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LINEAR-MOVEMENT MOTORS

Subclass of:

318 - Electricity: motive power systems

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Class / Patent application numberDescriptionNumber of patent applications / Date published
318135000LINEAR-MOVEMENT MOTORS46
20090102403VCM CONTROL CIRCUIT - A method of controlling a moving part of a voice coil motor to move from an first position to a second position, wherein the position of the moving part is controlled by the level of an electrical signal applied to a coil of the voice coil motor, a first level of the electrical signal corresponding to the first position, and a second level of the electrical signal corresponding to the second position, the method including: at a first time, changing the electrical signal from the first level to an intermediate level, the intermediate level being chosen such that a peak overshoot of the moving part corresponds to the second position; and at a second time calculated to correspond to a delay of half an oscillation period of the moving part after the first time, changing the electrical signal to the second level.04-23-2009
20090218963Linear motor automatic control circuit assembly for controlling the operation of a 3-phase linear motor-driven submersible oil pump of an artificial oil lift system - Connected to a 3-phase linear motor of a submersible oil pump of a crude oil production system, a linear motor automatic control circuit assembly is disclosed to include a linear motor power supply circuit, a CPU, an insulated gate bipolar transistor driving circuit, a current detection circuit, a temperature sensor, a fluid depth sensor, a function setting and status display circuit, and a circuit assembly power supply circuit for controlling the operation speed of the linear motor subject to the submergence depth of the linear motor in the oil well.09-03-2009
20100097014 Control of a linear motor - A linear electric motor has a fixed primary comprising a stator that is divided into a number of sections, a translating secondary that has an operative length that is longer than any two adjacent sections of the stator in the form of a reaction plate, and a connecting means for connecting only those sections of the stator that are covered, either fully or partially, by the reaction plate. The stator sections are categorised in three groups—two groups of representative sections and an ordinary group of sections. The first and second representative sections alternate with ordinary sections between them. The position of the reaction plate relative to the stator is determined by monitoring current in the active representative sections. The length of the reaction plate is equal to the distance from the beginning of the first representative stator section to the end of the ordinary stator section immediately following the next second representative stator section. Power is supplied to each stator section individually with power being supplied in a modulated manner to end active stator sections that are only partially covered by the reaction plate. Current to the first and second representative sections is used to determine the position of the stator as well as measurement of the inductance of the stator sections.04-22-2010
20130049647Force Distribution Method for Stage Systems Utilizing Dual Actuators - According to one aspect, a method for controlling a stage that is a part of a stage apparatus and is coupled to a voice coil motor (VCM) and an EI-core actuator arrangement includes driving the stage, identifying a frequency associated with the stage, and determining whether the frequency is below a frequency setpoint. The method also includes providing a first control force on the stage using the EI-core actuator arrangement when it is determined that the frequency is below the frequency setpoint, and providing the first control force on the stage using the VCM when it is determined that the frequency is not below the frequency setpoint.02-28-2013
20090302786LINEAR STEPPING MOTOR - A linear motor includes a stator having teeth symmetrically formed on upper and lower surfaces thereof at regular pitch; a movable member including upper cores disposed above the stator, lower cores disposed below the stator in symmetrical with the upper cores, and yoke parts connecting the upper and the lower cores around the stator, wherein the upper and lower cores have upper and lower coils wound therearound, respectively; at least one gap sensor to detect the gap between the stator and the upper or lower core and the inclination of the movable member; a controller performing the levitation control by adjusting the amplitudes of currents applied to the upper and lower coils, based on the gap variation, and driving the linear motion by changing the current phases; and a multichannel voltage-to-current power amplifier of which each channel is connected to each coil of the upper and lower cores.12-10-2009
