Linear-movement Motors Patents (Class 318/135)
  • Patent number: 8102132
    Abstract: A starting apparatus is disclosed for at least two synchronous machines, which starting apparatus includes an exciter unit which is provided for each synchronous machine and is associated with the respective synchronous machine. Each exciter unit can be connected to the field winding of the associated synchronous machine. A superordinate control unit is provided, with the superordinate control unit being connected via a communication link to each exciter unit. Furthermore, the starting apparatus includes at least one stator feed unit and at least one switching device, which is provided for each stator feed unit and is associated with the respective stator feed unit, in which case the respective switching device can be connected to the associated stator feed unit, the respective switching device can be connected to at least one synchronous machine, and the switching devices can be connected to one another when there are a plurality of switching devices.
    Type: Grant
    Filed: May 26, 2009
    Date of Patent: January 24, 2012
    Assignee: ABB Schweiz AG
    Inventors: Tobias Keller, Rudolf Wieser
  • Patent number: 8100668
    Abstract: An apparatus and method for controlling an operation of a reciprocating compressor are disclosed in which a point of inflection with respect to an operation frequency of the reciprocating compressor is detected at a point of time when a phase difference between current and stroke is uniformly maintained, and an operation of the reciprocating compressor is controlled upon recognizing the detected point of inflection with respect to the operation frequency as a point TDC=O. The apparatus for controlling an operation of a reciprocating compressor includes: a control unit for detecting a phase difference between current and stroke and outputting a frequency inflection point detect signal or a frequency variable signal; and a stroke reference value control unit for determining whether a frequency inflection point has been detected or not according to the frequency inflection point detect signal and outputting a stroke reference value control signal based on the determining result.
    Type: Grant
    Filed: December 28, 2006
    Date of Patent: January 24, 2012
    Assignee: LG Electronics Inc.
    Inventors: Jae-Yoo Yoo, Ji-Won Sung, Chel-Woong Lee
  • Patent number: 8093842
    Abstract: A position controlled drive mechanism and a control method for positioning a drive mechanism are introduced. A sensor generates a displacement signal indicative of a displacement of a movable stop driven by an electric motor. A controller controls rotation of the electric motor. The controller also calculates a position of the movable stop based on the displacement signal. The controller includes at least two modes of operation in which the controller controls the electric motor to rotate its shaft to reach a selected position of the movable stop; controls a voltage or current supplied to the electric motor to maintain a current position of the movable stop; controls the electric motor to rotate the rotatable shaft in a selected direction until an external object hinders the rotation of the rotatable shaft; and controls the electric motor to assist an externally initiated rotation movement detected by the sensor.
    Type: Grant
    Filed: December 21, 2006
    Date of Patent: January 10, 2012
    Assignee: Exact Products, Inc.
    Inventors: Bruno Bergeron, Eric Bergeron, Vincent Noel
  • Patent number: 8084969
    Abstract: A linear motion control device for use in a linear control system is presented. The linear motion control device includes a coil driver to drive a coil that, when driven, effects a linear movement by a motion device having a magnet. The linear motion control device also includes a magnetic field sensor to detect a magnetic field associated with the linear movement and an interface to connect an output of the magnetic field sensor and an input of the coil driver to an external controller. The interface includes a feedback loop to relate the magnetic field sensor output signal to the coil driver input.
    Type: Grant
    Filed: October 1, 2007
    Date of Patent: December 27, 2011
    Assignee: Allegro Microsystems, Inc.
    Inventors: Paul David, Shaun D. Milano
  • Publication number: 20110309775
    Abstract: 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.
    Type: Application
    Filed: October 23, 2009
    Publication date: December 22, 2011
    Applicant: ROBERT BOSCH GMBH
    Inventors: Walrick Dirkx, Wilco Pancras
  • Patent number: 8080967
    Abstract: The brushless electric machine includes a first drive member (30U) having a plurality of permanent magnets (32U); a second drive member (10) having a plurality of electromagnetic coils and capable of movement relative to the first drive member (30U); and a third drive member (30L) disposed at the opposite side from the first drive member (30U) with the second drive member (10) therebetween. The second drive member (10) has magnetic sensors (40A, 40B) for detecting the relative position of the first and second drive members. The third drive member (30L) has at locations facing the permanent magnets of the first drive member (30U) a plurality of magnetic field strengthening members (32L) for strengthening the magnetic field at the location of the second drive member (10) in conjunction with the permanent magnets.
