Patents by Inventor Hiroyuki Mikami

Hiroyuki Mikami 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).

  • Patent number: 7902713
    Abstract: A self-starting type permanent magnet synchronous motor comprises a stator and a rotor. The rotor comprises a rotor core having a plurality of slots provided in an outer periphery thereof and a cage winding comprising conductive bars embedded in the slots and conductive end rings that short-circuit the conductive bars on both end faces of the bars in an axial direction thereof. The rotor core comprises at least one magnet insertion hole arranged on an inner peripheral side from the slots, and at least one permanent magnet embedded in the at least one magnet insertion hole. When a pole center axis is denoted as a d-axis and an axis deviating from the pole center axis by an electrical angle 90° is denoted as a q-axis, a flux content generated by the cage winding during start-up becomes maximal in the vicinity of and on one of the d-axis and the q-axis.
    Type: Grant
    Filed: December 17, 2008
    Date of Patent: March 8, 2011
    Assignee: Hitachi Appliances, Inc.
    Inventors: Satoshi Kikuchi, Hiroyuki Mikami, Akeshi Takahashi, Tomio Yoshikawa, Keiji Tanaka, Masashi Miyake, Baiying Huang, Masaru Ohtahara, Kenji Tojo, Hideyuki Kumakura
  • Publication number: 20110030419
    Abstract: There is provided a self-starting permanent magnet synchronous motor in which a center axis of magnetic poles of a rotor is assumed to be a d axis, an axis deviated from the magnetic pole center axis by an electric angle of 90 degrees is assumed to be a q axis, at least two or more starting bars which are arranged near the d axis are arranged on a bore side of the bars near the q axis and are arranged in parallel with the q axis, so that a stable starting torque can be generated irrespective of a generating position of a stator magnetic flux which changes due to applying timing of a power source and a phase of a voltage, and a vibration/noises at the time of a stationary operation can be reduced.
    Type: Application
    Filed: August 5, 2010
    Publication date: February 10, 2011
    Inventors: Satoshi KIKUCHI, Hiroyuki MIKAMI, Tomio YOSHIKAWA, Baiying HUANG, Hideyuki KUMAKURA
  • Patent number: 7880358
    Abstract: A permanent magnet rotating electric machine has a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof. The rotor core is fixed on a rotary shaft rotating inside the stator, and one magnetic pole is constituted by each group of three or more of the magnets. A total angle occupied by the group of magnets constituting one magnetic pole is in the range of 150 to 165 degrees in terms of an electrical angle.
    Type: Grant
    Filed: May 26, 2010
    Date of Patent: February 1, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Tsukasa Taniguchi, Hiroyuki Mikami, Satoshi Kikuchi, Fumio Jyoraku, Hideyuki Harada
  • Patent number: 7847456
    Abstract: A permanent magnet electrical rotating machine having a permanent magnet rotor and a stator, wherein: a plurality of permanent magnets are disposed in a rotor iron core of the permanent magnet rotor along a periphery of the rotor iron core, polarities thereof being alternately changed; a cooling airflow channel is formed between each pair of adjacent opposite poles on the rotor iron core; and the cooling airflow channel has an approximately trapezoidal shape on an outer periphery side of the rotor iron core; and extends from an end on a central side in a radial direction of the approximately trapezoidal shape to a radial center.
    Type: Grant
    Filed: April 5, 2010
    Date of Patent: December 7, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Daisuke Kori, Tetsuo Fujigaki, Shuji Aizawa, Motonobu Iizuka, Yasushi Iwai, Hiroyuki Mikami, Mamoru Kimura
  • Publication number: 20100231078
    Abstract: A permanent magnet rotating electric machine has a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof. The rotor core is fixed on a rotary shaft rotating inside the stator, and one magnetic pole is constituted by each group of three or more of the magnets. A total angle occupied by the group of magnets constituting one magnetic pole is in the range of 150 to 165 degrees in terms of an electrical angle.