20090091276Linear motor and method for operating a linear motor - A linear motor includes a primary part arranged as a guideway stator and at least one secondary part that is movable with respect to the primary part, the at least one secondary part having device(s) for controlling the generation of a magnetic field, causing its motion, in the primary part. It is possible to avoid costly control devices for the application of current to the stator.04-09-2009
20130119897Controlled Motion System - A controlled motion system having a plurality of movers controlled as they travel along both smart and simple sections of a track. The controlled motion system comprises a control system for controlling the speed of a mover as it travels along a simple section, and permits the pitch or distance between movers to increase or decrease as they travel along a simple section. In a preferred embodiment the controlled motion system includes at least one coupling feature having a driving feature on a simple section for engaging and operably driving a driven feature on each mover such that positive control of each mover is maintained throughout its transition from a smart section to a simple section.05-16-2013
20090045760Linear Drive for Sliding Doors or the Like - The invention is directed to a linear drive for sliding doors or the like, particularly linear drives based on linear motors. A linear drive, according to the invention, for at least one part which is movable along a movement path, particularly a sliding door leaf, has at least one linear motor for the at least one part. A stator part of the linear motor is received in a receiving profile so as to be prevented from falling out. The receiving profile is constructed to be arranged at a fastening device, which is arranged in turn on the installation side of a wall portion or top portion. Accordingly, the stator part and receiving profile form a module or unit, which can be mounted in its entirety. Therefore, a person performing the mounting can use the receiving profile for mounting, which helps to reduce the risk of damaging the stator part, for example.02-19-2009
20100001667CONTROL CIRCUIT OF A FULL-BRIDGE STAGE - A control circuit for a full-bridge-stage to drive an electric load includes PWM generation circuitry for generating first and second PWM signals so that a difference between duty-cycles of the PWM signals represents an amplitude of a drive current. A logic XOR gate is input with the first and second PWM signals and generates a logic XOR signal. A logic sampling circuit generates a logic driving command of a half-bridge of the full-bridge stage, a logic value of which corresponds to a sign of the drive current, by sampling one of the first and second PWM signals based upon active switching edges of the logic XOR signal. A second XOR gate is input with the logic XOR signal and the logic driving command and generates a third PWM driving signal of the other half-bridge of the full-bridge stage, a duty-cycle of which corresponds to the amplitude of the drive current.01-07-2010
20090160372DRIVING DEVICE - In order to provide a driving device that is capable of eliminating sticking of a movable member due to nonuse, the driving device includes a drive shaft that reciprocates in axial directions with expansion and contraction of an electromechanical transducer element, a movable member that frictionally engages with the drive shaft, and a drive circuit that inputs drive voltage into the electromechanical transducer element, the drive circuit outputting drive operation pattern voltage having a frequency (fd06-25-2009
20080211436Measuring Apparatus with a Measuring Head for Determining the Position of a Primary Part on a Secondary Part and Method for Determining the Position of a Primary Part on a Secondary Part wtih a Measuring Head - The invention relates to a measuring apparatus comprising a sensing head (09-04-2008
20080284360BLOCK SWITCHING TRANSIENT MINIMIZATION FOR LINEAR MOTORS AND INDUCTIVE LOADS - A block switch controller for a linear motor is disclosed, the block switch controller having a motor current threshold profile controlling the switching of a plurality of block switches in a linear motor. Also, a block switch controller for a linear motor comprising a closed loop vector current controller that incorporates a delay state having a feedback gain is disclosed. Additionally, a method of switching a plurality of block switches that minimizes switching transients is provided. Finally, an article of manufacture containing computer code implementing a modeling and simulation program for modeling a linear motor system is provided.11-20-2008
20120293094VIBRATION DAMPING APPARATUS, ELECTRIC ACTUATOR DRIVING APPARATUS AND VEHICLE - A vibration damping apparatus including reference wave production section that produces a reference wave; a fundamental order adaptive algorithm block that calculates fundamental order adaptive filter factors from a vibration detection signal and the reference wave and produces a fundamental order vibration damping current instruction; an amplitude detection section that calculates a peak current value of the fundamental order vibration damping current instruction; and a fundamental order current excess detection section that derives a fundamental order current upper limit value from the fundamental frequency to produce a fundamental order current upper limit excess signal that is output to the fundamental order adaptive algorithm block, which revises the fundamental order adaptive filter factors in a direction in which the vibration damping current instruction is limited within a range.11-22-2012