    Type: Grant
    Filed: January 11, 2011
    Date of Patent: December 20, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Keshatoshi Takeuchi, Mamoru Sugimoto, Yojiro Okakura
  • Patent number: 8079825
    Abstract: A method of protecting a cylinder of a compressor comprising a piston, a linear permanent magnet (PM) having a coil and a magnet, and a sensor-less control of the PM for moving the piston in and out of the cylinder. The method including the steps of receiving a reference position of the piston from a temperature control loop; deriving a compensation voltage and a load spring effect information from a current through the coil; providing a model input voltage to a model of a mechanical structure of the compressor for predicting position of the piston, the model input voltage comprising a first voltage derived from the reference position; a compressor input voltage comprising the first voltage and the compensation voltage; and using a position control loop to recognize when the maximum compression ratio is desired and controlling the piston to achieve maximum compression ratio without causing damage to the discharge valve.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: December 20, 2011
    Assignee: International Rectifier Corporation
    Inventor: Cesare Bocchiola
  • Publication number: 20110306467
    Abstract: A load device for an apparatus for physical exercise that comprises a device that generate the load called linear motor, a micro controller, a series of sensors (dynamic, diagnostic and physiological) and a user interface.
    Type: Application
    Filed: October 12, 2009
    Publication date: December 15, 2011
    Inventor: Enrico Massa
  • Publication number: 20110304286
    Abstract: 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.
    Type: Application
    Filed: June 16, 2011
    Publication date: December 15, 2011
    Applicant: ELECTRO STANDARDS LABORATORIES
    Inventor: RAYMOND B. SEPE, JR.
  • Publication number: 20110304285
    Abstract: 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.
    Type: Application
    Filed: June 10, 2011
    Publication date: December 15, 2011
    Applicant: ON SEMICONDUCTOR TRADING, LTD.
    Inventors: Tsutomu Shimazaki, Akira Suzuki, Takeshi Arai
  • Patent number: 8074579
    Abstract: A magnetically levitated transport system moves a suspended cargo such as passengers and freight. A linear motor uses a track stator about which a “rotor” moves linearly. Stator and rotor circuits interact electromagnetically to maintain a gap between the moving and fixed elements. Tractor coils are embedded within the track to produce thrust through electromotor action with magnets aboard the rotor. The rotor is configured in a triangular shape as is the track with opposing electromagnets positioned for creating mutual repulsion forces. A pulsed direct current in the stator circuit, derived from conventional alternating current taken from the power grid, is used to create an induced current in the rotor, which, in turn is used to energize rotor electromagnets.
    Type: Grant
    Filed: May 21, 2010
    Date of Patent: December 13, 2011
    Inventor: Dumitru Bojiuc
  • Publication number: 20110298480
    Abstract: Circuits and methods for compensating the impact of parasitic capacitances on capacitive sensors have been achieved. The charge of a compensation capacitor assigned to each capacitive sensor is used to neutralize the charge of the parasitic capacitor.
    Type: Application
    Filed: June 7, 2010
    Publication date: December 8, 2011
    Inventors: Frank Kronmueller, Horst Knoedgen
  • Patent number: 8067917
    Abstract: A system and control method mitigates hysteresis of an adjustable component in the system. A control module can allow small control changes to be effected to the component within limits of the component's and/or the system's normal hysteresis band. The control method can allow finer, more accurate and more aggressive control to be obtained from the component. The system and method can utilize two separate control regimes to control adjustments to the component. The first control regime can control changes larger than a hysteresis band and/or changes in a same direction as the last adjustment that was performed with the first control regime. The first control regime can be a feedback-based adjustment to the component. The second control regime can be utilized to control changes within the hysteresis band. The second control regime can use open-loop based adjustments to the component.
