the pressure in the pressure chamber being varied to have the check valves given rise to pumping action. The pressure-regulating mechanism function to control the pressure of fluid discharged from the outlet, thereby absorbing the pulsation generated by the reciprocal pumping action of the plunger.

Abstract: A permanent magnet translational motor includes a double-ended cylindrical outer shell having a hollow interior, a solid cylindrical core in the hollow interior coaxially aligned with the longitudinal axis of the shell, and permanent magnet segments secured to the interior surface of the shell and surrounding the core. The permanent magnets develop a radial magnetic field across the air gap between the magnets and the core. A moving drive coil mounted on the core slides longitudinally back and forth in the magnetic field in response to changes in electric current passing through the coil. Opposed mounting brackets on the moving drive coil extend outwardly through longitudinally extending slotted openings in opposite sides of the shell for connection to a respirator piston. The drive coil is driven back and forth in response to an adjustable D.C. voltage waveform to control the pressure build up in the patient's lungs with respect to time during each inspiratory cycle of the respirator.

Abstract: A micropump capable of delivering very small, predetermined quantities of liquid, e.g. 0.1-100 microliters per stroke, is provided. The pump has a flexible, resilient diaphragm which operates as a movable resilient wall of a pumping chamber, under electromagnetic actuation of a plunger, to cause the pumping action. Other locations of the same resilient diaphragm, in co-operation with curved surfaces on the body structure, act as valves for the inlet and outlet conduits of the pump. The overall size of the pump need be no greater than about 4 cubic cm. Many of the liquid flow conduits therein are formed by co-operating channels or grooves cut in individual co-operating parts of the pump body. The pump may be surgically implanted into a patient's body, to deliver to the desired body location a very small, measured amount of pharmaceutical from an internal or external reservoir thereof, as and when desired.

Abstract: An electromagnetic plunger pump capable of keeping its delivery pressure substantially constant when the value of a voltage applied thereto remains in the range of values within the tolerance limits of variations. In this pump, spring constants of a restoring spring and an auxiliary spring are selected and the positions of an electromagnetic coil, an electromagnetic plunger and an annular magnetic pole are fixed such that there exists a relationship 0.1<la/lb<1 between the distance lb between the magnetically neutral point of the electromagnetic coil and the magnetically neutral point of the electromagnetic plunger and the distance la between the upper end of the annular magnetic pole arranged below one end of the electromagnetic plunger and the lower end of the electromagnetic plunger. By this arrangement, it is possible to maintain the delivery pressure of the electromagnetic plunger pump in a stable range in spite of a variation in the value of the voltage applied thereto.

Abstract: A constant-volume increment pipetting arrangement for use particularly in connection with analysis of minute specimen volumes of biological fluids. The arrangement, which is designed to have a very low inertia factor, comprises a pumping unit having a pair of two-port valves with a duct running between a port from each valve, wherein at least a portion of the duct wall is movable to provide a variable volume pipetting chamber. The second port of one valve serves as the intake port for the fluid to be pipetted and the remaining port of the other valve serves as the delivery port. Three reciprocating drive elements are provided, connected one each to the valves and to the movable portion of the duct wall. Associated with the drive elements is a sequential control means, wherein the control means portion for the drive element connected to the moving portion of the duct wall constitutes an electromagnet arrangement energizable by a periodic supply.

Abstract: A solid state switching circuit for an electromagnetic pump is disclosed herein. The circuit comprises a Darlington amplifier controlling the current flow through the pump's solenoid in response to the state of a piston position sensitive electrical switch, a Zener diode and capacitance in the base circuit of the Darlington amplifier in parallel with the electrical switch and an inductive clamp circuit in parallel with the pump's solenoid coil.

Abstract: A plurality of aligned magnets are movable with respect to each other and their polarities are changed to cause changing of the distances between adjacent magnets by opening and closing of air gaps therebetween. Driven magnets travel a distance which is greater than the air gap between any two adjacent magnets.