20080272716LINEAR INDUCTION MACHINE CONTROL SCHEME, SYSTEMS, AND METHODS - A method and system for a control scheme for linear induction machines. The control scheme includes a maximum energy conversion ratio and a maximum acceleration and deceleration for linear induction machines.11-06-2008
20080265807Linear Motor and Transducer Arrangement Therefor - An improved linear motor which compensates for manufacturing or assembly errors in the positioning of the magnetic field detectors. The linear motor synthesises a correction signal which can be simply combined (for example added) to the output of one of the magnetic field detectors so as to ensure that the magnetic field detector outputs have the correct phase relationship. This in turn ensures that accurate positioning of the rotor relative to the stator can be achieved. In a preferred embodiment, a deliberate error is introduced into the positioning of the magnetic field detectors and this error, plus any error due to manufacturing or assembly tolerances, is corrected using the correction signal. This allows a simplified correction circuit which only corrects for phase offset errors in one direction to be used.10-30-2008
20120068635Linear Actuator and a Table Comprising a Linear Actuator as well as a Motor for the Linear Actuator - An embodiment linear actuator for an electrically adjustable piece of furniture includes a brushless DC motor arranged to effect a linear movement of the linear actuator, as well as a control device for controlling the motor.03-22-2012
20090015181Machine Tool with a Functional Unit Having a Linear Drive and Linear Drive for Same - A machine tool is provided that has a linear drive by means of which a movement unit connected in motion with a functional unit is movable in two axis directions of a movement plane. The linear drive includes two drive units. The primary parts or the secondary parts of the two drive units are attached to the movement unit. The primary part or the secondary part of the one drive unit is disposed in that case on that side of the movement unit which, perpendicularly to the movement plane of the movement unit, is opposite the side of the movement unit provided with the primary part or the secondary part of the other drive unit.01-15-2009
20090195195Position Feedback Device for a Linear Motor - A position feedback device for a linear motor comprises three linearly-arranged Hall sensors. The three Hall sensors are connected to a mover, respectively. The direction in which the Hall sensor in the middle of the three Hall sensors is reverse to the direction in which the other two Hall sensors of the three Hall sensors are connected, so that the arrangement distance of the three Hall sensors can be reduced, and the size of the position feedback device can be reduced.08-06-2009
20100253251DEVICE FOR SUPPLYING ENERGY TO A LONG STATOR WINDING HAVING MULTIPLE WINDING SECTIONS - A device for supplying energy to a long stator winding having multiple winding sections. The device includes an energy source, a supply line connected to the energy source, section switches that are connected to the supply line and that each have a connection for connecting the switch to one winding section each. The device is configured to enable reactive (idle) power compensation independently of the closed-loop control of the energy source. The device for the reactive power compensation is configured to adjust the impedance of the device.10-07-2010
20090115357Detection and Delimitation of Maximum Stator Currents - A device for driving a magnetic levitation train has at least one controllable power supply unit that feeds at least one multi-phase power supply line, and a long stator with stator windings that extend in switching sections of the long stator. Each switching section can be connected to at least one of the power supply lines via an assigned section feed switch and each stator winding has at least one assigned current sensor for detecting a current and at least one assigned evaluation unit connected to the sensor. In order to permit a simple, precise overcurrent protection, each current sensor is configured to detect the current in one phase of each assigned stator winding and the evaluation unit is configured to deactivate the section feed switch, if the current detected in each case exceeds a previously defined threshold value.05-07-2009