    Type: Application
    Filed: May 26, 2010
    Publication date: September 16, 2010
    Applicant: Hitachi, LTD
    Inventors: Tsukasa TANIGUCHI, Hiroyuki Mikami, Satoshi Kikuchi, Fumio Jiyoraku, Hideyuki Harada
  • Publication number: 20100194221
    Abstract: A permanent magnet electrical rotating machine having a permanent magnet rotor and a stator, wherein: a plurality of permanent magnets are disposed in a rotor iron core of the permanent magnet rotor along a periphery of the rotor iron core, polarities thereof being alternately changed; a cooling airflow channel is formed between each pair of adjacent opposite poles on the rotor iron core; and the cooling airflow channel has an approximately trapezoidal shape on an outer periphery side of the rotor iron core; and extends from an end on a central side in a radial direction of the approximately trapezoidal shape to a radial center.
    Type: Application
    Filed: April 5, 2010
    Publication date: August 5, 2010
    Inventors: Daisuke KORI, Tetsuo Fujigaki, Shuji Aizawa, Motonobu Iizuka, Yasushi Iwai, Hiroyuki Mikami, Mamoru Kimura
  • Patent number: 7768171
    Abstract: A permanent magnet rotating electric machine has a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof. The rotor core is fixed on a rotary shaft rotating inside the stator, and one magnetic pole is constituted by each group of three or more of the magnets. A total angle occupied by the group of magnets constituting one magnetic pole is in the range of 150 to 165 degrees in terms of an electrical angle.
    Type: Grant
    Filed: July 8, 2008
    Date of Patent: August 3, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Tsukasa Taniguchi, Hiroyuki Mikami, Satoshi Kikuchi, Fumio Jyoraku, Hideyuki Harada
  • Publication number: 20100176682
    Abstract: A permanent magnet type rotary electric machine has a rotor having a rotor core and permanent magnets buried into the rotor core by being incorporated into respective permanent magnet slots. The permanent magnet slot per one pole is divided at least into four slots along an outer circumferential direction in the rotor core, and in respective rest core-portions between adjacent divided permanent magnet slots in the rotor core, a width of a first rest core-portion at the middle of each pole and a width of a second rest core-portion between adjacent poles of different polarities are formed larger than that of the others.
    Type: Application
    Filed: January 8, 2010
    Publication date: July 15, 2010
    Applicant: HITACHI, LTD.
    Inventors: Daisuke Kori, Hiroyuki Mikami, Seikichi Masuda, Mamoru Kimura
  • Publication number: 20100026008
    Abstract: A synchronous generator 1 including a rotor having a field winding placed in the slots thereof and a stator having an armature winding placed in the slots thereof, wherein the value of the number of slots per two poles in stator minus the number of slots per two poles in rotor is equal to or greater than +9, or equal to or smaller than ?9.
    Type: Application
    Filed: July 22, 2009
    Publication date: February 4, 2010
    Applicant: HITACHI, LTD.
    Inventors: Masanori SAWAHATA, Kazuo NISHIHAMA, Hiroyuki MIKAMI, Tetsuo FUJIGAKI, Motonobu IIZUKA, Shuji MIZUTANI
  • Publication number: 20090322175
    Abstract: A rotor is deployed such that the rotor becomes coaxially rotatable with a stator. A shaft is fixed onto the axis of a rotor iron-core. 1-pole constituting magnet slots are deployed into V-character pattern along an outer circumference portion of the rotor iron-core. Permanent magnets are embedded into the magnet slots. For the 1 pole, the 2 pieces of same-polarity permanent magnets are embedded into the V-character pattern. The configuration of each embedded permanent magnet is designed as follows: From the thickness of the permanent-magnet edge portion on the inner-diameter side of the rotor iron-core, which becomes the center of the V-character pattern, the thickness of the permanent magnet gradually increases toward the outer-diameter side of the rotor iron-core, which become the right and left edge portions of the V-character pattern. Simultaneously, curved lines are provided on both edge portions of the permanent magnet.
    Type: Application
    Filed: June 22, 2009
    Publication date: December 31, 2009
    Applicant: HITACHI, LTD.
