Patents by Inventor Yu HIROTANI

Yu HIROTANI has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20160072416
    Abstract: [Object] To effectively improve torque of a motor, the maximum rotation rate in driving with no load, and output at a high rotation rate, while suppressing torque ripple, noise, or vibration of the motor. [Solution] A brushless motor 301 has an armature iron core 310 wound with armature windings including plural winding sets 311 and 312 each of which includes multi-phase windings. Voltage application means 302 applies voltages to the plural winding sets. Control means 303 calculates a voltage command for the plural winding sets, and controls the voltage application means based on the voltage command. The control means 303 controls the voltage application means 302 so that induced voltages generated in the plural winding sets by rotation of the brushless motor have a trapezoidal waveform and a phase difference between the voltages for the plural winding sets becomes a value that reduces torque ripple caused by the induced voltages.
    Type: Application
    Filed: February 12, 2013
    Publication date: March 10, 2016
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yu HIROTANI, Yuji TAKIZAWA, Tatsuya MORI, Isao KEZOBO, Yoshihiko KIMPARA
  • Publication number: 20160056696
    Abstract: A stator core includes an inner ring core composed of a plurality of teeth arranged in the circumferential direction and a connection portion connecting inner circumferential portions of the plurality of teeth; and an outer ring core to be joined to an outer circumferential surface of the inner ring core. Slots of the stator core each have a circumferential direction width (a) on an inner circumference side smaller than a circumferential direction width (b) on an outer circumference side. A stator coil composed of conductive coils including a plurality of slot accommodated portions and a plurality of coil end portions connecting the slot accommodated portions is inserted and placed in the slots from an outer side in the radial direction of the inner ring core.
    Type: Application
    Filed: March 4, 2014
    Publication date: February 25, 2016
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Shinichi ITO, Sachiko KAWASAKI, Yu HIROTANI, Masatsugu NAKANO, Toyoaki UDO, Hiroyuki MATSUO
  • Publication number: 20160036281
    Abstract: A permanent magnet motor is provided in which, in flanges each provided in a plurality of teeth, lateral side portions of the flanges oppose to lateral side portions the flanges being provided in adjacent teeth and protruding in a circumferential direction of a stator core; when a height in the lateral side portion of the flanges in a radial direction of the stator core is defined as “h,” and the length of a magnetic air gap is defined as “g,” the relationship “1?h/g?2” is held; and also, when a circumferential distance between opposing faces of the flanges being adjacent to each other is defined as “a,” the relationship “a/g?0.2” is satisfied.
    Type: Application
    Filed: July 22, 2013
    Publication date: February 4, 2016
    Applicant: Mitsubishi Electric Corporation
    Inventors: Masatsugu NAKANO, Yu HIROTANI, Yuji TAKIZAWA, Satoru AKUTSU, Toyoaki UDO
  • Patent number: 9240707
    Abstract: A coil is configured so that: N conductor wires of wave windings each divided at at least two positions in a circumferential direction are provided in one of a plurality of slots; within a unit of the divided wave windings in which conduction is made, the N conductor wires are connected in one of series and parallel to each other at division positions located at substantially the same circumferential position of conductor-wire end portions; division units of the divided wave windings are connected in series to each other, and a total number of series turns of the series-connected division units of the each phase is a predetermined number of series turns, which does not exceed an upper limit value of a terminal voltage of the rotary electric machine; and the series-connected division units of the each phase have the same total number of series turns.
    Type: Grant
    Filed: September 12, 2012
    Date of Patent: January 19, 2016
    Assignee: Mitsubishi Electric Corporation
    Inventors: Ryuichi Takiguchi, Yuji Takizawa, Yu Hirotani, Satoru Akutsu, Masatsugu Nakano, Tetsuya Iwata
  • Publication number: 20150357892
    Abstract: To provide a permanent magnet type motor having reduced torque ripple, in which torque ripples for electric angle sixth order and twelfth order are both reduced with a small skew angle. Driving is performed such that phases of currents flowing in two sets of three-phase armature windings 26-1 and 26-2 are different from each other by 20 degrees to 40 degrees in electric angle. A rotor 11 is composed of m stages of rotor component units arranged in the axial direction. The m stages of rotor component units are skewed to have a stage-skew structure such that a skew angle ? (unit: degree) between the adjacent units satisfies 26/m???43.2/m (m is an integer equal to or greater than 2) in electric angle.