    Type: Grant
    Filed: April 1, 2009
    Date of Patent: November 29, 2011
    Assignee: Liebert Corporation
    Inventor: Ian Spearing
  • Publication number: 20110284695
    Abstract: This device comprises an electromagnetic coil (3) in which there is able to slide a piston (6) which has at least a portion made of a material having paramagnetic susceptibility and which is placed in contact with the mechanical member when the drive device (1) is in the rest state. Electrical energy supply means are provided in order to store electrical energy and to abruptly release this energy into the coil and thus apply the high-energy magnetic movement pulse to the mechanical member. According to the invention, the piston (1) comprises a stack (9) of blocks (11, 12) which are made alternately from the material having paramagnetic susceptibility and an insulating material; and the electrical energy supply means are provided in order to allow the energy to be applied to the coil in the form of a series of electrical pulses which appear as the piston (6) moves.
    Type: Application
    Filed: August 22, 2008
    Publication date: November 24, 2011
    Applicants: INSTITUT FRANCO-ALLEMAND de RECHERCHES de SAINT-LOUIS, ALKAN
    Inventors: Jean-Jacques Derksema, Klaus Sterzelmeier
  • Patent number: 8044615
    Abstract: 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. The method for controlling, as an AC linear motor set, a plurality of AC linear motors of identical specifications which are connected to each other, includes the steps of firmly connecting the AC linear motors in such a manner that pole pitches of movers of the AC linear motors and pole intervals of adjacent movers are identical; and setting any one of the AC linear motors to be a master AC linear motor and using a command signal generated based on a feedback signal of the master AC linear motor and current difference information obtained by comparing phase current of the master AC linear motor with phase current of another AC linear motor to control the AC linear motor set.
    Type: Grant
    Filed: September 27, 2007
    Date of Patent: October 25, 2011
    Assignee: THK Co., Ltd.
    Inventors: Kazuo Shoda, Yoshifumi Nagato
  • Patent number: 8040082
    Abstract: A linear actuator includes a spindle nut, where the spindle nut and the spindle between a first and a second point, indicating the length of stroke, can move axially in proportion to each other, depending on whether the spindle or the spindle nut is being driven around via the transmission, and where the position is determined with incremental position sensors, such as at least two Hall sensors or Reed-switches. For determining the position an initiating procedure, where the nut/spindle is moved from a first point on the spindle/nut to a second point on the spindle nut is carried out, and that the number of pulses from the incremental position sensors appearing by it are registered as a measurement for the length of stroke, and the position is subsequently determined in relation to that. It is noted that the control is active before, during and after the operation of the motor.
    Type: Grant
    Filed: May 14, 2007
    Date of Patent: October 18, 2011
    Assignee: Linak A/S
    Inventor: Jeppe Bastholm
  • Patent number: 8035323
    Abstract: 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.
    Type: Grant
    Filed: August 3, 2006
    Date of Patent: October 11, 2011
    Assignee: Texchange Limited
    Inventors: Rupert John Cruise, Christopher Roger Lines
  • Patent number: 8030862
    Abstract: A method for applying power to an electronically commutated motor (ECM) is described. The method includes connecting an AC voltage source to an input of a rectification circuit, connecting a DC voltage source to an output of the rectification circuit, and electrically connecting the DC voltage source and rectification circuit output to operational components of the ECM. The DC voltage source is capable of providing a voltage equal to or greater than a rectified voltage originating from the AC voltage source, and the DC voltage source is connected in parallel with the output of the rectification circuit.
    Type: Grant
    Filed: March 8, 2007
    Date of Patent: October 4, 2011
    Assignee: RBC Manufacturing Corporation
    Inventor: William A. Archer
  • Patent number: 8026688
    Abstract: 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 (fd1?) lower than a resonance frequency (fr) of the electromechanical transducer element and lower than a frequency (fd1) that maximizes moving velocity of the movable member and sticking elimination pattern voltage having a frequency lower than the frequency (fd1?) of the drive operation pattern voltage and in vicinity of a frequency (fd2) that maximizes thrust acting on the movable member.
    Type: Grant
    Filed: April 10, 2007
    Date of Patent: September 27, 2011
    Assignee: Konica Minolta Opto, Inc.
    Inventors: Ryuichi Yoshida, Hirohisa Sueyoshi, Satoshi Shinke, Shinichi Yamamoto
  • Patent number: 8013547
    Abstract: 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.