    Inventors: Daisuke KORI, Mamoru KIMURA, Hiroyuki MIKAMI, Seikichi MASUDA, Masayasu FUJIEDA
  • Publication number: 20090267428
    Abstract: A rotating electrical machine includes: a rotor comprising a rotor core and a field winding wound round the rotor core; and a stator comprising a stator core and a stator winding wound round the stator core. The stator is arranged in opposition to the rotor with a predetermined spacing therebetween. the stator core is formed by punching a split piece, which comprises teeth for insertion of the stator winding thereinto and a core back on an outer periphery thereof, from a magnetic steel sheet, and laminating a plurality of those circular configurations in an axial direction, in which a plurality of the split pieces are arranged in a circle in a circumferential direction. The stator core has magnetic steel sheets, which are different in magnetic permeability in a diametrical direction, laminated at an axial end region of and in an axial central region of the stator core.
    Type: Application
    Filed: April 23, 2009
    Publication date: October 29, 2009
    Inventors: Akihito NAKAHARA, Hiroyuki Mikami, Kazumasa Ide, Kazuhiko Takahashi, Kenichi Hattori
  • Publication number: 20090200885
    Abstract: The present invention provides a permanent magnet that a fluorine compound is formed on the surfaces of Fe-based magnetic particles, and a recoil permeability is determined in a range of 1.05 to 1.30 by controlling an iron concentration in the fluorine compound to a range of 1 to 50% to reduce a loss due to magnetization rotation, thereby remedying reduction of a residual magnetic flux density and degradation of steady-state characteristics.
    Type: Application
    Filed: December 23, 2008
    Publication date: August 13, 2009
    Inventors: Satoshi Kikuchi, Yuuichi Satsuu, Matahiro Komuro, Hiroyuki Mikami, Akeshi Takahashi
  • Publication number: 20090160285
    Abstract: A self-starting type permanent magnet synchronous motor comprises a stator and a rotor. The rotor comprises a rotor core having a plurality of slots provided in an outer periphery thereof and a cage winding comprising conductive bars embedded in the slots and conductive end rings that short-circuit the conductive bars on both end faces of the bars in an axial direction thereof. The rotor core comprises at least one magnet insertion hole arranged on an inner peripheral side from the slots, and at least one permanent magnet embedded in the at least one magnet insertion hole. When a pole center axis is denoted as a d-axis and an axis deviating from the pole center axis by an electrical angle 90° is denoted as a q-axis, a flux content generated by the cage winding during start-up becomes maximal in the vicinity of and on one of the d-axis and the q-axis.
    Type: Application
    Filed: December 17, 2008
    Publication date: June 25, 2009
    Inventors: Satoshi Kikuchi, Hiroyuki Mikami, Akeshi Takahashi, Tomio Yoshikawa, Keiji Tanaka, Masashi Miyake, Baiying Huang, Masaru Ohtahara, Kenji Tojo, Hideyuki Kumakura
  • Publication number: 20090096317
    Abstract: There is provided a rotating machine including a stator and a rotor, in which the inner side surface (facing the stator) of the axial end structures of the stator is provided with grooves filled with an electrically nonconductive material.
    Type: Application
    Filed: October 14, 2008
    Publication date: April 16, 2009
    Inventors: Manabu Sasaki, Hiroyuki Mikami, Tadaharu Kishibe
  • Publication number: 20090015090
    Abstract: Movement of magnets due to centrifugal force is restricted. In a permanent magnet rotating electrical machine 100 having a stator 1 and a rotor core 5 provided with a plurality of permanent magnets 3 inserted in an outer circumferential portion of the rotor 5, each permanent magnet 3 has inclined surfaces on the outer circumferential side of the rotor 2 and the thinnest portions of the inclined surfaces are adjacent to permanent magnets of the opposite polarity. Further, each magnet 3 has a convex-shaped cross section and is divided into two magnet segments 3, 3. A magnetic pole bridge 15 is formed at the boundary of the permanent magnet segments 3, 3. Thus, movement of the permanent magnet segments 3, 3 due to centrifugal force is firmly restricted, and the peeling off of the rotor core 5 and the permanent magnet segments 3, 3 from each other is prevented.
