Patents by Inventor Toshiaki Hotta

Toshiaki Hotta 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: 5502424
    Abstract: An alternating current generator for vehicle has a permanent magnet in the rotary field core unit. Providing such magnet is effective to reduce leakage magnetic flux and the size of the machine. In order to magnetize the magnet without trouble caused by machined chips or iron powder, the magnet is magnetized after the rotary field core has been machined. While the magnet is magnetized in a short period by a pulse current, the field coil is short-circuited. The field coil is subjected to magnetizing flux passing therethrough and generates short-circuit current and, consequently, counter magnetomotive force, which prevents leakage of the magnetizing flux.
    Type: Grant
    Filed: March 7, 1995
    Date of Patent: March 26, 1996
    Assignee: Nippondenso Co., Ltd.
    Inventors: Yoshihiro Kato, Toshiaki Hotta, Masaki Shimizu
  • Patent number: 5274322
    Abstract: In the alternating current generator for vehicle, an armature coil comprises a Y-connected first three-phase armature coil and a delta-connected second three-phase armature coil whose phase windings are inserted into same slots respectively. Each of the three-phase armature windings is provided with rectifying means for converting respective a.c. output into a direct current. The direct currents are summed to provide an output of the generator. It is effective to use a plurality of rotary magnet poles provided on a shaft of the generator for a compact a.c. generator in which the radial dimension of the rotary magnet poles is reduced.
    Type: Grant
    Filed: June 4, 1991
    Date of Patent: December 28, 1993
    Assignee: Nippondenso Co., Ltd.
    Inventors: Seiji Hayashi, Masato Hanai, Toshiaki Hotta, Keiichiro Banzai
  • Patent number: 5177388
    Abstract: A tandem type alternator comprises a rotor rotatably supported inside a housing and having rotor cores having magnetic poles formed on outer peripheral portions of the rotor cores, respectively, and a plurality of stators arranged on an inside wall of the housing and in tandem in the direction of the axis of rotation of the rotor and having tooth-shaped stator cores which are positioned to be opposite to the magnetic poles of the rotor cores and on which multi-phase windings are wound, respectively. The stators have respectively the multi-phase windings wound thereon so that both multi-phase windings are shifted from each other in the direction of the axis of rotation of the rotor. The housing has ventilation window portions formed between and near the plurality of stators which provide communication between the interior and exterior of the housing, so that ventilation resistance within the housing is reduced and the cooling effect is increased.
    Type: Grant
    Filed: May 21, 1991
    Date of Patent: January 5, 1993
    Assignee: Nippondenso Co., Ltd.
    Inventors: Toshiaki Hotta, Keiichiro Banzai
  • Patent number: 4617485
    Abstract: An improved construction of Randel-type rotor of a vehicle-mounted alternator, capable of reducing the windage noise which is produced as a result of interference between the rotor and the stator of the alternator. The rotor has a pair of pole cores provided with a plurality of mutually meshing claws, and an exciting coil disposed at the inner side of the pole cores. Spacers in the form of an integral ring or discrete wedges are fitted in the spaces between adjacent pole core claws so as to provide a substantially smooth cylindrical outer peripheral surface of the rotor portion facing the radial teeth on the stator.
    Type: Grant
    Filed: December 18, 1984
    Date of Patent: October 14, 1986
    Assignee: Nippondenso Co., Ltd.
    Inventors: Shigenobu Nakamura, Takayasu Nimura, Toshiaki Hotta
  • Patent number: RE36038
    Abstract: An improved construction of a .?.Randel.!. .Iadd.Lundell.Iaddend.-type rotor of a vehicle-mounted alternator, capable of reducing the windage noise which is produced as a result of interference between the rotor and the stator of the alternator. The rotor has a pair of pole cores provided with a plurality of mutually meshing claws, and an exciting coil disposed at the inner side of the pole cores. Spacers in the form of an integral ring or discrete wedges are fitted in the spaces between adjacent pole core claws so as to provide a substantially smooth cylindrical outer peripheral surface of the rotor portion facing the radial teeth on the stator.
    Type: Grant
    Filed: May 22, 1996
    Date of Patent: January 12, 1999
    Assignee: Denso Corporation
    Inventors: Shigenobu Nakamura, Takayasu Nimura, Toshiaki Hotta