Abstract: A linear actuator includes permanent magnet annuli arranged about an armature core for axial movement in a tubular stator upon energization of coils arranged in concentric association with the armature. The stator has portions extending radially inwards of the coils and towards one another beneath each coil, which define a spacing between the coil and the armature. The annuli have a substantially radially magnetized structure and the coils are configured for single phase power input. In one embodiment (FIG. 6), two pairs of spaced annuli are arranged on the core, wherein the axial length of the outermost annuli is half the axial length of the inner annuli.

Abstract: An electromagnetic inertial actuator includes a support base and a parallel arrangement of a first flexure part, a voice coil motor part, and a second flexure part. The parallel arrangement is cantilevered from the support base.

Abstract: A nano-scale compliant mechanism includes a coupler and a plurality of nanotubes disposed for nano-scale motion relative to a grounded component. The nanotubes are fastened at one end to the coupler and at the other end to ground, to guide motion of the coupler relative to the ground. Particular embodiments include a plurality of parallel carbon nanotubes. An exemplary embodiment exhibits first and second regions of mechanical behavior; a first region governed by bulk elastic deformation of the nanotubes and a second region governed by compliant, hinge-like bending of the buckled nanotubes.

Abstract: The present invention provides a power generator for generating electricity comprising a core having an interior chamber, the interior chamber having a top portion and a bottom portion. The core is filled with a volume of a gas. A frequency generator is provided for resonating the gas at a high frequency, and means for securing the frequency generator to the core are provided as well. In addition, a pair of electrical conductors is connected to the core to conduct the flow of electricity away from the core.

Abstract: Apparati and methods for generating electricity which comprise in one embodiment a pair of stationary magnets oriented so that their like poles are facing one another with a space between them, and having a stationary length of wire disposed in the space between said magnets of said pair and enabling or causing the passing of a piece of metal through said space sufficient to cause an electrical potential in the wire. In one embodiment, the length of wire comprises a coil of wire having any number of turns between about 10 and about 5000. In another embodiment, the length of wire comprises a plurality of serpentine sections or loops disposed along the length of a tube or other form inside of which the piece of metal is made to move.

Abstract: The drive system for a personal care appliance, such as a toothbrush, includes a first opposing pair of permanent magnet assemblies positioned longitudinally along the length of the internal surface of a cylindrical appliance housing, each first permanent magnet assembly having one portion with a north polarity and the other portion a south polarity, and a second pair of permanent magnet assemblies which are orthogonal to the first pair of permanent magnet assemblies, one second permanent magnet assembly having a plurality of abutting first parts along the length thereof, the parts alternating between a north polarity and a south polarity, the other second permanent magnet assembly having similar parts with reversed polarity. First and second armatures are mounted on, or a portion thereof forms, a spindle element which extends along the length of and outward from the cylindrical housing.

Abstract: An electromagnetic actuator is provided, including a bobbin made of a non-magnetic material including a hollow cylindrical portion and disk flanges; a coil formed between the disk flanges; a power supply which supplies a current to the coil; a movable member pivoted on the hollow cylindrical portion; and a stationary member made of a permanent magnet and fixed to a disk flange. The movable member is a magnetic material and includes a shaft portion and a rotating portion. The rotating portion is fixed to the shaft portion, lies on the disk flange, and extends in a radial direction of the shaft portion. When the power supply supplies the current to the coil in a predetermined direction, the rotating portion is magnetized to a predetermined polarity and rotates. The stationary member includes a stopper for stopping rotation of the movable member at a predetermined rotational position.

Abstract: The aim of the invention is to provide a robust, simple woodworking machine. To achieve this, the invention provides a machine comprising at least one linear direct drive, which contains a primary part (3, 3a, 3b, 4, 4a, 4b) with a first element (9, 10, 12, 14) for generating a first magnetic field and at least one additional element (17, 18, 20, 27, 28, 29, 30) for generating an additional magnetic field. The first element (9) for generating the first magnetic field is positioned, in particular, in such a way in relation to the additional element (17, 18, 20, 27, 28, 29, 30) for generating the additional magnetic field that the first magnetic field overlaps the additional magnetic field. The machine also comprises a secondary part (5, 6, 6a, 6b), which comprises magnetic return elements and is devoid of magnetic sources.

