Abstract: Disclosed herein is an outer stator of a motor mounted in a linear compressor for compressing a coolant gas. The outer stator comprises a coil assembly having a coil wound on a bobbin with flange parts formed at both sides thereof, and a plurality of core blocks disposed such that the coil assembly is surrounded by the core blocks. The flange parts of the bobbin are provided with bobbin pressing means, i.e., protrusions so that not only the core blocks but also the bobbin is pressed by means of a cylinder block and a back cover mounted in the linear compressor when the outer stator is assembled in the linear compressor, whereby the core blocks and the coil assembly of the outer stator are assembled in the linear compressor while the core blocks and the coil assembly of the outer stator are integrally attached to each other. Consequently, relative movement between the coil assembly and the core blocks is effectively prevented when the linear compressor is operated.

Abstract: A linear motor includes a secondary part (1) having several permanent magnets (4) disposed behind one another with alternating orientation of the polarity, or excitation windings. These permanent magnets (4) or excitation windings are wound helically around a rotation axis. Furthermore, there is provided a primary part (2) having a current-carrying winding disposed in parallel relationship to the permanent magnets (4) or excitation windings and arranged about the rotation axis such that a magnetic traveling field travels helically about the rotation axis.

Abstract: A linear motor includes tubular outer yoke (4), tubular inner yoke (3) disposed in outer yoke (4), coil (2) provided to inner yoke (3), permanent magnet (5a, 5b) vibrating following a magnetic flux produced by coil (2), and vibrator (6) made of magnetic material and supporting permanent magnets (5a, 5b). Magnetic loop produced by outer yoke (4) and inner yoke (3) travels through vibrator (6) free from interference by vibrator (6) because vibrator (6) is made of magnetic material. As a result, the linear motor vibrates efficiently.

Abstract: A solenoid for use in a valve such as an exhaust gas recirculation valve for a motor vehicle. The solenoid includes a housing having a coil for generating a first magnetic field. An armature is slidably mounted in the housing. The solenoid further includes a permanent magnet having a second magnetic field, wherein the magnet is located adjacent the armature. In addition, a stator is affixed in the housing for cooperation with the armature and the magnet to form a third magnetic field.

Abstract: A solenoid having increased axial force and low static friction on the armature is disclosed and provides an improved solenoid-driven hydraulic valve actuator. The solenoid includes a coil member, a pole piece having an inside surface with recessed and non-recessed portions to form an inner recess in the pole piece, an armature inside the pole piece, and a bearing held in the recess between the pole piece and armature, the bearing having an inner surface extending inwardly just beyond the inside surface of the pole piece non-recessed portion.

Abstract: A stator for a reciprocating motor comprises a bobbin made of an insulating material in which a winding coil is located; a terminal unit forming a single body with the bobbin and connecting the winding coil electrically with an outer power source; and a core unit stacked radially along with the bobbin started from one side of the terminal unit. Therefore, the winding coil and the bobbin can be coupled in simple way, and the core unit can be stacked simply and precisely, so the mass productivity of the motor is able to be increased. Also, the size of the core unit is able to be managed simply and precisely, and then, the contact and impact with other components constructing the motor is prevented, whereby the reliability of the motor can be improved.

Abstract: The invention relates to a switchgear, especially for actuating valves, comprising a housing (18) and a coil body (10) disposed therein in which a switch element is guided and which is provided with a winding (14) of a conductor (16) that is connected to a plug connector (22) via contact elements (20). At least some sections of the housing (18) and of the plug connector (22) are enclosed by a plastic compound (24), and sealing devices (40) seal off the interior (42) of the switchgear from the surroundings (44). At least one of the sealing devices (40) is configured as a sealing web (48), said sealing web (48) consisting of a meltable material. The sealing web (48) is disposed on the bottom face (50) of a plug plate (26) of the plug connector (22) which faces the housing (18).