20090026985Method for Actuating an Electromagnetic Valve - A method for is provided actuating at least one electromagnetic valve containing at least one coil, which can be excited by an excitation current, and an armature, in which the excitation current can be set such that, in response to a signal for actuating the armature from one position into another position, it causes the actuator to move as a result of an excitation current threshold being exceeded, and is kept at a value which is lower by comparison in order to hold the armature in a specific position. The excitation current, which is greater than zero but below the excitation current threshold, is applied at least temporarily to the electromagnetic valve even if no signal for actuating or for holding the armature is present.01-29-2009
20110210686ELECTRIC MACHINE - An electric machine including: a first part, being a stator or rotor/runner, including a first segment with a first number of mutually spaced poles; a second part, being a rotor/runner or stator, including a second segment with a second number of mutually spaced poles arranged to transduce between electrical and mechanical energy by magnetic interaction with the poles of the first segment, the second segment having substantially the same length as the first segment; and permanent magnets in the poles of the first or second parts, wherein the second number differs from the first number by one to substantially reduce the magnetic interference forces in the direction of motion, wherein gap depths in gaps between the poles of each part are sufficiently deep to substantially attenuate magnetic interactions between a body of each part and the poles of the other part, thereby reducing magnetic interference forces between the first part and the second part, and wherein each part is symmetrical in a direction transverse a direction of motion between the first part and the second part and transverse a depth of the parts for substantially balancing magnetic forces acting perpendicular to the direction of motion.09-01-2011
20100164413DRIVING CIRCUIT FOR VOICE COIL MOTOR AND METHOD THEREOF - The invention provides a driving circuit for a voice coil motor. In one embodiment, the driving circuit includes a logic circuit, a digital-to-analog converter, and an output circuit. The logic circuit generates a series of samples of a digital output signal according to a digital input signal, wherein the samples of the digital output signal sequentially alter from a first input value of the digital input value to a second input value of the digital input signal according to an alteration pattern determined by a mode selection signal. The digital-to-analog converter converts the digital output signal to an analog output signal. The output circuit generates a driving current signal according to the analog output signal for driving the voice coil motor.07-01-2010
20090218964DRIVING APPARATUS, INDUSTRIAL INSTRUMENT, EXPOSURE APPARATUS, AND DEVICE MANUFACTURING METHOD - A driving apparatus which electrically drives a component built in an industrial instrument, comprises a housing including a supply inlet and an exhaust outlet, a fan configured to form an air current so that air is taken into the housing through the supply inlet and exhausted from inside the housing through the exhaust outlet, a driving circuit block which is accommodated in the housing so as to be cooled by the air current, and configured to electrically drive the component, and a cooling unit configured to regulate a temperature of the air exhausted from inside the housing through the exhaust outlet so as to decrease a temperature difference between the air taken into the housing through the supply inlet and the air exhausted from inside the housing through the exhaust outlet.09-03-2009
20100181945Control Apparatus and Method for Linear Synchronous Motor - The start timing of the pole position inference process of the linear motor installed vertically is delayed by a predetermined time after instruction of brake release. For example, from (1) increasing of the thrust instruction value of an ASR control system up to a predetermined value, (2) the movement (falling) distance of the moving part, or (3) the moving (falling) speed of the moving part, the release condition of the brake is detected and moreover after a predetermined time, the inference process of the pole position is started. The inference process of the pole position of a synchronous motor is fit to the release timing of a brake and a malfunction of the inference process and a runaway (falling in the vertical drive) of a moving part are prevented.07-22-2010
20100072924METHOD FOR CONTROLLING AC LINEAR MOTORS, DEVICE FOR DRIVING AC LINEAR MOTORS, AND SYSTEM OF AC LINEAR MOTORS - Provided is a method for controlling a plurality of AC linear motors of identical specifications which are connected each other and operated synchronously so that they appear to operate as a single linear motor having desired power.03-25-2010
20110175555PROCEDURE AND DEVICE FOR CONTROLLING ACTUATORS - A procedure for controlling actuators within an on-board power system, which provides different operating voltages and temporal on-board power voltage changes. The actuator or actuators are controlled with different pulse-width modulated control signals, whereby the pulse-width and the cycle duration of the control signals can be adjusted independent of each other and are adjusted independent of the actually applied on-board power voltage. Control signals for the actuators can be specified by a control unit. The actuator or actuators can be controlled with the aid of the control unit by different pulse-width modulated control signals, whereby the pulse-width and the cycle duration of the control signals can be adjusted independent of each other; and the control unit provides devices for detecting the actually applied on-board power voltage and driver units.07-21-2011
