Patents Assigned to Tadashi Fukao
  • Patent number: 5955811
    Abstract: A high speed electromagnetic rotating machine is arranged to avoid heat generation due to mutual inductance between a stator and rotor and has a stator provided with drive windings for generating a rotating magnetic field to rotate the rotor and position control windings fitted to the stator for generating a magnetic field having a different number of poles than that of the drive windings for controlling the axial or radial position of the rotor when an electric current sufficient to unbalance the magnetic field applied to the rotor by the drive windings is supplied to the position control windings. The rotor has a cage conductors interconnected to form a plurality of closed circuits mounted to the rotor, the closed circuits having a number of poles set so that there is no mutual inductance between the position control windings and the cage conductors.
    Type: Grant
    Filed: February 8, 1996
    Date of Patent: September 21, 1999
    Assignees: Akira Chiba, Tadashi Fukao, Seiko Instruments Inc.
    Inventors: Akira Chiba, Tadashi Fukao, Yasushi Maejima
  • Patent number: 5880550
    Abstract: A variable-speed dynamotor has a stator having a first set of windings that provide a number of poles for rotating a rotor and a second set of windings that provide a number of poles different from the number of poles provided by the first set of windings. Voltages or currents supplied to the second set of windings are controlled to generate radial forces acting on the rotor for thereby controlling a radial position of the rotor, suppressing vibrations of the rotor, adjusting rotational balancing of the rotor, and controlling radial damping of the rotor.
    Type: Grant
    Filed: March 26, 1996
    Date of Patent: March 9, 1999
    Assignees: Tadashi Fukao, Akira Chiba, Chikara Michioka, Seiki Co., Ltd., Nikkiso, Co., Ltd., Ebara Corporation
    Inventors: Tadashi Fukao, Akira Chiba, Chikara Michioka
  • Patent number: 5880549
    Abstract: This invention relates to a switched reluctance rotator according to which a rotor can be rotated at a high speed without generating electromagnetic vibration at a rotating shaft and in which a current for generating of torque and a current for generating a radial force are passed through windings on the protruding poles of the stator or a winding for generating torque, and a winding for generating a radial force are wound on the protruding poles of the stator.
    Type: Grant
    Filed: January 16, 1997
    Date of Patent: March 9, 1999
    Assignees: Akira Chiba, Tadashi Fukao, Chikara Michioka, Nikkiso Company Limited, Ebara Corporation, Seiko Seiki Kabushiki Kaisha
    Inventors: Akira Chiba, Tadashi Fukao, Chikara Michioka
  • Patent number: 5703423
    Abstract: A flywheel for storing inertial energy is integral with a rotor which is rotatable around a stator. The stator has main windings that provide a number of poles for rotating the rotor and auxiliary control windings that provide a number of poles different from the number of poles provided by the main windings. When currents are supplied to the main windings, the rotor and hence the flywheel are rotated. When control currents are supplied to the auxiliary control windings, radial forces acting on the rotors are generated thereby to support the rotor out of contact with the stator.
    Type: Grant
    Filed: March 26, 1996
    Date of Patent: December 30, 1997
    Assignees: Tadashi Fukao, Akira Chiba, Chikara Michioka, Seiko Seiki Co., Inc., Nikkiso Co., Ltd., Ebara Corporation
    Inventors: Tadashi Fukao, Akira Chiba, Chikara Michioka