    Type: Application
    Filed: April 22, 2013
    Publication date: December 10, 2015
    Applicant: Mitsubishi Electric Corporation
    Inventors: Masatsugu NAKANO, Yu HIROTANI, Satoru AKUTSU, Toyoaki UDO, Yuji TAKIZAWA
  • Publication number: 20150333586
    Abstract: To obtain a permanent magnet type motor capable of securing controllability of a motor and utilizing reluctance torque. An armature winding is a plurality of sets of polyphase windings; the plurality of sets of the armature winding is supplied with current from each individual inverter; the rotor core is provided with permanent magnets on a surface portion thereof, the permanent magnets being circumferentially arranged and the adjacent permanent magnets having polarities opposite to each other; a protrusion portion is provided between the adjacent permanent magnets, the protrusion portion being provided in a protruding condition from the rotor core and being made of a magnetic substance; and a non-magnetic gap portion is interposed between the protrusion portion and the permanent magnet in a rotating shaft direction.
    Type: Application
    Filed: April 9, 2013
    Publication date: November 19, 2015
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yu HIROTANI, Minako IEFUJI, Yuji TAKIZAWA, Sachiko KAWASAKI, Masatsugu NAKANO, Toyoaki UDO, Satoru AKUTSU
  • Publication number: 20150280502
    Abstract: A multiplex multiphase winding AC motor includes an armature iron core provided with a plurality of teeth and a plurality of slots, an armature winding provided with two or more groups of multiphase windings that are wound around the teeth and are contained in the slots, a plurality of motor driving apparatuses independently connected with the two or more groups of multiphase windings, and a magnetic-field-pole iron core provided with a plurality of magnetic-field poles arranged in such a way as to face the armature iron core through a gap; in the magnetic-field-pole iron core, a plurality of magnetic resistance elements for impeding a magnetic-flux flow in the circumferential direction thereof are formed.
    Type: Application
    Filed: March 8, 2013
    Publication date: October 1, 2015
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yu Hirotani, Yuji Takizawa, Masatsugu Nakano, Satoru Akutsu, Toyoaki Udo
  • Publication number: 20140346910
    Abstract: In a permanent magnet type concentrated winding motor, the number of magnetic poles is M, a stator Sr has an N number of teeth T around which coils are concentratedly wound and which are circumferentially arranged at equal intervals, M is equal to (18±4)n and N is equal to 18n, an armature winding AW has an m number of parallel circuits, and a 1-phase circuit of the parallel circuits is configured to have a 6n/m number of coils connected in series with each other.
    Type: Application
    Filed: December 12, 2011
    Publication date: November 27, 2014
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Masatsugu Nakano, Satoru Akutsu, Yoshihito Asao, Yuji Takizawa, Yu Hirotani, Ryuichi Takiguchi
  • Publication number: 20140340015
    Abstract: The present invention provides a brushless motor in which the voltage utilization ratio can be increased and the torque and output of the motor can thereby be increased, and also provides a drive method for a brushless motor. The brushless motor includes an armature constituted by an armature core having armature windings of a plurality of phases, and a field pole constituted by a field pole core having a plurality of permanent magnets. A voltage, in which at least a 5th order harmonic component is superimposed on a 1st order fundamental wave of a voltage under predetermined phase difference condition and amplitude condition in order to increase a 1st order fundamental wave peak of the applied voltage over an applied voltage peak, is applied to the armature windings.
    Type: Application
    Filed: January 11, 2013
    Publication date: November 20, 2014
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yu Hirotani, Ryuichi Takiguchi, Yuji Takizawa, Tetsuya Kojima, Masatsugu Nakano, Satoru Akutsu
  • Patent number: 8829758
    Abstract: Provided is a rotary electric machine, including: a stator; and a rotor provided on the stator so as to be rotatable about a rotation shaft, in which the rotor includes, at an outer circumference thereof, magnetic poles arranged so as to have different polarities alternately, the magnetic poles being formed of a rotor core in which electromagnetic steel plates are stacked, the magnetic poles being excited by permanent magnets which are housed in gaps disposed at an outer circumferential part of the rotor core, and in which the rotor core includes, at an inner circumferential part thereof, in the same stack plane: a short circuit magnetic path connecting magnetic pole pieces which form the magnetic poles; and a protruding portion held in contact with the permanent magnets, which is positioned between magnetic pole pieces which are not connected to the short circuit magnetic path.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: September 9, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuji Takizawa, Yu Hirotani, Ryuichi Takiguchi, Hiroko Ueyama, Satoru Akutsu, Masatsugu Nakano, Tetsuya Iwata
  • Publication number: 20140191628
    Abstract: A permanent magnet motor in which electromagnetic excitation force of low spatial order is reduced, and influence of a magnetomotive force harmonic of a rotor and torque ripple is reduced. One set of armature windings receives current from a first inverter, and another set of armature windings receives current from a second inverter. Where a pole number of a rotor is M and the number of slots of a stator core is Q, M and Q satisfy M<Q and a greatest common divisor of M and Q is equal to or greater than 3. In the rotor, the iron core is located beyond a radius intermediate the maximum outer radius and the minimum inner radius of the permanent magnets. A phase difference between three-phase currents from the first and second inverters is in a range of electrical angles of 20 to 40 degrees.