Abstract: Electromagnetic motor with a piston that moves linearly with respect to the stator in either direction. Embodiments include a piston internal or external the stator. The piston includes one or more magnetic flux producing elements in all embodiments, with some embodiments having a ferro-magnetic plate on either side of the flux producing element. Further, in all embodiments the stator includes three magnetic flux producing elements with either two coils with one or more magnets therebetween or with the two coils and a coil magnet substitute therebetween. All embodiments provide positive piston return to a center at rest position. In all embodiments the piston is centered with respect to the stator resulting from either magnetic interaction between the piston and stator magnets, or between the piston magnet and the stator magnet substitute coil.

Abstract: A method of retrofitting for electrical power generation an internal combustion engine (including a plurality of pistons connected to a common crankshaft) includes applying to at least one and optionally to each piston a power converter operable to convert mechanical energy of the piston to and from electrical energy.

Abstract: An electromechanical generator for converting mechanical vibrational energy into electrical energy, the electromechanical generator including a cantilever spring having a fixed end, a free end and a central portion therebetween, a mount for the cantilever spring to which the fixed end is fixed, a mass located at the free end of the cantilever spring, the mass including either a coil or at least one magnet defining a region of magnetic flux, wherein at least one of the fixed end and the free end of the cantilever spring is substantially stiffer than the central portion of the cantilever spring.

Abstract: In a linear motor, the stators and sliders are arranged to fill a predetermined relationship. In one configuration, two stators each include a plurality of stator blocks arranged in a moving direction of sliders so that projecting poles are maintained at predetermined intervals. Boundary surfaces are formed in adjacent stator blocks so as to be displaced relative to one another between the two opposite blocks by a distance Ld in the moving direction of the sliders. When a distance between end surface of the slider blocks is defined as L and the overall length of one stator block is defined as L0, the components are arranged such that Ld>L/3 and (L0?Ld)>L/3.

Abstract: Various embodiments of the present invention comprise linear-resonant vibration modules that can be incorporated in a wide variety of appliances, devices, and systems to provide vibrational forces. The vibrational forces are produced by linear oscillation of a weight or member, in turn produced by rapidly alternating the polarity of one or more driving electromagnets. Feedback control is used to maintain the vibrational frequency of linear-resonant vibration module at or near the resonant frequency for the linear-resonant vibration module. Linear-resonant vibration modules can be designed to produce vibrational amplitude/frequency combinations throughout a large region of amplitude/frequency space.

Abstract: The invention proposes an electric linear drive unit with an electric linear motor that is arranged in or on a basic housing. A sensor device arranged in or on the basic housing serves for determining at least one position of a driving element that is driven by the linear motor. Electric lines are routed from a coil system of the linear motor and from the sensor device to a common connecting point on the basic housing through at least one duct that extends within the basic housing, wherein said electric lines extend through the connecting point to a connector that is arranged at the connecting point and contains connecting means for producing a connection with external lines or cables. The connecting point is sealed by means of an insulating casting- or injection-molding compound at least in the region in which the lines extend from the connecting point.

Abstract: An electric generating system includes a vehicle having at least two mechanical components which are capable of reciprocating movements relative to each other; and an electric generator connected to the mechanical components and including a magnet unit and a conductor winding unit. The reciprocating movements include an interaction of the conductor winding unit and magnetic flux lines of the magnet unit to generate electricity. The electricity can be produced from vibration energy induced by shock.

Abstract: By reviewing a material of a forcer housing and an assembly structure of a coil member with respect to the forcer housing, a thrust force is increased, an optimum shape can be easily given to the forcer housing depending on a purpose of use, and a linear motor can be manufactured at low cost. The linear motor includes a magnet rod composed of a large number of magnetic poles arranged with predetermined pitches along an axial direction and a forcer having a through-hole into which the magnet rod is loosely inserted and reciprocatable relatively to the magnet rod according to an applied electric signal. The forcer is composed of a forcer housing in which the through-hole is defined and a coil member which is arranged on an inner peripheral surface of the through-hole of the forcer housing and to which the electric signal is applied. The forcer housing is formed by mold forming with an insulating nonmetal inorganic material.