Abstract: A fuel injection pump comprises a housing a pump assembly mounted within the housing and an annular armature slidable within a bore defined in the housing. The armature is connected to a moving part of the pump assembly and located in the annular space between the pump assembly and the armature is an annular field assembly including a member which is supported by an end closure for the housing. The field assembly carries a winding which when energized effects movement of the armature and movement of the moving part of the pump assembly thereby to displace fuel through an outlet.

Abstract: The invention relates to a refrigeration type motor compressor assembly in which an integrated motor compressor unit is resiliently mounted in a sealed casing. A skeleton-like frame facilitates integrating the motor and compressor with a minimum amount of structural material. This frame includes a shaft bearing member and a cylinder member for the compressor function, these two members being joined by a beam member which is attached to the bearing member and extends to the cylinder member. The beam member has support posts depending therefrom which rest on the upper surface of the stator laminations.

Abstract: A reciprocating pump having a piston completely enclosed by and moving within a cylinder. The pumping action is provided by the interaction between a magnetic component embedded in the piston and an external varying magnetic field produced by a permanent magnet, solenoid, etc. The necessary back-and-forth motion is produced by momentarily offsetting the gravitational force by the spatial driving or time variation of the magnetic field and a suitable combination of valves is provided to control the fluid flow through the cylinder.

Abstract: A portable fluid transfer pump is disclosed herein. The pump comprises a small electromagnetically activated fluid pump embodying a highly reliable blocking oscillator cyclically activating a solenoid coil in the fluid pump, and an electrical power cord assembly including an electrical connector adapted to be received in a convenient source of electrical power. In the preferred embodiment, the electrical connector is a male connector adapted to be received in the cigarette lighter receptacle of a vehicle such as an automobile, recreational vehicle, truck, or boat.

Abstract: In an electromagnetic fluid operating apparatus such as an air compressor in which a piston with an armature axially reciprocates along a path substantially at a right angle to the magnetic flux generated by a stator core due to alternate operation by electromagnetic attraction and mechanical repulsion, exact collimations are automatically established between the armature and the stator core and between the piston and a cylinder for the piston when they are assembled together, thereby minimizing biased frictional abrasion of coacting sliding surfaces. Provision of an internal air reservoir at the air outlet terminal effectively reduces pulsation of air supplied by the apparatus.

Abstract: Disclosed herein is an on-demand fluid pump having a solenoid actuated reciprocating piston. The pump's electrical circuit comprises an oscillator generating at predetermined intervals short duty cycle sample signals which are applied to the solenoid. The reciprocating piston is nonresponsive to the applied sample signals, however, the sample signals induce a signal in a position sensor. The value of the signal induced in the position sensor is a function of the piston's position. A detector circuit generates a signal switching a bi-stable electronic switch to a SET state in response to an induced signal having a value indicative of the piston being at the end of its spring actuated pump stroke. The bi-stable switch in the SET state activates the solenoid to retract the piston against the force of the spring. The next sequential sample signal resets the bi-stable switch to its RESET state deactivating the solenoid.

Abstract: A hybrid blocking oscillator for an electromagnetic fuel pump is disclosed herein. The blocking oscillator embodies a temperature regulated bias control and two current dissipators for controlled dissipation of the currents induced in the solenoid and detection coils when the oscillator is in a blocked state. The disclosed hybrid circuit is capable of 5,000 hours of operation with a 99 percent reliability.

Abstract: An in-line pump construction for mounting in a fuel tank or fuel line having line connections at each end of a tubular construction, valves mounted within the tube and a filter retained by a line connector nipple at the inlet end adjacent a valve module, there being a remote control module positionable at a distance from the pump for easy access and replacement.

Abstract: In a closed-type compressor with an electromagnetic reciprocating drive, reliable and stable collimation of the electromagnetic driving part with the compressive pumping part is easily established by a snug engagement of fitting seats provided in the coupling plane of the two parts and lubrication of the piston and its related part is effected by a built-in type lubrication mechanism utilizing the flow of the gas returning from the given circulation system with simplified construction as well as in the case of compressors with rotary drive, the compressor being preferably used for cooling systems.