    Type: Grant
    Filed: May 8, 2007
    Date of Patent: September 6, 2011
    Assignee: Siemens Aktiengesellschaft
    Inventor: Markus Engel
  • Publication number: 20110210686
    Abstract: 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 transver
    Type: Application
    Filed: November 10, 2009
    Publication date: September 1, 2011
    Inventor: Chanty Sengchanh
  • Patent number: 7994742
    Abstract: A position sensing system includes a member movable along a path, the member having an elongated magnet extending along the path, the magnetic field orientation of the elongated magnet being at an angle with respect to the path. A sensor determines a position of the member along the path based on a measurement of a magnetic field generated by the elongated magnet.
    Type: Grant
    Filed: March 25, 2008
    Date of Patent: August 9, 2011
    Assignee: Bose Corporation
    Inventor: Richard F. O'Day
  • Patent number: 7990084
    Abstract: 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.
    Type: Grant
    Filed: June 3, 2009
    Date of Patent: August 2, 2011
    Assignee: Korea Institute of Science and Technology
    Inventors: Seung-Jong Kim, Jong Min Lee, Woo Yeon Kim
  • Publication number: 20110175555
    Abstract: 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.
    Type: Application
    Filed: January 19, 2011
    Publication date: July 21, 2011
    Applicant: Robert Bosch GMBH
    Inventors: Uwe Daemmrich, Guido Kalbas
  • Patent number: 7982417
    Abstract: A stage unit includes the following elements. A stator includes a first coil array in which first coils extending in the x direction are arranged in the y direction, a second coil array in which second coils extending in the x direction are arranged in the y direction and which is located next to the first coil array in the x direction, and a third coil array in which third coils extending in the y direction are arranged in the x direction and which covers the first and second coil arrays. A movable member moves above the stator. A controller controls driving of the movable member by allowing current amplifiers to supply current to the coils included in the first, second, and third coil arrays. A switch is capable of connecting the first coil to the second coil.
    Type: Grant
    Filed: April 8, 2009
    Date of Patent: July 19, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventor: Shinji Ohishi
  • Patent number: 7977897
    Abstract: The invention relates to an apparatus and to a method for controlling or regulating the deflection of micromechanically manufactured deflectable elements which, driven electrostatically, are deflected in an oscillating manner. It is the object of the invention to provide a possibility with which a much larger deflection range can be utilized and in so doing the required voltage potential difference for the electrostatic drive of a deflection can be kept small and the occurrence of the pull-in effect can be avoided. In accordance with the invention, a deflectable element is present which is held at a frame element by at least one spring element and which can be deflected using an electrostatic drive. The deflection can be achieved by means of at least one counter-electrode and the deflectable element usable as an electrode.
    Type: Grant
    Filed: October 1, 2008
    Date of Patent: July 12, 2011
    Assignee: Fraunhofer-Gesellschaft zur Forderung der Angewandten Forschung E.V.
    Inventor: Harald Schenk
  • Publication number: 20110163769
    Abstract: Systems for and methods of determining at least one mid-stroke position of an active material actuated load by causing a stress induced rapid change in electrical resistance within the active material element, or modifying an ancillary circuit, when the load is at the mid-stroke position(s).
    Type: Application
    Filed: March 13, 2011
    Publication date: July 7, 2011
    Inventors: Guillermo A. Herrera, Xiujie Gao, Nancy L. Johnson, Alan L. Browne, Christopher P. Henry, Andrew C. Keefe, Geoffrey P. Mc Knight, Sloan Smith
  • Patent number: 7975314
    Abstract: There is provided a scanning probe microscope that allows active damping to be advantageously carried out. A Z scan control section functions as a driving control section to control a Z scanner that is a controlled object. Driving control is performed by supplying the controlled object with a driving signal processed by an adjustment function. The adjustment function adjusts the driving signal by using a simulated transfer function that simulates an actual transfer function indicative of an actual frequency characteristic of the controlled object so that executing processing of the simulated transfer function on the adjusted driving signal results in decrease of vibration of an output signal from the simulated transfer function.
    Type: Grant
    Filed: July 27, 2007
    Date of Patent: July 5, 2011
    Assignee: National University Corporation Kanazawa University
    Inventor: Toshio Ando
  • Publication number: 20110156619
    Abstract: 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.