Abstract: A vibratory linear actuator includes a stator with a magnetic pole surface, a movable member with a magnetic pole surface, an electromagnet arranged in one of the stator and the movable member, a permanent magnet arranged in the other of the stator and the movable member and a support unit for movably supporting the movable member so that the magnetic pole surface of the electromagnet can oppose the magnetic pole surface with a gap left therebetween. The actuator is designed to vibrate the movable member by supplying an electric current to the electromagnet. The support unit includes a fixed portion to be fixed to a housing for accommodating the actuator, and the stator is configured to be fixed to the support unit as the support unit is fixed to the housing.

Abstract: An electromagnetic generator comprising two magnets and a coil disposed therebetween, the two magnets being configured to define therebetween a region of magnetic flux in which the coil is disposed whereby relative movement between the coil and the magnets generates an electrical current in the coil, and a vibratable first mount for each of the magnets and a vibratable second mount for the coil whereby each of the at least two magnets and the coil are respectively vibratable about a respective central position.

Abstract: The motor includes an E-core stator assembly with a source of alternating current and an armature portion mounted to be responsive to the stator to oscillate back and forth through an arc portion of the personal care appliance and flexure elements are connected between the armature and the mounting member, the flexure elements crossing each other, wherein the crossing point defines a pivot point about which the armature rotates. A workpiece assembly, which includes a mounting arm, is configured so that a skin brush mounted on a free end of the mounting arm has an axis of rotation about the pivot point.

Abstract: An autonomous-power radio device including an electromagnetic energy transducer having a permanent magnet (1), a soft-magnetic element (9), an electrical coil (6), and stop points (8a-8d). The electrical coil surrounds a part of the magnetic circuit, wherein the permanent magnet (1) and said soft-magnetic element (9) are arranged to form a magnetic circuit with a first flux direction. At least one of the soft-magnetic element (9) and the permanent magnet (1) is mounted for rotary movement about an axis (4) with respect to the other. End points of the rotary movement are formed by the stop points (8a-8d).

Abstract: The present invention provides a linear motor 1 that can prevent a magnet member 2 from falling down when a power supply is turned off. A linear motor 1 includes a magnet member 2 composed of permanent magnets having alternately arranged respective N poles and S poles and a coil member 3 which surrounds a periphery of the magnet member 2 and trough which the magnet member 2 is movable in an axial direction relative to the coil member 3. A magnetic substance 3 is provided in the vicinity of one end of the coil member 3 to allow the magnet member 2 to exert a magnetic attractive force.

Abstract: Disclosed is a stator of reciprocating motor comprising: a stator including two lamination assemblies formed accordingly as a plurality of lamination sheets are stacked as a cylindrical shape or a circular are shape; and a mover inserted into an air gap between said two lamination assemblies and linearly reciprocating. In the stator, the lamination sheets constituting the lamination assembly are thicker at an outer circumference side of the lamination assembly than at an inner circumference said thereof. According to this, a path of a flux applied to the lamination assembly is maximized thus to minimize a resistance of the flux.

Abstract: The invention relates to a magnetic actuating device containing a reference element and an adjusting element which is movably disposed between first and second end positions with respect to the reference element. The reference and/or adjusting elements contain a magnetizable material. A drive coil is provided for generating a magnetic field that moves the adjusting element from the first to the second end position. A mechanical clamping device is provided for producing mechanical forces that move the adjusting element from the second to the first end position. A fixing device is provided with a permanent magnet for generating a holding force fixing the adjusting element in the second end position with respect to the reference element. The fixing device contains a fixing unit separated from the adjusting element and provided with the permanent magnet.

Abstract: A linear motor with an integrated guidance comprising a base plate comprising at least two side walls, and a travel plate guideably connected to the base plate in a linearly movable manner, wherein the travel plate comprises at least two rails and is connected to a plurality of rollers, wherein the plurality of rollers travel on the at least two rails.

Abstract: A displacement type generator including a magnet set and a coil set is provided. The magnet set includes a magnet with unidirectional magnetization and a first multi-polar magnetic structure, wherein the first multi-polar magnetic structure is disposed on the magnet. The coil set includes a magnetic center pole, a coil and a second multi-polar magnetic structure. The coil is wound on the magnetic center pole. The second multi-polar magnetic structure is disposed on the magnetic center pole and is adjacent to the first multi-polar magnetic structure. As a relative movement is generated between the magnet set and the coil set, the magnetic flux changes and causes the coil to output an induced voltage.