20110101896LINEAR MOTOR DEVICE - Provided is a linear motor device which is compact even when a stroke is increased, which can reduce heat generation, and which can eliminate damping force caused by circulating current. The linear motor device includes a linear motor that includes a movable member having a plurality of fields and a stator in which a plurality of armatures including polyphase coils are arranged in line in the moving direction of the movable member, and a controller that sequentially outputs control commands to current amplifiers respectively connected to the armatures in accordance with the relative position of the movable member. The controller selectively outputs the control commands to only the current amplifiers corresponding to the armatures which are opposite the movable member such that the armatures are positioned within a range corresponding to the length in the moving direction of the movable member.05-05-2011
20110062901Arrangement of Stator Modules in a Linear Motor - A linear motor is disclosed, which has a stator and at least one rotor, the stator having at least two stator modules. Each stator module has a coil arrangement and, seen in longitudinal extension of the respective stator module, at least at one end, a displacement sensor. Each stator module is disposed along a travel path of the respective rotor in an area of the respective stator module. Each displacement sensor has a detection range, within which it can detect a rotor, as long as the latter is located at least partially in the detection range. Each coil arrangement has an interaction range, within which, in case of energizing, the coil arrangement comes into interaction with the rotor and urges the latter in a driving direction, as long as the rotor is located with at least one portion in the interaction range. The at least two stator modules and the at least one rotor are disposed such that, at all times, a portion of the at least one rotor is located at least in the detection range of a displacement sensor and another portion of this rotor at least in the interaction range of a coil arrangement of the at least two stator modules.03-17-2011
20100295488VIBRATORY DRIVING DEVICE - A vibratory driving device 11-25-2010
20110080123LINEAR-ROTARY ACTUATORS, ACTUATOR SYSTEMS, AND METHODS OF OPERATION THEREFOR - In an embodiment, an actuator includes a plurality of stator windings adapted to produce a first stator magnetic field that translates along a stator axis, and to produce a second stator magnetic field that rotates around the stator axis. In addition, the actuator includes a rotor, coupled to a shaft, and positioned within a central stator channel. The rotor is adapted to produce a first rotor magnetic field that translates along a shaft axis and to produce a second rotor magnetic field that rotates around the shaft axis. An actuator system includes an actuator and an actuator controller unit, which is adapted to produce actuator inputs. An embodiment of a method for controlling the actuator includes providing actuator inputs to produce a translating magnetic field in the stator, a translating magnetic field in the rotor, a rotating magnetic field in the stator, and a rotating magnetic field in the rotor.04-07-2011
20110109252LINEAR SCALE, LINEAR MOTOR, AND LINEAR MOTOR CONTROLLER - Disclosed is a linear scale for obtaining a distance from a reference point. A scale detection mechanism is adapted to output waveform signals of the same phase. Also the scale detection mechanism corresponds to a magnetic flux density generated by magnetic bodies of a scale element. The scale detection mechanism may be sensors. The sensors are arranged at even intervals corresponding to a scale length of the scale element. The sensors are adapted to output sine-wave signals having the same phase to continuously detect the scale element in a movement direction of the scale element. The scale element has opposite ends each has the same polarity and configured such that an output voltage of the single sensor detecting the end of the scale element is reduced to one-half of an output voltage of the single sensor detecting the remaining portion of the scale element.05-12-2011
20110304285MOTOR DRIVE CIRCUIT - A motor drive circuit includes: a digital filter configured to attenuate amplitude in a frequency band including a resonance frequency of an actuator in a target current signal, the target current signal being a digital signal indicative of a target value of a drive current, the drive current being supplied to a voice coil motor configured to drive the actuator; a digital-analog converter configured to convert an output signal of the digital filter into an analog signal, and output the converted analog signal as a current control signal; and a drive circuit configured to supply the drive current to the voice coil motor according to the current control signal.12-15-2011
