Patents by Inventor Akihito Nakahara

Akihito Nakahara 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: 7535147
    Abstract: The object of the invention is to provide a generator easy to assemble even if there is an obstacle such as a turbine in the axial direction of the rotor of the generator. A generator comprising: a rotor having a permanent magnet placed therein and supported to be rotatable, and a stator having a field coil wound thereon, characterized in that, the rotor is provided with a seating made of a magnetic material for supporting the permanent magnet and a pole shoe made of a magnetic material placed in the outward radial direction of the permanent magnet.
    Type: Grant
    Filed: February 17, 2006
    Date of Patent: May 19, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Akihito Nakahara, Kazumasa Ide, Mamoru Kimura, Kazuhiko Takahashi
  • Publication number: 20080088196
    Abstract: An electric rotating machine comprising a stator core having a plurality of slots that are equally spaced on the inner surface of the stator core in the peripheral direction, a rotor that rotates inside the stator core, and an armature winding that is applied to each of the slots, wherein the armature winding is made up with a plurality of serially-connected single-turn coils that are respectively applied to the slots and the serially-connected coils of respective phases are connected in parallel.
    Type: Application
    Filed: August 23, 2007
    Publication date: April 17, 2008
    Inventors: Kazuhiko Takahashi, Mitsuru Saeki, Kenichi Hattori, Masami Sukeda, Akihito Nakahara
  • Publication number: 20070145848
    Abstract: A rotation machine is configured such that permanent magnets and pole shoes holding the permanent magnets at the outer diameter side of the permanent magnets are provided for a rotor, and an outer diameter size (Ra) in the axial end portion of the pole shoe is made smaller than an outer diameter size (Rb) in the axial center portion.
    Type: Application
    Filed: December 26, 2006
    Publication date: June 28, 2007
    Inventors: Akihito Nakahara, Kazuhiko Takahashi, Mamoru Kimura, Akitomi Semba
  • Publication number: 20060214528
    Abstract: The object of the invention is to provide a generator easy to assemble even if there is an obstacle such as a turbine in the axial direction of the rotor of the generator. A generator comprising; a rotor having a permanent magnet placed therein and supported to be rotatable, and a stator having a field coil wound thereon, characterized in that; the rotor is provided with a seating made of a magnetic material for supporting the permanent magnet and a pole shoe made of a magnetic material placed in the outward radial direction of the permanent magnet.
    Type: Application
    Filed: February 17, 2006
    Publication date: September 28, 2006
    Inventors: Akihito Nakahara, Kazumasa Ide, Mamoru Kimura, Kazuhiko Takahashi
  • Publication number: 20060138881
    Abstract: A rotating shaft is required to have an overhang for the mounting of a generator for an AC-exciter, the shaft length being increased correspondingly. The overhang may become the cause of generating shaft vibrations. A turbogenerator has a rotor over which a field winding is disposed, a coupling co-cut from a rotor shaft, an AC exciter for supplying a DC current to the field winding through a rectifier, and a generator for the AC-exciter, the generator including a permanent magnet as a field generator and supplying a DC current to a field winding of the AC exciter through the rectifier. The AC exciter and the generator are disposed over the rotor shaft. The rotor is rotated through engagement between a turbine and the coupling. The generator for the AC-exciter is mounted in a position on the side nearer to the turbine than a stator of the turbogenerator.
    Type: Application
    Filed: August 19, 2005
    Publication date: June 29, 2006
    Inventors: Akihito Nakahara, Kazuhiko Takahashi, Kazumasa Ide, Mamoru Kimura
  • Publication number: 20060043820
    Abstract: An electrical rotating machine including a stator core is provided. The stator core is formed of substantially sector-shaped sheet segments die-cut from electrical steel sheets and arranged in a circumferential direction of the stator core to form circular sheets which are stacked in an axial direction of the stator core. In the electrical rotating machine, end regions of the stator core are formed of stacked sheet segments die-cut from non-grain oriented steel sheets, and the other region of the stator core is formed of stacked sheet segments die-cut from grain oriented steel sheets.
    Type: Application
    Filed: July 29, 2005
    Publication date: March 2, 2006
    Inventors: Akihito Nakahara, Kazuhiko Takahashi, Kazumasa Ide, Junya Kaneda, Kenichi Hattori, Takashi Watanabe