Patents by Inventor Kenzo Kajiwara

Kenzo Kajiwara 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: 5925947
    Abstract: An interior cooling air flow is moved by an interior fan through an inside ventilation passage provided on an inside surface of a stator frame of a totally-enclosed type motor. An exterior cooling air produced by an exterior fan is passed through an outside surface of ventilation passage provided on an outside the stator frame. An inner heat radiation rib is provided in the axial direction on an inner face the inside ventilation passage so that the temperature rise of the motor can be reduced by an improvement in the cooling characteristic. In this way, a compact size totally-enclosed type motor having an improved cooling characteristic is obtained.
    Type: Grant
    Filed: November 14, 1996
    Date of Patent: July 20, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Kenzo Kajiwara, Kouki Nagai, Kenji Takahashi, Heikichi Kuwahara
  • Patent number: 5481460
    Abstract: The present invention relates to a controller for an electric vehicle in which right and left drive wheels are respectively driven by drive motors which are individually provided. The controller for an electric vehicle comprises motors for driving right and left wheels, means for detecting rotating speeds or rotation torques of the wheels, and a facility for taking a rotation deviation between output signals from the detection means close to zero. As a result, the vehicle is always operated in safety.
    Type: Grant
    Filed: June 3, 1992
    Date of Patent: January 2, 1996
    Assignees: Hitachi, Ltd., Hitachi Automotive Engineering Co., Ltd.
    Inventors: Ryoso Masaki, Shigeki Morinaga, Kazuo Tahara, Hirohisa Yamamura, Kenzo Kajiwara, Hiroyuki Yamada, Nobuo Inoue, Toshio Suzuki
  • Patent number: 5304912
    Abstract: A control apparatus for an induction motor and an electric car propelling motor includes an inverter for supplying a driving current to the induction motor on the basis of a predetermined control signal, a rotational speed sensor for detecting a rotational speed of the induction motor, a V/f control circuit responsive to an input speed command signal for producing a control signal for the inverter, a vector control circuit for producing an inverter control signal on the basis of the speed command signal and the rotational speed signal of the rotational speed sensor, an abnormality detecting circuit for detecting abnormality of the rotational speed sensor.
    Type: Grant
    Filed: September 21, 1992
    Date of Patent: April 19, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Kenzo Kajiwara, Hiroshi Hamano, Hirohisa Yamamura, Ryoso Masaki
  • Patent number: 5139349
    Abstract: A bearing device for a horizontal shaft type rotating machine includes an oil tank formed at the lower portion of the bearing box for storing lubricant oil for the bearing, the oil tank being divided by a bearing support plate between an oil feeding chamber and an oil collecting chamber; an oil feeding apparatus which pumps up the lubricant oil in the oil feeding chamber and feeds the lubricant oil onto the bearing; and a pair of diffusion flow passages; each of the pair of diffusion flow passages being formed along the inner wall of the oil tank and connects the oil collecting chamber with the oil feeding chamber; each of the diffusion flow passages permitting diffusion and movement of the lubricant oil from the oil collecting chamber to the oil feeding chamber.
    Type: Grant
    Filed: October 4, 1991
    Date of Patent: August 18, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Masaaki Nakano, Kazuhiko Kawaike, Eiichi Okuyama, Kenzo Kajiwara