Patents by Inventor Shouichi Kawamata

Shouichi Kawamata 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: 8198775
    Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: June 12, 2012
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Patent number: 7956506
    Abstract: A rotating electric machine comprises a stator having stator salient poles, three-phases windings would around said stator salient poles, a rotor rotatable held inside the said stator, and permanent magnets inserted into said rotor and positioned opposite to said stator salient poles. The three-phase windings are concentratively wound around each of the stator salient poles, with windings of each phase wound around at more than one stator salient pole. The windings of each phase have a phase difference of voltage between at least one of the windings and the other.
    Type: Grant
    Filed: August 14, 2009
    Date of Patent: June 7, 2011
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobe, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Publication number: 20110062813
    Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.
    Type: Application
    Filed: November 22, 2010
    Publication date: March 17, 2011
    Applicants: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio TAJIMA, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Patent number: 7851959
    Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.
    Type: Grant
    Filed: March 12, 2009
    Date of Patent: December 14, 2010
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Patent number: 7847462
    Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.
    Type: Grant
    Filed: March 12, 2009
    Date of Patent: December 7, 2010
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Patent number: 7808144
    Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.
    Type: Grant
    Filed: March 12, 2009
    Date of Patent: October 5, 2010
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Patent number: 7671502
    Abstract: A rotating electric machine comprises a stator having stator salient poles, three-phases windings would around said stator salient poles, a rotor rotatable held inside the said stator, and permanent magnets inserted into said rotor and positioned opposite to said stator salient poles. The three-phase windings are concentratively wound around each of the stator salient poles, with windings of each phase wound around at more than one stator salient pole. The windings of each phase have a phase difference of voltage between at least one of the windings and the other.
    Type: Grant
    Filed: July 24, 2008
    Date of Patent: March 2, 2010
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobe, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keijiro Oda
  • Patent number: 7667365
    Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.
    Type: Grant
    Filed: July 18, 2008
    Date of Patent: February 23, 2010
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Publication number: 20090309449
    Abstract: A rotating electric machine comprises a stator having stator salient poles, three-phases windings would around said stator salient poles, a rotor rotatable held inside the said stator, and permanent magnets inserted into said rotor and positioned opposite to said stator salient poles. The three-phase windings are concentratively wound around each of the stator salient poles, with windings of each phase wound around at more than one stator salient pole. The windings of each phase have a phase difference of voltage between at least one of the windings and the other.
    Type: Application
    Filed: August 14, 2009
    Publication date: December 17, 2009
    Applicants: HITACHI, LTD., HITACHI CAR ENGINEERING CO., LTD.
    Inventors: Fumio Tajima, Yutaka Matsunobe, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keijiro Oda
  • Publication number: 20090174275
    Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.
    Type: Application
    Filed: March 12, 2009
    Publication date: July 9, 2009
    Applicants: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio TAJIMA, Yataka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Publication number: 20090174276
    Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.
    Type: Application
    Filed: March 12, 2009
    Publication date: July 9, 2009
    Applicants: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio TAJIMA, Yataka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Publication number: 20090174274
    Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.
    Type: Application
    Filed: March 12, 2009
    Publication date: July 9, 2009
    Applicants: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio TAJIMA, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Patent number: 7470108
    Abstract: In an axial flow fan, for reducing fluid noise and further reducing the noise by suppressing solid-conveyed noise (structure-borne noise) generated by the vibration of an electric motor or the like, the axial flow fan is equipped with a propeller, a motor for driving the propeller, and a venturi portion disposed on the outer circumference side of the propeller and provided on its inner circumferential side with a bellmouth through which an air flow generated by the revolution of the propeller passes, wherein the bellmouth has an intake portion whose diameter contracts in a curved shape in the direction of the air flow, a cylindrical portion having a cylindrical shape, and a discharge portion whose diameter slantingly expands in the direction of the air flow.
    Type: Grant
    Filed: April 20, 2005
    Date of Patent: December 30, 2008
    Assignee: Japan Servo Co., Ltd.
    Inventors: Masanori Watanabe, Taku Iwase, Shouichi Kawamata, Osamu Sekiguchi, Taro Tanno
  • Publication number: 20080284269
    Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.
    Type: Application
    Filed: July 18, 2008
    Publication date: November 20, 2008
    Applicants: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Publication number: 20080284270
    Abstract: A rotating electric machine comprises a stator having stator salient poles, three-phases windings would around said stator salient poles, a rotor rotatable held inside the said stator, and permanent magnets inserted into said rotor and positioned opposite to said stator salient poles. The three-phase windings are concentratively wound around each of the stator salient poles, with windings of each phase wound around at more than one stator salient pole. The windings of each phase have a phase difference of voltage between at least one of the windings and the other.
    Type: Application
    Filed: July 24, 2008
    Publication date: November 20, 2008
    Applicants: HITACHI, LTD., HITACHI CAR ENGINEERING CO., LTD.
    Inventors: Fumio TAJIMA, Yutaka Matsunobe, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Patent number: 7446448
    Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.
    Type: Grant
    Filed: August 25, 2006
    Date of Patent: November 4, 2008
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Patent number: 7417346
    Abstract: A permanent magnet rotating electric machine uses no skewing under a predetermined current and voltage condition to prevent torque from decreasing and to decrease pulsation torque to make the machine less vibrating and less noisy. The permanent magnet rotating electric machine includes a stator with multi-phase stator windings and a rotor with a plurality of permanent magnets internally embedded in a rotor core. The core shape of the rotor is uniform in the depth (longitudinal) direction with no skewing in the arrangement of the permanent magnets. The permanent magnets are symmetrical with respect to the rotation direction, but irregular with respect to the depth direction, for each pole. A magnetic flux generated from the between-pole permanent magnets almost equals a magnetic flux generated from the pole-center permanent magnet.
    Type: Grant
    Filed: May 14, 2007
    Date of Patent: August 26, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Yutaka Matsunobu, Fumio Tajima, Shouichi Kawamata, Takashi Yasuhara
  • Patent number: 7417349
    Abstract: A rotating electric machine comprises a stator having stator salient poles, three-phases windings wound around said stator salient poles, a rotor rotatable held inside the said stator, and permanent magnets inserted into said rotor and positioned opposite to said stator salient poles. The three-phase windings are concentratively wound around each of the stator salient poles, with windings of each phase wound around at more than one stator salient pole. The windings of each phase have a phase difference of voltage between at least one of the windings and the other.
    Type: Grant
    Filed: September 26, 2005
    Date of Patent: August 26, 2008
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobe, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keijiro Oda
  • Patent number: 7378773
    Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.
    Type: Grant
    Filed: August 25, 2006
    Date of Patent: May 27, 2008
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
  • Publication number: 20070210664
    Abstract: A permanent magnet rotating electric machine uses no skewing under a predetermined current and voltage condition to prevent torque from decreasing and to decrease pulsation torque to make the machine less vibrating and less noisy. The permanent magnet rotating electric machine includes a stator with multi-phase stator windings and a rotor with a plurality of permanent magnets internally embedded in a rotor core. The core shape of the rotor is uniform in the depth (longitudinal) direction with no skewing in the arrangement of the permanent magnets. The permanent magnets are symmetrical with respect to the rotation direction, but irregular with respect to the depth direction, for each pole. A magnetic flux generated from the between-pole permanent magnets almost equals a magnetic flux generated from the pole-center permanent magnet.
    Type: Application
    Filed: May 14, 2007
    Publication date: September 13, 2007
    Applicant: HITACHI, LTD.
    Inventors: Yutaka MATSUNOBU, Fumio TAJIMA, Shouichi KAWAMATA, Takashi YASUHARA