Abstract: An electrical vibration type compressor comprising a drive coil vibratably supported in a mechanical vibration system, a piston driven by the drive coil, at least one main semiconductor element with a control electrode which performs the switching control of a drive current to the drive coil, and a detecting means consisting of at least one detecting semiconductor element with a control electrode detecting the vibration of the drive coil to control the conduction and cutoff of the main semiconductor element with a control electrode and at least one timeconstant circuit; whereby the feedback transformer which has so far been used in a device of this type to supply a feedback current to the main semiconductor element with a control electrode is eliminated, and the switching operation is properly performed at the top and bottom dead centers of the piston.

Abstract: An electric motor driven compressor includes a reciprocating free-stroke armature driving a compressor piston in a cylinder. A cylinder head closes the cylinder to form a compression chamber into which opens an intake passage and an output passage selectively closed by valves. The output passage provides an opening into the compression chamber through the cylinder wall at a selected distance from the cylinder head to provide an energy absorbing chamber filled with gas when the piston closes the opening of the output passage during its compression stroke. The energy absorbing gas cushion in the chamber prevents impacts between the piston and cylinder head under varying operating conditions.

Abstract: An electromagnetic pump of the reciprocating type comprising a relief valve mechanism adapted to minimize the magnitude of pulsations of the fluid delivered by the pump and at the same time to act as a pressure accumulator. The relief valve mechanism comprises a pressure adjusting cylinder maintained in communication with the outlet side of the pump, a spring-loaded balancing plunger slidably mounted in the pressure adjusting cylinder, and a pressure adjusting screw adjustably mounted in the mechanism for regulating the biasing force of the spring so as to adjust the pressure applied by the spring to the balancing plunger to any level as desired.

Abstract: An electromagnetic pumping device for liquids particularly for feeding liquid fuel in combustion devices, comprises a housing having a pumping chamber with an inlet to the pumping chamber and a discharge from the pumping chamber and with a pumping diaphragm in the chamber having a magnetic armature with a piston rod portion which is actuated by a power circuit having a photoelectric switch therein which is turned on and off by the movement of an aperture in the rod portion of the switch past the photoelectric cell so that the armature and the pumping diaphragm are moved in accordance therewith to pump the liquid.

Abstract: An electromagnetic pump comprising an electromagnetic coil, magnetic paths constituting a yoke arranged in the electromagnetic coil, an electromagnetic plunger reciprocatorily mounted in the electromagnetic coil, and a main body including a suction port, a discharge port and suction and discharge valve means and connected to the electromagnetic coil. At least one of the magnetic paths has a reduced cross-sectional area portion at one end portion thereof disposed on the longitudinal axis of the electromagnetic coil and is formed with a magnetic gap between the reduced cross-sectional area portion and the end portion of the electromagnetic plunger. A movable iron member of the cylindrical shape is arranged in the magnetic gap in which the lines of magnetic force are concentrated in passing through the magnetic path. The movable iron member is moved upwardly by the electromagnetic force to facilitate further concentration of the lines of magnetic force therein.

Abstract: A moving-iron, linear-motor compressor suitable for use in a refrigerant system, wherein a conical armature reciprocates in a complementary air-gap under the influence of an electromagnetic circuit and a pair of linear (constant rate) complementary return springs connected to the armature between the compressor piston and an outboard bearing. The armature rod is made of magnetically permeable material. The electromagnetic circuit includes a pair of abutting convoluted loops of spirally wound magnetic strip material with a conical air-gap fabricated in the area of abutment. The motor has a layered construction which cooperates with the conical armature and air-gap such that the motor is self-aligning at the assembly stage.

Abstract: A linearly reciprocating fan for cooling a linear motor which drives the fan is disclosed as including a fan blade attached to the linear motor and means for guiding the air flow caused by the reciprocating blade across the linear motor to cool the motor.