Abstract: A displacement device is provided with a linear motor which comprises a first part comprising magnetic strips and a second part comprising a coil block. The parts are connected via a linear guide. The second part is movable with respect to the first part in a conveying direction extending parallel to the guide. The displacement device further comprises an connected to said second part, which is located on a side of the first part remote from the second part. The displacement device can be used is a component placement device.

Abstract: At least one exemplary embodiment is directed to an alignment apparatus which includes a moving member, a structural object arranged on the moving member, and an electromagnetic actuator which moves the structural object relative to the moving member. The electromagnetic actuator includes a plurality of linear motor units, which apply forces in the horizontal direction and the vertical direction to the structural object. The plurality of linear motor units apply, to the structural object, forces in the rotation direction about each of two axes orthogonal to each other in the horizontal plane and the rotation direction about the axis in the vertical direction.

Abstract: An oscillatory device incorporating a limited angle torque motor capable of oscillating one or more end effector(s) is provided. The device may additionally incorporate an ultrasound transducer and/or a waveguide structure.

Abstract: A radiator for a linear or curved mobile motor for removing the thermal distortion of a mover and a transporting member of a linear or curved mobile motor, and a high-accuracy, high-reliability linear or curved mobile motor using it. The linear or curved mobile motor includes a field pole having a plurality of permanent magnets with different magnetic poles arranged alternately along a field yoke, and an armature arranged opposite to the field pole via a magnetic gap and formed by winding a single or a plurality of coils around a core. The field pole is used as a stator and the armature being used as a mover that is relatively moved along the longitudinal direction of the stator.

Abstract: An electromagnetic transmission device. A guide bar connects to a fixed base and includes magnetic-permeable material and a first central height plane. A coil connects to the fixed base. A support base movably fits on the guide bar. An annular magnetic member connects to the support base and is surrounded by the coil. A magnetization direction of the annular magnetic member is perpendicular to a moving direction of the support base and annular magnetic member. The annular magnetic member includes a second central height plane. The coil interacts with the annular magnetic member to generate a first force. When moving to separate the second central height plane from the first central height plane, the annular magnetic member interacts with the guide bar to generate a second force, driving the support base and annular magnetic member to move along a direction perpendicular to the magnetization direction of the annular magnetic member.

Abstract: A vibration actuator having a simple small-sized structure capable of obtaining vibration enough to sense without use of suspension or the like is provided. Amplitude of a moving part is restrained by a magnetic gap formed by cup-shaped yokes which are formed to interpose a magnet, and the moving part is vibrated without collision of the moving part with an inner wall of a fixed part. Therefore, magnetic force exerted between the moving part and the fixed part is allowed to function as a suspension. Therefore, it is possible to solve a problem, that is, reduction in the amplitude caused from the suspension. In addition, an air damper structure that air in upper and lower space of the moving part is used as a damper is provided, so that it is possible to obtain a wide frequency band.

Abstract: A specific condition for enhancing the power generation efficiency of an oscillation type electromagnetic power generator is disclosed. Solenoid coils constituting the oscillation type electromagnetic power generator are wound in directions opposite to each other with a predetermined coil gap therebetween. Adjacent magnets of a movable magnet are connected to each other via a spacer having a predetermined thickness in such a manner that poles with the same polarity are opposed to each other. A coil pitch which is the total dimension of the coil length of one solenoid coil and the coil gap and a magnet pitch which is the total dimension of the magnet length of one magnet of the movable magnet and the thickness of the spacer are almost equal to each other, and the coil length is shorter than the magnet length.

Abstract: An electrical energy generator that converts kinetic energy harvested from voluntary motor activity of a human or animal to electrical energy. The electrical energy generator includes a housing, a coil of electrically conductive material, a reciprocally movable electromagnetically active mass, springs connecting the mass to either the housing or to adjustment means engaged with said housing, and, optionally, means for constraining non-linear motion of the electromagnetically active mass, and/or means of mitigating motion retardation of the electromagnetically active mass within any existing housing atmosphere. The electrical energy generator may be associated with a carried item, such as a backpack.