    Type: Application
    Filed: July 10, 2008
    Publication date: January 15, 2009
    Inventors: Mamoru Kimura, Daisuke Kori, Hiroyuki Mikami, Seikichi Masuda, Masayasu Fujieda
  • Publication number: 20080278017
    Abstract: A permanent magnet rotating electric machine has a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof. The rotor core is fixed on a rotary shaft rotating inside the stator, and one magnetic pole is constituted by each group of three or more of the magnets. A total angle occupied by the group of magnets constituting one magnetic pole is in the range of 150 to 165 degrees in terms of an electrical angle.
    Type: Application
    Filed: July 8, 2008
    Publication date: November 13, 2008
    Applicant: Hitachi, LTD
    Inventors: Tsukasa TANIGUCHI, Hiroyuki Mikami, Satoshi Kikuchi, Fumio Jyoraku, Hideyuki Harada
  • Publication number: 20080238237
    Abstract: An induction machine has a stator and rotor. The stator comprises teeth and slots and stator winding disposed in the slots. The rotor comprises a rotor core having teeth and slots and a rotor-conductor disposed in the rotor slots. Both of the stator core and rotor core are made of laminated steel sheets, and the teeth and slots made of steel sheets are formed by etching.
    Type: Application
    Filed: February 6, 2008
    Publication date: October 2, 2008
    Inventors: Kazuo Nishihama, Teruyoshi Abe, Yoshihisa Ishikawa, Hiroyuki Mikami
  • Publication number: 20080238235
    Abstract: A self-starting permanent magnet synchronous motor which demonstrates satisfactory acceleration performance even at a reduced supply voltage or with an increased load torque, and a compressor using the same. The motor comprises a stator having a stator winding and a rotor having a cage winding and a permanent magnet on the rotor core. The torque component generated by the cage winding is maximal at 1 in the slip range of 0 to 1.
    Type: Application
    Filed: January 25, 2008
    Publication date: October 2, 2008
    Inventors: Akeshi TAKAHASHI, Satoshi Kikuchi, Hiroyuki Mikami, Kazuo Nishihama, Tomio Yoshikawa, Baiying Huang
  • Patent number: 7417348
    Abstract: In the prior art in which permanent magnets are regularly arranged over the whole circumference of a rotor core, a satisfactory magnetic flux distribution is hard to obtain, and the cogging torque and the distortion factor of the induced electromotive force waveform are large, whereby characteristics of a rotating electric machine are poor. Also, because the permanent magnets are arranged over the whole circumference, a large number of permanent magnets are required and cost reduction is difficult. A permanent magnet rotating electric-machine of the invention comprises a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof, the rotor core being fixed on a rotary shaft rotating inside the stator, and in which one magnetic pole is constituted by each group of three or more of the magnets.
    Type: Grant
    Filed: August 8, 2003
    Date of Patent: August 26, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Tsukasa Taniguchi, Hiroyuki Mikami, Satoshi Kikuchi, Fumio Jyoraku, Hideyuki Harada
  • Publication number: 20080129129
    Abstract: A permanent magnet electrical rotating machine having a permanent magnet rotor and a stator, wherein: a plurality of permanent magnets are disposed in a rotor iron core of the permanent magnet rotor along a periphery of the rotor iron core, polarities thereof being alternately changed; a cooling airflow channel is formed between each pair of adjacent opposite poles on the rotor iron core; and the cooling airflow channel has an approximately trapezoidal shape on an outer periphery side of the rotor iron core; and extends from an end on a central side in a radial direction of the approximately trapezoidal shape to a radial center.
    Type: Application
    Filed: November 21, 2007
    Publication date: June 5, 2008
    Inventors: Daisuke Kori, Tetsuo Fujigaki, Shuji Aizawa, Motonobu Iizuka, Yasushi Iwai, Hiroyuki Mikami, Mamoru Kimura