Abstract: An electrical machine with at least a machine unit. This machine unit includes a stator, which includes a plurality of magnetic flux conductors, an electric conductor forming a winding extending in a substantially closed winding path through each magnetic flux conductor, and a least one first movable element, which includes a number of permanent magnet elements and which is movable in a reciprocating movement in relation to the stator along a first movement path in a space having a finite length and formed by at least some of the magnetic flux conductors. The winding path includes a first current carrying portion, which extends substantially in parallel with the first movement path. Each magnetic flux conductor is arranged to form, together with one of the permanent magnetic elements, a closed magnetic flux circuit extending around the current carrying portion.

Abstract: A linear actuator includes a moving part which has a facing surface and which is provided such that the facing surface of the moving part faces a facing surface of a stator. The moving part is lonearly movable. A permanent magnet is provided in one of the stator or the moving part and has a magnet surface facing the facing surface of another of the stator or the moving part. A cross-sectional area of the permanent magnet along a first plane substantially in parallel with the facing surface of the one of the stator or the moving part reduces toward the magnet surface.

Abstract: A solenoid valve achieves high reliability and small size with fine tolerance. The solenoid valve having a valve housing, an electromagnet composed of a coil, a yoke and a clapper armature having at least a first valve seat, and a sealing element which can be actuated by the clapper armature and which co-operates with the first valve seat. The yoke has yoke pins and the clapper armature is magnetically and pivotally connecting with one of the yoke pins at the end thereof that is remote from the sealing element. The clapper armature is guided through the coil.

Abstract: Apparatus for commutating turns of a stator coil for a helical coil launcher. An annular brush assembly includes an annular support and a plurality of electrical contacts disposed circumferentially about the annular support for contacting the stator coil. A projectile for a helical coil launcher is also disclosed having an armature coil and a body assembly containing at least one annular brush assembly for contacting a stator coil that is slidably engaged with the projectile.

Abstract: A transport system includes at least one product carrier which is adapted to be moved along a slide way by means of a linear motor drive unit comprising a primary part and a secondary part. In order to improve the transport system in such a way that basically any number of product carriers can be moved along the slide way independently of one another and can be used in a versatile manner for transporting different types of products or workpieces, the product carrier is provided with a substantially flat base plate for transporting objects, the base plate having associated therewith the primary part, and the slide way having associated therewith the secondary part.

Abstract: The present invention provides a linear motor, which can improve motor efficiency and which can be manufactured by a simplified procedure. The linear motor of the present invention includes a movable unit of cylindrical shape and having the central axis at the intersection of the X-axis and the Y-axis. An inner yoke is arranged on an inner side of the movable unit with a given spacing in the radial direction of the movable unit and is formed by laminating a multiple of thin plates each in approximately rectangular in shape and having strong magnetic permeability arranged in the direction of the X-axis. An outer yoke is arranged on the outer side of the movable unit with a given spacing in a radial direction of the movable unit and is formed by laminating a multiple of thin plates, each approximately rectangularly shaped and arranged in the same direction as the thin plates of the inner yoke. A pair of permanent magnets are magnetized in a direction from the inner yoke to the outer yoke.

Abstract: A linear motor includes tubular outer yoke (4), tubular inner yoke (3) disposed in outer yoke (4), coil (2) provided to inner yoke (3), permanent magnet (5a, 5b) vibrating following a magnetic flux produced by coil (2), and vibrator (6) made of magnetic material and supporting permanent magnets (5a, 5b). Magnetic loop produced by outer yoke (4) and inner yoke (3) travels through vibrator (6) free from interference by vibrator (6) because vibrator (6) is made of magnetic material. As a result, the linear motor vibrates efficiently.

Abstract: An optical switch actuator moving an optical element into or out of an optical pathway. The optical element is coupled to a movable shuttle and driven by a motor between two rest positions. The motor includes two stationary coils and a magnet attached to the shuttle. The shuttle is magnetically latched in the rest positions. The optical element's position at the extended rest position is controlled with a stop that contacts the shuttle to provide accuracy and precision about multiple axes. The material used to construct the actuator's components aids in repeatedly positioning the optical element with precision.