Abstract: A long-proportional-stroke force motor which outputs force proportional to the exciting current. The motor has a magnetic circuit wherein a non-magnetic spacer is positioned axially between a magnetic guide and a magnetic sleeve. An armature moves within a central opening defined by the guide, the spacer and the sleeve. An end portion of the guide, adjacent to the spacer, has a sectional profile through a stepped surface facing radially outward and the corners of the steps define a curve which satisfies the following expressions: ? Y ? X > 0 , ? ? 2 ? Y ? X 2 > 0 , where X is a coordinate on an X-axis corresponding to a central axis of the guide; wherein the armature is moved in a direction along the X-axis by application of exciting current to a coil surrounding the guide, spacer and sleeve; and Y is a coordinate on an axis orthogonal to the X-axis.

Abstract: In a linear motor (1), the detent force is reduced by the height of the iron poles (522) being selected differently in the two outer regions of the coil set, preferably by a gradual reduction of the height of the iron poles (522) towards the ends of the stator (2). In combination with a slight inclination of the magnets, the detent forces are further minimized, with negligible losses of the propulsive force. The exact dimensioning of the iron poles (522) is dependent inter alia on the dimensioning of the coils (51) and other characteristics of the linear motor (1) as a whole, and can be found and optimized by simulations. Here, an optimum is sought between as great a reduction as possible of the detent force amplitude and as high a propulsive force as possible.

Abstract: The personal care appliance drive system includes a pair of linear actuators capable of operating both in an opposing phase mode or in a parallel (in-phase) mode. The system includes a motion converter assembly which converts the opposing phase action of the two linear actuators into a rotational action of an output drive shaft and converts in-phase action to a translation motion of the output shaft or to drive another function of the appliance, such as a pump. The motion converter, operating simultaneously in an opposing phase mode and in-phase modes, produces a complex motion of the workpiece.

Abstract: An system and apparatus for capturing electricity comprised of: a wheel and a fixed conducting rod, both in electrical contact with the wheel and at least one electrical component or system in which the wheel is rotatable about an axis. The wheel is comprised of: a rotatable hub; a rotatable conducting rod within the rotatable hub; at least one electricity generating device positioned on the hub and comprised of: a generally hollow housing having a distal end and a proximate end; a wire coil fixed within the housing and having an axial bore therethrough; a translatable magnet; and at least one wire in electrical contact with the wire coil and the rotatable hub; wherein as the wheel is rotated, the translatable magnet laterally translates back and forth within the housing and passing through the wire coil to generate the electric current.

Abstract: A linear drive device comprising at least one excitation winding for producing a variable magnetic field and is provided with an associated yoke body conducting a magnetic flux and an armature body which comprises a magnet carrier provided with at least two permanent magnet parts, preferably in the form of a plate, and to which an axial oscillation movement can be transferred by the magnetic field of the excitation winding. In order to avoid eddy currents in the magnet carrier, it is made of an electrically insulating material at least in the part thereof which penetrates into the magnetic field area defined by the pole surfaces of the yoke body and the excitation winding or which are arranged in said area. The magnet parts can be provided with ferromagnetic covers.

Abstract: A linear drive device includes an excitation winding producing a variable magnetic field and including an associated magnetic-flux-carrying yoke body having pole surfaces, and an armature body including a magnet carrier having at least two permanent magnet parts and an axial oscillation movement being transferable to the at least two permanent magnet parts by the variable magnetic field of the excitation winding. The magnet carrier includes an electrically insulating material at least partially extending into the magnetic field area defined by the pole surfaces of the yoke body and the excitation winding.

Abstract: Electric power is stored in a flywheel assembly, from a dc power buss, and supplied to the buss, through electronics associated with a motor/generator, its rotor integral with a flywheel supported by magnetic bearings. Upon operation, the flywheel assembly is released by mechanical backup bearings which then normally remain disengaged until shutdown as the flywheel assembly is levitated by the axial magnetic field. Enhancements developed herein smooth the flux density across discontinuities or segments present in permanent magnets due to presently limited capability for manufacture of large annular magnetic members. Herein, the introduction of a medium such as a steel cylindrical member to directly interface with the rotor as opposed to the segmented permanent magnet, greatly eradicates induced eddy current and heat on the rotor. In addition, exhibited is an annularly slotted rotor which allows for greater surface area for flux absorption.

Abstract: An auto focusing camera includes a lens unit (2) including a barrel (20) and a lens (22) received in the barrel, a permanent magnet (3) being fixedly mounted around the barrel of the lens unit and moving with the lens unit when the lens unit undergoes telescopic movement during operation, and a coil seat (6a, 6b) with a coil (5a, 5b) wound thereon arranged at a side of the permanent magnet. An interlocking device (642, 202) is formed on the barrel and the coil seat for guiding the telescopic movement of the lens unit.