    Type: Application
    Filed: August 21, 2009
    Publication date: June 30, 2011
    Applicant: THK CO., LTD.
    Inventor: Yuki Nomura
  • Patent number: 7969109
    Abstract: An electric actuator includes a motion conversion mechanism and a position detector. The motion conversion mechanism converts rotation of a rotary shaft of a motor into linear motion of an output shaft. The position detector detects a permanent magnet M, which moves integrally with the output shaft. A motor control portion controls the motor based on commands from a host command unit. A control program for controlling the motor includes, as control modes, six fluid pressure cylinder modes, according to which the motor is controlled. Specifically, each of the control modes corresponds to one of the cases where the fluid pressure cylinder is controlled by three solenoid valves, or a two-position single solenoid valve, a two-position double solenoid valve, and a three-position double solenoid valve. The motor is controlled according to the selected control mode.
    Type: Grant
    Filed: December 16, 2008
    Date of Patent: June 28, 2011
    Assignee: CKD Corporation
    Inventors: Shuzo Masuo, Tsuyoshi Kanada
  • Patent number: 7969103
    Abstract: 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.
    Type: Grant
    Filed: May 14, 2008
    Date of Patent: June 28, 2011
    Assignee: Electro Standards Laboratories
    Inventor: Raymond B. Sepe, Jr.
  • Publication number: 20110109252
    Abstract: 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.
    Type: Application
    Filed: October 15, 2010
    Publication date: May 12, 2011
    Applicant: YAMAHA HATSUDOKI KABUSHIKI KAISHA
    Inventor: Katsuyuki TAKAGI
  • Publication number: 20110101896
    Abstract: 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.
    Type: Application
    Filed: January 10, 2011
    Publication date: May 5, 2011
    Applicant: KABUSHIKI KAISHA YASKAWA DENKI
    Inventors: Toru SHIKAYAMA, Katsutoshi Yamanaka
  • Patent number: 7932684
    Abstract: To determine the relative position of movable portions of an assembly, a first magnetic device is coupled to a first portion of the assembly. The first magnetic device has a sensing surface with a number of magnetic poles that provide a magnetization state transition location. An absolute position sensor with a two-state output is coupled to the assembly adjacent the first magnetic device. The output state changes when a magnetization state transition of the first magnetic device moves past the absolute position sensor. A second magnetic device is coupled to the assembly. The second magnetic device creates a cyclically-varying magnetic field proximate its sensing surface. An incremental position sensor is coupled to the assembly adjacent the second magnetic device, and has an output that varies continuously relative to magnetic field angle over at least a portion of one cycle of the cyclically-varying magnetic field of the second magnetic device.
    Type: Grant
    Filed: March 25, 2010
    Date of Patent: April 26, 2011
    Assignee: Bose Corporation
    Inventors: Richard O'Day, Antonio Sangermano, II
  • Publication number: 20110088643
    Abstract: In a valve drive train device, in particular for a valve drive of an internal combustion engine, with a switching unit comprising an actuator with a solenoid unit and with a control unit for monitoring switching operations of the switching unit provided for switching an axially displaceable cam element by means of a switch gate, the control unit for monitoring the switching unit is taking into account at least one characteristic value of a voltage integral over a voltage which is induced in a coil of the switching unit during the switching operation and is adjusting the value with respect to a characteristic limit value stored in the control unit.
    Type: Application
    Filed: November 5, 2010
    Publication date: April 21, 2011
    Inventors: Matthias Gregor, Richard Jakobi
  • Publication number: 20110080123
    Abstract: 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.
    Type: Application
    Filed: December 15, 2010
    Publication date: April 7, 2011
    Inventors: James J. Sheahan, JR., Charles E. Morris, Paul Kersens
  • Patent number: 7919938
    Abstract: An actuator arrangement comprises a plurality of linearly extendable actuators arranged to be driven by a common electrically driven motor, each actuator, being provided with limit stops to limit extension and/or retraction thereof, wherein the limit stops of the actuators are positioned such that a first one of the actuators has a smaller range of permitted extension than at least a second one of the actuators.