Abstract: An electrical generator has a plurality of mutually spaced magnets that move together relative to at least one coil to generate an electrical signal in the coils. Equal numbers of magnets and coils, with equal lengths and spacings between them, are preferably employed. Significant enhancements in power output are achieved by orienting successive magnets in magnetic opposition to each other, so that the magnetic fields from successive magnets along the axis of movement substantially cancel each other at locations between the magnets.

Abstract: A solenoid for use in a valve such as an exhaust gas recirculation valve for a motor vehicle. The solenoid includes a housing having a coil for generating a first magnetic field. An armature is slidably mounted in the housing. The solenoid further includes a permanent magnet having a second magnetic field, wherein the magnet is located adjacent the armature. In addition, a stator is affixed in the housing for cooperation with the armature and the magnet to form a third magnetic field.

Abstract: A compact portable transport unit for shipping hyperpolarized noble gases and shielding same from electromagnetic interference and/or external magnetic fields includes a means for shifting the resonance frequency of the hyperpolarized gas outside the bandwidth of typical frequencies associated with prevalent time-dependent fields produced by electrical sources. Preferably the transport unit includes a magnetic holding field which is generated from a solenoid in the transport unit. The solenoid includes a plurality of coil segments and is sized and configured to receive the gas chamber of a container. The gas container is configured with a valve, a spherical body, and an extending capillary stem between the valve and the body. The gas container or hyperpolarized product container can also be formed as a resilient bag.

Abstract: A pneumatically driven electric power generator includes a cylinder having one end connected to an air supply passage for receiving pressurized air and a piston having an associated magnetic moment. A portion of the piston is free to move into and out of the open end of the cylinder. An O-ring prevents airflow between the piston and the cylinder when a portion of the piston is located within the cylinder. A spring forces the piston from a position outside of the cylinder to a position inside the cylinder, so that the piston oscillates, moving into and out of the cylinder, driven by air supplied through the air supply passage. One or more electric coils are placed to enclose changing magnetic flux caused by the magnetic moment associated with the oscillating piston whereby an emf is generated in the coil(s) so that an external circuit connected to the coil(s) to complete a circuit through the coil(s) may receive electric power from the coil(s).

Abstract: A linear motor includes a stator including a stator core for forming plural magnetic poles and a magnetic wire mounted on the stator core, and a mover provided at the interior of the stator and including a mover core and a magnet mounted on the outer side of the mover core. The linear motor has the magnet have a reduced mass, thus having a small size, a low overall cost, and a high operating efficiency.

Abstract: An array (10) contains a rotary electromagnetic motor (11) and/or a linear electromagnetic motor (12) that is (are) attached to a tool-carrying sleeve (19) of a machine tool that carries out high-speed working in order to draw off shavings, in which magnets (13, 14i) of the motor(s) are integral with the tool-carrying sleeve (19) itself. In the array (10) magnets (13, 14i) are made integral with the tool-carrying sleeve (19) by a hollow tube (15) that is attached coaxially to the tube on an inside wall (15g) where the magnets are attached coaxially. The array (10) also contains a hollow shaft (16) that is fixed in place while the array (10) is in operation and is inserted coaxially into the hollow tube (15). A number of stator induction coils (17) that interact with the magnets (13, 14i) are arranged on an outer surface of the hollow shaft, and coaxially with respect to the hollow tube.

Abstract: A linear motor armature (1) is constructed by connecting in series a front module (10), at least one intermediate module (20), and a back module (30). The front module includes a first fluid passage, one end of which can be connected to the outside of the armature and the other end of which is open to the back edge (11B) of the front module, and a fifth fluid passage, one end of which can be connected to the outside of the armature and the other end of which is open at the back edge of the front module. The at least one intermediate module includes a second fluid passage, one end of which is open at the front edge (21A) of the intermediate module and the other end of which is open at the back edge (21B) of the intermediate module, and a fourth fluid passage, one end of which is open at the front edge of the intermediate module and the other end of which is open at the back edge of the intermediate module.