Abstract: A vibration assembly includes a container, a vibration member containing a hollow portion with a bottom, at least two support members, a magnetic body, a coil having a spool axis, and a diaphragm that is attached to the container. Each of the support members has a flat and corrugated configuration. An end of the one of the support members is bonded to a portion of an edge portion of the hollow portion of the vibration member. The other end of the one of the support members is fixed to a portion of an upper edge of the container. An end of the other support member is bonded to the other portion of the edge portion of the hollow portion of the vibration member. The other end of the other support member is fixed to the other portion of the upper edge of the container.

Abstract: A repelling magnetic field engine. An illustrative embodiment of the engine includes a cylinder, a piston reciprocally mounted in the cylinder and emitting a static magnetic field, a magnet assembly provided in the cylinder and emitting a dynamic magnetic field having the same magnetic polarity as the static magnetic field and a crankshaft drivingly engaged by the piston.

Abstract: A moving coil type linear actuator system which can stably and linearly control a relatively large load despite using relatively low electric force applied to a coil unit, thus enhancing control accuracy and preventing energy loss.

Abstract: A reciprocating linear actuator in which a slide and a counter slide are arranged for linear movement within a hollow guide. The actuator has driving force generating means for generating a driving force between the slide and the counter slide and also has bearing structures formed individually between the guide and the slide and between the guide and the counter slide. If an external force acts on the slide, the external force is transmitted from the slide to the guide through the bearing structure between them.

Abstract: The present invention relates to the “Magnetic pistons engine”, hereafter called “Maps engine” or “RAT engine” or “engine” that works on the principle of magnetism. It can be used to perform various tasks and functions that involve application of force or displacement of objects. This method provides an environmental friendly, very high efficiency engine that can complement or replace any engines that use fossil fuel, bio-fuel, solar power, wind power, hydro power, electricity, stored energy, or other energy sources.

Abstract: A printed circuit board (PCB) coil linear actuator is disclosed. The actuator includes a coil assembly and a magnet assembly. The coil assembly includes a plurality of PCB coils electrically connected in series. The PCB coils arranged in a row and adjacent PCB coils are separated by a gap. Each PCB coil includes a low aspect ratio, multi-layer coil member disposed on a board member. The actuator assembly includes a plurality of magnet units arranged in a row, wherein adjacent magnet units are separated by a gap. When the actuator is assembled, the PCB coils arranged in alternating sequence with the magnet units. The PCB coil linear actuator is intended to replace traditional slotted bobbin voice coil actuators (VCAs) and is particularly useful in fast steering mirror (FSM) applications. The PCB coil linear actuator provides many advantages over a VCA of an equivalent motor constant, including improved performance, lower weight and a lower profile.

Abstract: A sensorless method and apparatus for detecting piston collisions in a free piston linear compressor motor. The waveform of the back EMF induced in the motor stator windings is analysed for slope discontinuities and other aberrations in a time window centred on the back EMF zero-crossings. Waveform slope artefacts are indicative of piston collisions and cause the motor power to be decremented in response.

Abstract: A stator fixing apparatus of a reciprocating compressor comprises a first frame on which a plurality of first core blocks, each comprising a plurality of laminated stator core sheets, are radially coupled, the plurality of first core blocks being coupled to one side surface of a bobbin body, and a second frame on which a plurality of second core blocks, each comprising a plurality of laminated stator core sheets, are radially coupled. The plurality of second core blocks are coupled to the other side surface of the bobbin body. A coupling portion is provided at each contact portion between the first core block and the second core block, for coupling the first and second core blocks. Thus, deformation of an initial shape of the stator or increase of a defect rate due to a molding material can be prevented, and heat and moisture can easily be discharged, so as to improve the efficiency and reliability of the reciprocating compressor.

Abstract: There are provided a linear motor and the linear compressor using the linear motor. The linear motor includes a bobbin, a coil wound in the bobbin, an outer core provided on the bobbin, an inner core provided to perform a linear reciprocating motion with a moving body, and a magnet provided on the inner core so that the inner core and the moving body perform a linear reciprocating motion. The magnet is configured to provide a gap between the magnet and an outer core and to be in close contact to the inner core.