    Type: Grant
    Filed: April 3, 2008
    Date of Patent: April 5, 2011
    Assignee: Goodrich Actuation Systems Limited
    Inventors: John Herbert Harvey, Stephen Harlow Davies
  • Publication number: 20110062901
    Abstract: 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.
    Type: Application
    Filed: July 30, 2008
    Publication date: March 17, 2011
    Applicant: Dorma GmbH + Co. KG
    Inventor: Sven Busch
  • Patent number: 7906930
    Abstract: The brushless electric machine includes a first drive member (30U) having a plurality of permanent magnets (32U); a second drive member (10) having a plurality of electromagnetic coils and capable of movement relative to the first drive member (30U); and a third drive member (30L) disposed at the opposite side from the first drive member (30U) with the second drive member (10) therebetween, and having a fixed relative positional relationship with respect to the first drive member (30U). The second drive member (10) has magnetic sensors (40A, 40B) for detecting relative position of the first and second drive members; and a control circuit for carrying out control of the brushless electric machine utilizing the output signals of the magnetic sensors.
    Type: Grant
    Filed: April 17, 2008
    Date of Patent: March 15, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Kesatoshi Takeuchi, Mamoru Sugimoto, Yojiro Okakura
  • Patent number: 7898121
    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.
    Type: Grant
    Filed: September 21, 2006
    Date of Patent: March 1, 2011
    Assignee: Ricardo UK Ltd
    Inventors: Keith Ramsay, Andrew Turner, Richard E. Clark
  • Patent number: 7888893
    Abstract: 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.
    Type: Grant
    Filed: March 2, 2010
    Date of Patent: February 15, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Hirokazu Nagura, Hiromi Inaba, Toshifumi Yoshikawa, Hironori Ohashi, Yuri Takano, Masaki Sugiura
  • Publication number: 20110029197
    Abstract: It is a task of the invention to obtain a favorable thrust force characteristic with respect to a stroke of an actuator even if the actuator is used in a thrust force control. To solve the task, in the present invention, a linear motor type electrically-powered actuator AC with a linear motor 3 as a drive section is drivingly controlled. With a basic thrust force variation with respect to the stroke in a non-excitation state as a basis, a thrust force command Fc is used to correct a phase of the basic thrust force variation and a magnitude thereof to determine a compensation quantity which corresponds to the thrust force variation with respect to the stroke.
    Type: Application
    Filed: March 24, 2009
    Publication date: February 3, 2011
    Inventors: Kenya Uenuma, Tadashi Tamasho, Masatsugu Yokote, Takuma Suzuki, Yosuke Yamaguchi, Masato Takehi
  • Patent number: 7872437
    Abstract: A method for position and/or speed control of a linear drive utilizing a converter having a control unit and being coupled to a motor of the linear drive. The method includes determining, in a sensor-free manner, a motor position, generating a motor position signal, generating an acceleration signal utilizing an MEMS accelerometer provided in the control unit and arranged on a moving part of the linear drive, mathematically converting the motor position signal and the acceleration signal to a speed signal, and utilizing the speed signal to control the linear drive.
    Type: Grant
    Filed: May 24, 2006
    Date of Patent: January 18, 2011
    Assignee: Wittmann Kunststoffgeraete GmbH
    Inventor: Tomas Kalender
  • Patent number: 7868565
    Abstract: A method of selectively utilizing a set of linear actuator motors for an application includes providing a plurality of linear actuator motors numbered from 1 to N including a box shaped housing with respective lengths between a first end-plate and a second end-plate and respective hollow shafts. Each hollow shaft includes an extended portion out of either the first end-plate or the second end-plate and configured to receive a nut including a tube part integrally connected with a flat-end part. The nut is configured to be able to mate in a common manner to any of the plurality of linear actuator motors. The method further includes testing any of the plurality of linear actuator motors including the nut for the application, wherein the nut is detached from one linear actuator motor to reattach with another linear actuator motor.