Abstract: A linear electromagnetic machine for generating a force acting between two members relatively movable along an axis, one of which is capable of producing a magnetic field the direction of at least part of which extends substantially radially of the said axis and the other of which comprises or includes a conductor, conveniently in the form of a coil, in which an electric current can flow substantially perpendicularly of the magnetic field so as to generate a force between the two members substantially parallel to the axis. The radial magnetic field is generated by permanent magnets orientated with their direction of magnetization axially, the pole pieces acting to concentrate the magnetic flux to follow a radial path through the coils.

Abstract: The present invention relates to an integrated system in which a bilateral permanent magnet excited synchronous motor part and a non-contact power feeding part are combined in order to generate a linear driving force and to feed an electric power without any contact.

Abstract: A linear motor includes a rotor (70) and a secondary member (80), wherein the secondary member (80) carries a cover for protection against mechanical damage, aggressive liquids etc. The cover (40) has low magnetizable material and is held in place by magnetic elements (30) of the secondary member. Thus, there is no need to secure the cover additionally by gluing etc and the cover can be easily replaced. The cover can be placed, preferably, as one piece upon the secondary member, which may be made of several secondary member elements, and carries a scale for controlling the position of the motor.

Abstract: A linear actuator includes a supporting unit with a stopper, a linear output unit, a movable unit, a magnetic flux generating unit and a control unit. The movable unit is connected to a stopper of the outer pipe at one end of the outer movable unit and to the linear output unit at the other end. The magnetic flux generating unit generates first magnetic fluxes. The movable unit has elasticity, and expands or contracts based on action of the first magnetic fluxes and the elasticity. The linear output unit linearly moves in response to the expansion or contraction of the movable unit.

Abstract: A valve assembly has a valve body defining a chamber with a controlled outlet. A stop and seat are spaced from each other and are supported within the chamber in axial alignment with the controlled outlet. A plunger reciprocably moves between the stop and the seat to open and close the controlled outlet through the operation of a solenoid assembly. The solenoid assembly includes a spool supported between two plates. An electrical coil is disposed around the spool for receiving electrical current and generating a magnetic flux. A primary magnetic flux loop forms a path around the spool, through the two plates, the plunger and the stop to move the plunger away from the controlled outlet. An annular magnetic flux regulator made of magnetic conductive material is disposed in the spool to provide a secondary bypass magnetic flux flow path for a portion of the generated magnetic flux during high amp-turn operating conditions.

Abstract: An electromagnetic x-y stage driver for a nano data storage system and a method for fabricating the coils of the same are provided. In the electromagnetic x-y stage driver, a cantilever tip array fixedly provided a medium for recording data to write data to or read data from each cell of the medium. Four coils are formed to be integrated with the medium in front of, behind, to the left of and to the right of the medium to move the medium. Four supporting beam are installed to an x-y stage body onto which a medium structure composed of the medium and the four coils is loaded such that the four supporting beam are connected to the four corners of the medium structure to support the medium structure. Four driving beams connect the upper portions of the supporting beam to the four corners of the medium structure to allow the medium structure to move in an x or y direction. Stiffeners are disposed at the four sides between the supporting beam to prevent the medium structure from rotating.

Abstract: A DC brushless voice-coil vibration motor, especially a small-sized micro-vibration motor that utilizes inductance coils and a weight object with a plurality of coplanar magnetic poles as the stator and rotor of the motor. The invention comprises a circuit board, at least two inductance coils and a weight object. The weight object is installed on the inductance coil and away from the motor center. It has a plurality of magnetic poles as the rotor of the motor. When current flows through the inductance coil, a magnetic field is generated so that the weight object starts to rotate under the electromagnetic interactions. Since the weight object is off the motor center, the motor gains vibrational energy during the rotation of the weight object.