20110304286BLOCK SWITCH CONTROLLER COMPRISING A CLOSED LOOP VECTOR CONTROLLER INCORPORATING A DELAY STATE HAVING A FEEDBACK GAIN - A block switch controller for a linear motor is disclosed, the linear motor having a plurality of motor blocks, a shuttle which is propelled by the magnetic forces generated by a motor current passing through the motor blocks, a plurality of motor block switches selectively passing the motor current through the motor blocks, and a plurality of position sensors determining the position of the shuttle relative to the motor blocks, wherein the controller comprises a closed loop vector controller that incorporates a delay state having a feedback gain.12-15-2011
20120098469LINEAR MOTOR - A linear motor includes a slider unit having a magnet row in which plural permanent magnets are arranged in series so that the same poles are opposed to each other, a stator unit including electromagnetic coils for plural phases arranged along a movement direction of the slider unit, and plural magnetic detector devices, wherein the plural magnetic detector devices are provided in response to the phases of the electromagnetic coils for plural phases and detect magnetic flux radially extending in a direction perpendicular to the arrangement direction of the permanent magnets at boundaries between the permanent magnets of the magnet row and output signal waveforms for plural phases at phases equal to phases of waveforms of back electromotive forces generated in the respective electromagnetic coils for plural phases when the magnet row moves.04-26-2012
20100097015Distance measurement with capacitive sensor - Circuits and methods to read out capacitive sensors for distance measurement used by a position control system having a high accuracy and low noise have been disclosed. The ratio or difference of the capacitances of two sensor capacitors is used to determine the distance of an object from a target position. A sense amplifier is using auto-zero methods to achieve a long term stability. A sample-and-hold circuit using double correlated sampling methods minimizes noise. Low cost capacitors can be used with the sample-and-hold circuit because not the absolute value of capacitances but only the ratio of capacitances are relevant. A high resolution is ensured also by significant over-sampling of the control loop.04-22-2010
20100066276Method For Absorbing The Displacement Of A Plunger In A Linear Electrodynamic Motor Under The Influence of An External Force - The invention relates to a method for absorbing the displacement, under the influence of an external force, of at least one plunger (03-18-2010
20110156619LINEAR SYNCHRONOUS MOTOR CONTROL METHOD AND CONTROL APPARATUS - It makes possible to control a movable element to be smoothly movable by a sensor-less vector control in an equal speed area, without using a position sensor, and possible to perform a stop control and control it in a low speed area. In a case when a moving speed of the armature is faster than a predetermined speed preliminarily determined within a range in which the movable element is moved in synchronous with movement of the magnetic field generated by the armature by a predetermined sensor-less vector control, the current passing through the armature is controlled by the sensor-less vector control, and in a case when the moving speed of the armature is slower than the predetermined speed, in a d-q coordinate in which a d-axis represents a direction of a flux generated by field and a q-axis represents a phase advanced by π/2 with respect to the d-axis, a d-axis armature current and a q-axis armature current are controlled so that a d-axis electric angle is produced, and current passes through the d-axis armature and does not pass through the q-axis armature.06-30-2011
20120249019POSITIONER - A coil of an electro-pneumatic converting portion is connected in parallel with a constant voltage circuit. An electric current regulating portion is provided in a supply line for an electric current to the coil. The regulating value for the electric current in this electric current regulating portion is controlled by an instruction from a CPU The CPU detects, as a present supply electric current, an actual value for the supply electric current from a higher-level system, and evaluates whether or not there is, in the present supply electric current, a surplus electric current that can be directed to the electro-pneumatic converting portion. The supply electric current can be in excess of 4 mA and is the surplus electric current, and if there is a surplus electric current, the a command is sent to the electric current regulating portion so as to allocate that surplus electric current to the coil.10-04-2012