    Type: Grant
    Filed: June 20, 2008
    Date of Patent: January 11, 2011
    Assignees: Minebea Co., Ltd., Minebea Motor Manufacturing Corporation
    Inventors: Yoshio Sato, Takeshi Yoshizawa
  • Patent number: 7868566
    Abstract: A method for operating a linear compressor including a linear drive with a stator and a rotor configured for displacement by a magnetic field of the stator against a spring force, and a compression chamber which is delimited by a displaceable piston coupled to the rotor during the operation of which an alternating current is applied to the stator in order to drive the rotor in an reciprocatingly, the method including the steps of applying, prior to operation, a direct current with a first polarity to the stator in order to displace the rotor from a rest position, measuring a first end position attained by the rotor under the action of the direct current, and controlling, during operation, the intensity of the alternating current with which the stator is excited in a manner wherein the rotor does not reach the first end position or reaches it at a reduced speed.
    Type: Grant
    Filed: January 25, 2007
    Date of Patent: January 11, 2011
    Assignee: BSH Bosch und Siemens Hausgeraete GmbH
    Inventors: Mario Bechtold, Johannes Reinschke
  • Patent number: 7852022
    Abstract: A control apparatus for an electric car, including a power converter which feeds AC power of variable voltage and variable frequency to a primary side member of a linear electromagnetic actuator, voltage command means for giving a command of a voltage which is fed to the linear electromagnetic actuator, current detection means for detecting current information which flows between the power converter and the linear electromagnetic actuator, and motor constant calculation means for calculating a motor constant of the linear electromagnetic actuator on the basis of the voltage information Vu given by the voltage command means and the current information Iu detected by the current detection means.
    Type: Grant
    Filed: June 29, 2007
    Date of Patent: December 14, 2010
    Assignee: Mitsubishi Electric Corporation
    Inventors: Masaki Kono, Tsuneyasu Kakizaki
  • Publication number: 20100295488
    Abstract: A vibratory driving device 1 comprising a shaft-like driving member 8, a electromechanical transducer 6 which can incline the driving member 8 and which also can displace the driving member 8 in the axial direction of the driving member, a movable member 9 which slidably engages on the driving member 8, a driving circuit 3 which can apply to the electromechanical transducer 6 a frictional driving voltage displacing the driving member 8 back and forth with a speed varying asymmetrically in the axial direction to displace slidingly the movable member 9 with respect to the driving member 8 and a periodical inclination driving voltage inclinatory oscillating the driving member 8, a resonance frequency meter which measures a resonance frequency of the inclining oscillation of the driving member 8, and a position estimator which estimates a position of the movable member 9 based on the resonance frequency.
    Type: Application
    Filed: May 18, 2010
    Publication date: November 25, 2010
    Inventor: Kazuhiro SHIBATANI
  • Publication number: 20100294161
    Abstract: A cable transportation system has a pull cable; at least one transportation unit moving along a given path and connectable selectively to the pull cable by a coupling device; at least one passenger station where the transportation unit is detached from the pull cable; and an auxiliary drive device having a linear electric motor extending along a portion of the given path to move the transportation unit along the passenger station.
    Type: Application
    Filed: August 4, 2008
    Publication date: November 25, 2010
    Applicant: Rolic Invest S.AR.L.
    Inventors: Federico Bavaresco, Peter Leimstadtner
  • Patent number: 7839101
    Abstract: 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.
    Type: Grant
    Filed: May 2, 2008
    Date of Patent: November 23, 2010
    Assignee: Board of Regents, The University of Texas System
    Inventors: Haidong Yu, Babak Fahimi
  • Publication number: 20100292878
    Abstract: [Problem] A drive control apparatus for an electric car as can correct a synchronizing frequency without employing beacons, is proposed. [Means for Resolution] Wheel-diameter correction information output means includes wheel-diameter information calculation means for calculating wheel-diameter calculation information expressive of a wheel diameter of an electric car, on the basis of two-phase current information. The wheel-diameter correction information output means also includes selection output means. The selection output means selects a wheel-diameter data output WD1, the wheel-diameter calculation information WD2 based on the wheel-diameter calculation means, or wheel-diameter default information WD0, and it outputs wheel-diameter correction information WD. Synchronizing-frequency calculation means 37 outputs synchronizing frequency information FM on the basis of axle rotational-frequency information FR and the wheel-diameter correction information WD.
    Type: Application
    Filed: April 17, 2006
    Publication date: November 18, 2010
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Hiroyuki Kayano, Tsuneyasu Kakizaki