Abstract: A linear electromagnetic machine for generating a force acting between two members relatively movable along an axis, one of which is capable of producing a magnetic field the direction of at least part of which extends substantially radially of the said axis and the other of which comprises or includes a conductor, conveniently in the form of a coil, in which an electric current can flow substantially perpendicularly of the magnetic field so as to generate a force between the two members substantially parallel to the axis. The radial magnetic field is generated by permanent magnets orientated with their direction of magnetisation axially, the pole pieces acting to concentrate the magnetic flux to follow a radial path through the coils.

Abstract: A starter motor assembly is provided having a solenoid assembly that includes a pull-in coil that is comprised of a plurality of coils connected in parallel. The plurality of coils may comprise three coils that are formed from a single wire cut and connected to form the pull-in coil. Also provided is a method of making a pull-in coil for a solenoid assembly for a starter motor assembly. The method includes the step of winding a wire down a length of a solenoid coil holder and then back up the length of the solenoid coil holder a plurality of times. Then, the wire is cut at points to form separate coils, each coil then having a first lead and a second lead opposite the first lead. The first leads of the coils are electrically connected together and the second leads of the coils are electrically connected together to form the pull-in coil comprised of multiple coils.

Abstract: The method is intended for manufacturing a microintegrated structure, typically a microactuator for a hard-disk drive unit and includes the steps of: forming interconnection regions in a substrate of semiconductor material; forming a monocrystalline epitaxial region; forming lower sinker regions in the monocrystalline epitaxial region and in direct contact with the interconnection regions; forming insulating material regions on a structure portion of the monocrystalline epitaxial region; growing a pseudo-epitaxial region formed by a polycrystalline portion above the structure portion of the monocrystalline epitaxial region and elsewhere a monocrystalline portion; and forming upper sinker regions in the polycrystalline portion of the pseudo-epitaxial region and in direct contact with the lower sinker regions. In this way no PN junctions are present inside the polycrystalline portion of the pseudo-epitaxial region and the structure has a high breakdown voltage.

Abstract: There is provided a provide a solenoid actuator which is capable of smoothly driving a driven member, with enhanced durability, and at the same time permits the stroke of the driven member to be changed with ease. A solenoid actuator drives a valve by an electromagnetic force such that the valve performs reciprocating motion. An armature is connected to the valve, for performing reciprocating motion in accordance with energization and deenergization of at least one electromagnet to thereby drive the valve such that the valve performs the reciprocating motion. The armature has two end faces extending in parallel with each other in a direction orthogonal to a direction of the reciprocating motion thereof. Two guide joints have respective two guide surface opposed to the two end faces of the armature, each formed with two armature guides.

Abstract: A prime mover using a split coil for magnetically inducing movement of a steel piston. The magnetic effects are emphasized in higher reciprocating movement by the proximate introduction of a permanent magnet. The prime mover is sparkless, brushless, quiet, low friction, and can operate on a wide array of voltages, including high frequency very low voltage signals.

Abstract: An electric nailing tool comprises a housing, a nail magazine for supplying nails, a spout attached to the nail magazine and having a passage communicated with the housing, a solenoid set, and a hammer. The solenoid set comprises at least two solenoids having a common through-hole for receiving the hammer. A percussion member is securely attached to an end of the hammer to move therewith, thereby driving a nail in the passage out of the spout upon percussion movement of the hammer. The solenoids are energized and de-energized in sequence to move the hammer back and forth along the common through-hole of the solenoids, thereby providing at least two impacting motions by the percussion member to the nail in the passage.

Abstract: In a preferred embodiment, a linear/rotary motor, including: a housing; an output shaft extending from the housing; a rotary motor disposed within the housing, the output shaft being given rotational motion by the rotary motor; a linear motor disposed within the housing; a linear shaft axially moveable by the linear motor; and a coupling to join the linear shaft and the output shaft to permit transfer of axial motion from the linear shaft to the output shaft but to isolate rotational motion of the output shaft from the linear shaft.