    Type: Application
    Filed: December 23, 2011
    Publication date: July 10, 2014
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Masatsugu Nakano, Yoshihito Asao, Satoru Akutsu, Ryuichi Takiguchi, Yuji Takizawa, Yu Hirotani
  • Publication number: 20140145547
    Abstract: Provided is a permanent magnet motor that realizes reduction of both cogging torque and torque ripple, and also downsizing and weight reduction together with torque ripple reduction. When two sets of three-phase armature windings are defined such that a first armature winding 30-1 corresponds to U1 phase, V1 phase, and W1 phase and a second armature winding 30-2 corresponds to U2 phase, V2 phase, and W2 phase, U1 phase is provided in both of any adjacent slots of a plurality of slots 27, or at least one of U1 phase and U2 phase is provided in one of any adjacent slots 27, U1 phase, V1 phase, and W1 phase are shifted by an electric angle of 20° to 40° from U2 phase, V2 phase, and W2 phase upon driving, and a slot opening width Ws of a stator iron core 22 is set to satisfy Ws/(2?Rs/Ns)?0.15, where Rs is an inner radius of the stator iron core and Ns is a slot number of the stator iron core.
    Type: Application
    Filed: October 14, 2011
    Publication date: May 29, 2014
    Applicant: Mitsubishi Electric Corporation
    Inventors: Masatsugu Nakano, Satoru Akutsu, Yoshihito Asao, Yuji Takizawa, Yu Hirotani, Ryuichi Takiguchi
  • Publication number: 20130234555
    Abstract: Provided is a rotary electric machine, including: a stator; and a rotor provided on the stator so as to be rotatable about a rotation shaft, in which the rotor includes, at an outer circumference thereof, magnetic poles arranged so as to have different polarities alternately, the magnetic poles being formed of a rotor core in which electromagnetic steel plates are stacked, the magnetic poles being excited by permanent magnets which are housed in gaps disposed at an outer circumferential part of the rotor core, and in which the rotor core includes, at an inner circumferential part thereof, in the same stack plane: a short circuit magnetic path connecting magnetic pole pieces which form the magnetic poles; and a protruding portion held in contact with the permanent magnets, which is positioned between magnetic pole pieces which are not connected to the short circuit magnetic path.
    Type: Application
    Filed: September 13, 2012
    Publication date: September 12, 2013
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yuji TAKIZAWA, Yu HIROTANI, Ryuichi TAKIGUCHI, Hiroko UEYAMA, Satoru AKUTSU, Masatsugu NAKANO, Tetsuya IWATA
  • Publication number: 20130187510
    Abstract: A coil is configured so that: N conductor wires of wave windings each divided at at least two positions in a circumferential direction are provided in one of a plurality of slots; within a unit of the divided wave windings in which conduction is made, the N conductor wires are connected in one of series and parallel to each other at division positions located at substantially the same circumferential position of conductor-wire end portions; division units of the divided wave windings are connected in series to each other, and a total number of series turns of the series-connected division units of the each phase is a predetermined number of series turns, which does not exceed an upper limit value of a terminal voltage of the rotary electric machine; and the series-connected division units of the each phase have the same total number of series turns.
    Type: Application
    Filed: September 12, 2012
    Publication date: July 25, 2013
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Ryuichi TAKIGUCHI, Yuji TAKIZAWA, Yu HIROTANI, Satoru AKUTSU, Masatsugu NAKANO, Tetsuya IWATA