20090058328Motor Driving Circuit - A motor driving circuit for controlling a current amount flowing through a motor coil includes: a comparator configured to output a comparison signal indicating a comparison result between a set current amount and a current amount based on an inputted set current signal according to the set current amount and a current signal according to the current amount flowing through the motor coil; a current control signal update circuit configured to update a current control signal for controlling the current amount flowing through the motor coil in a stepwise manner so that the current amount flowing through the motor coil is changed to the set current amount in a stepwise manner, based on the comparison signal outputted from the comparator; and a driving circuit configured to drive the motor coil based on the current control signal outputted from the current control signal update circuit.03-05-2009
20120187873LINEAR MOTOR DRIVING SYSTEM AND LINEAR MOTOR CONTROL METHOD - In a linear motor in which a plurality of stators are arranged in a distributed manner, a position of the movable member is controlled while preventing unnecessary speed variation of the movable member while performing smooth driving. A driving device calculates a deviation between a position command from a controller and a position detected by a position sensor of a corresponding stator, a position controlling is performed calculating speed command to be utilized for speed controlling of the movable member based on the deviation and a position gain, a deviation is calculated at a time when the movable member enters a control area in which at least a part of the magnet portion opposes to the coil of the stator within an area of which position is detected by the position sensor of the corresponding stator, and the position of the movable member is back-calculated from deviation from the position command and the position command, and the position detected by the position sensor is corrected with the calculated position being as the position of the movable member at a time when the movable member enters the control area.07-26-2012
20120262095AIR GAP CONTROL SYSTEMS AND METHODS - In one embodiment, an apparatus includes a first member that supports a magnetic flux carrying member and a second member that supports a magnetic flux generating member disposed for movement relative to the first member. An air gap control system is coupled to at least one of the first member or the second member and includes an air gap control device that is separate from a primary magnetic flux circuit formed between the first member and the second member. The air gap control device is configured to exert a force on one of the first and second members in response to movement of the other of the first and second members in a direction that reduces a distance between the first and second members to maintain a minimum distance between the first and second members and/or substantially center the one of the first and second members within the other.10-18-2012
20120081043CONTROL OF A LINEAR MOTOR - Disclosed is a linear electric motor having a fixed primary comprising a stator divided into a number of sections, including a translating secondary having an operative length longer than any two adjacent sections of the stator in the form of a reaction plate, and a connecting means for connecting only those sections of the stator that are at least partially covered by the reaction plate. The position of the reaction plate relative to the stator is determined by monitoring current in the active representative sections. Power is supplied to each stator section individually, with power supplied in a modulated manner to end active stator sections only partially covered by the reaction plate. A measurement of the current to the active representative section is used to control output voltage to all energized stator sections and is used to determine the change in position of the reaction plate.04-05-2012
20120091928POSITION DETECTOR FOR MOVING MAGNET TYPE LINEAR MOTOR - The present invention provides a position detector which can detect the position of a mover on the side of a stator, and which realizes detection with high accuracy in a moving magnet type linear motor.04-19-2012
20110309775Method and Apparatus for Contorlling a Linear Motion System - A method of controlling a linear motion system has a linear synchronous motor comprising a stator and at least two carrier units moveable in relation to the stator, the stator comprising a number of coil units, each of the at least two carrier units comprising a magnetic unit including an array of alternate-pole magnets having a regular magnet pole-pitch, wherein in order to form a train the at least two carrier units are arranged relative to each other so that the mutual distance between two identically poled magnets of two different magnetic units is an integer multiple of the magnet pole-pitch.12-22-2011
20120139455DISTRIBUTED-ARRANGEMENT LINEAR MOTOR AND CONTROL METHOD OF DISTRIBUTED-ARRANGEMENT LINEAR MOTOR - A distributed-arrangement linear motor in which stators are arranged in a distributed manner and a method of controlling the distributed-arrangement linear motor are provided. The linear motor 06-07-2012

Patent applications in class LINEAR-MOVEMENT MOTORS