Abstract: The present invention provides, in a single phase-structure actuator, a rotor magnet structure having characteristics wherein detent torque is fully assured, and there is also a large rotation angle range.

Abstract: A cylinder-type linear synchronous motor including a stator of which assembling is facilitated. A movable element is constructed by fitting annular permanent magnets on a magnet mount 29 fixed on a direct-acting shaft so that N and S poles are alternately arranged in an axial direction thereof. A plurality of stator core units 35 fixed in a frame so as to be spaced from each other at equal intervals in a peripheral direction of the movable element. The stator core units each constituted by combining a plurality of stator core divisions with each other. Exciting windings each are constituted of an annular winding formed by annularly winding a conductive wire so as to surround the movable element in the peripheral direction thereof. The annular windings each are fitted at a part thereof in a slot formed between each axially adjacent two of magnetic pole sections of the stator core units.

Abstract: A linear actuator includes a supporting unit with a stopper, a linear output unit, a movable unit, a magnetic flux generating unit and a control unit. The movable unit is connected to a stopper of the outer pipe at one end of the outer movable unit and to the linear output unit at the other end. The magnetic flux generating unit generates first magnetic fluxes. The movable unit has elasticity, and expands or contracts based on action of the first magnetic fluxes and the elasticity. The linear output unit linearly moves in response to the expansion or contraction of the movable unit.

Abstract: A slider unit having built in a moving-coil linear motor is incorporated in a linear motion guide unit having a track rail and a slide. The slider unit is made easy in mounting to the appliances or works. The linear motion guide unit has the track rail and the slider movable lengthwise of the track rail. A linear motor is arranged between any one of widthwise opposing side walls of the track rail and the slider, and composed of a stator comprising a magnet yoke and field magnets, and a moving-coil assembly held on a side edge of a mount of the slider. The linear motor is preferred to make compact or slim in construction the linear motion guide unit, in which the linear motor is incorporated, thus making the slider unit simple in construction.

Abstract: An electromagnetic vibrator, includes a pair of electromagnets each having a core of E-configuration to define three parallel legs joined together at one side by a bridge, and a coil on the middle leg. The electromagnets are secured together with their bridges facing outwardly and with their legs aligned with, but spaced from, each other. A plunger carrying magnetisable material is disposed within the space between the legs of the electromagnets such as to be movable along the longitudinal axis of the plunger upon the energization of the coils of the electromagnets. A pair of springs yieldingly mount the opposite ends of the plunger to the electromagnets, each spring being yieldable in the direction of the longitudinal axis of the plunger and stiff in the direction of the transverse axis of the plunger.

Abstract: A multiphase linear motor has an elongated stator with a stack of permanent magnets end-to-end along its length and a coaxial drive coil configuration which is such as to leave a gap permitting mechanical support of the permanent magnets at least at intervals along the length of the stator intermediate its ends. Specifically the drive coils comprise sub-coils with arcuate turns which subtend less than 360° around the motor axis to leave free a gap for the aforementioned mechanical support.

Abstract: A new class of actuators and mechanisms use opposing repulsive magnetic forces. The repulsive forces are typically generated between a stationary magnet and a moving magnet, where the moving magnet is coupled to the mechanism output member. The mechanisms are generally configured such that the repulsive force from one electromagnet is opposed by a repulsive force from another electromagnet, where the opposing forces are simultaneously applied to the mechanism's output member. This configuration is similar in certain aspects to the way biological flexor and extensor muscles are configured in a musculoskeletal system. The opposing configuration allows for open loop control of position and stiffness. The actuator mechanism may have both rotary and linear motion output, and may have either a single degree of freedom or multiple degrees of freedom. Permanent magnets can be used to create a baseline repulsive force without electric power, and electromagnets can modulate the repulsive force magnitude.

Abstract: Sealed telescoping tubes are electromagnetically and fluidly actuated to provide linear motion and withstand loading. One of the tubes may be connected to a pressure or vacuum source, and the other sealed to a fixture to provide variable volume load augmentation in addition to electromagnetic actuation. Alternatively, both tubes may be sealed to provide a pneumatic or hydraulic spring with electromagnetic actuation, and the sealed tubes may also be connected to a pressure or vacuum source for load augmentation. A bearing may be used in conjunction with the seal between the tubes to provide resistance to traversal loads. The electromagnetic actuation includes a helical arrangement of coils or permanent magnets to provide linear motion or resistance. The coils can be arranged to be connected to a conventional multi-phase motor drive.

Abstract: The present invention relates generally to linear electric machines, capable of converting electrical current into mechanical work or mechanical work into electrical current. More specifically, this invention relates to an electric machine having a ferromagnetic vessel containing a single-pole magnetic field, end caps for reflecting magnetic energy and a shaft having an electromagnetic coil which moves relative to the magnetic field.

Abstract: A linear compressor includes a cylinder block in which a compressing chamber is formed; and an inner core having a plurality of electric steel plates disposed around the cylinder block. The cylinder block extends into spaces between the electric steel plates so that the cylinder block is integrally formed with the inner core. Each of the electric steel plates includes an insertion projection extending from a surface toward the cylinder block and an insertion step extending upward and downward from the insertion projection to form a concave between the surface and the insertion step, the cylinder block extending into the concave to interlock with the inner core.

Abstract: To provide a reciprocation motor capable to detect rotation angle of rotor accurately. Rotor 1 is a magnet having two poles to radial direction and comprises half-cylindrical magnets. Driving coils 5a and 5b are bound equally at coil board 3. Magnetic sensor 7 is fixed at outside and under side of driving coil 5b on coil board 3. Such a construction makes magnetic sensor hard to be influenced by flux generating caused by current flowing through driving coil 5b. Therefore, it is possible to improve position detecting accuracy of rotor 1.

Abstract: In a preferred embodiment, an actuator, including: a shaft (34); a solenoid (24), having a coil (40) and a core (42), disposed at a first selected position on the shaft, with the core being fixedly attached to the shaft such that energization of the coil will cause the shaft to move axially; and a rotary motor (22), having a stator (30) and a rotor (32), disposed at a selected second position on the shaft, with the shaft passing through the rotor, an external surface of the shaft and an internal surface of the rotor having complementary engaging surfaces such that rotation of the rotor will cause rotation of the shaft and axial motion of the shaft will be isolated from the rotor.

Abstract: A voice coil linear actuator includes a bobbin connected to a voice coil, a center pole piece, a main magnet, and an outer pole and housing. An auxiliary magnet is constructed and arranged for attachment to the center pole piece such that the center pole piece is sandwiched between the auxiliary magnet and the main magnet. The main magnet has a first magnetic polarization (e.g., North) adjacent to the center pole piece at a first end of the main magnet. The auxiliary magnet has a second magnetic polarization (e.g., North) adjacent the center pole piece, such that fringing fields from the auxiliary magnet substantially cancel fringing fields from the main magnet. Consequently, substantially all fringing fields from the actuator are substantially contained with the actuator. Fields at the magnetic head in a tape drive unit are less than about five Orsted.

Abstract: A linear motor comprising prismatic inner yokes each constructed in a manner that a large number of sheets each having a generally rectangular configuration and having a high magnetic permeability are piled up each other and outer yokes each constructed in a manner that a number of sheets each having a generally rectangular configuration and having a high magnetic permeability are piled up each other. Each of coils is wound around a central portion of three magnetic pole portions of the outer yoke to alternately establish different magnetic poles along a direction of an axis of the linear motor. A surface of the outer yoke, holding the magnetic pole portions, is disposed in an opposed relation to the inner yoke to define a predetermined gap therebetween so that the inner yoke and the outer yoke form each of a plurality of yoke blocks. The yoke blocks are placed around the axis so that the sheet piling-up direction is perpendicular to a diametrical direction of a shaft.