Patents by Inventor Yosio Furukawa

Yosio Furukawa 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: 4870339
    Abstract: A variable-speed power generating system comprises a variable-speed generator electrically connected at its primary winding to an electric power system and its secondary winding to the electric power system through a frequency converter and mechanically coupled to a driver driving the secondary side thereof, a phase detector generating an output signal representing a slip frequency in response to the application of a first input having a frequency component of an output generated from the primary winding of the variable-speed generator and a second input having a frequency component corresponding to the rotation speed of the driver, a controller controlling the frequency converter on the basis of a reference phase provided by the output signal of the phase detector, and regulating means for controlling the frequency converter so that, when the variable-speed generator is disconnected from the electric power system, the frequency applied to the secondary winding of the variable-speed generator may not deviate
    Type: Grant
    Filed: January 15, 1988
    Date of Patent: September 26, 1989
    Assignees: Hitachi Ltd., The Kansai Electric Power Co., Inc.
    Inventors: Yosio Furukawa, Yasuhiro Yasaka, Osamu Nagura, Eiji Haraguchi, Hiroto Nakagawa, Yasuteru Oono
  • Patent number: 4812730
    Abstract: A generator/motor system comprises a generator/motor having a primary winding and a secondary winding installed on the motor rotor coupled to a prime mover/load, a main circuit interposed between a power system and the primary winding of the generator/motor, an excitation circuit including a frequency converter inserted between a part of the main circuit and the secondary winding of the generator/motor, a frequency difference detector for determining the difference between the frequency of the power system and a frequency dependent on the rotational speed of the load, and a phase-shift control device for controlling the firing phase of the frequency converter in the excitation circuit by use of a signal from the frequency difference detector as a reference signal.
    Type: Grant
    Filed: April 6, 1987
    Date of Patent: March 14, 1989
    Assignees: Hitachi, Ltd., Kansai Electric Power Co., Inc.
    Inventors: Hiroto Nakagawa, Yasuteru Oono, Tadaatsu Kato, Osamu Nagura, Sadahiko Niwa, Yosio Furukawa, Shigehiro Kayukawa
  • Patent number: 4291926
    Abstract: A guide bearing device for vertical rotary shafts including a plurality of segmental pads disposed circumferentially equidistantly around the rotary shaft, a plurality of adjusting bolts each supporting the respective segmental pads for pivotal movement, a housing containing the segmental pads and adjustably mounting the adjusting bolts and filled with lubricating oil, and a plurality of cooling pads each formed with an oil passage and arranged between the two adjacent segmental pads for pivotal movement, each of the cooling pads defining between its inner surface and the outer circumferential surface of the rotary shaft a gap which is thicker than the gap defined between a sliding surface of the respective segmental pads and the outer circumferential surface of the rotary shaft, said oil passage of each cooling pad communicating with a pressurized oil supply source and discharging lubricating oil toward the outer circumferential surface of the rotary shaft.
    Type: Grant
    Filed: September 21, 1979
    Date of Patent: September 29, 1981
    Assignee: Hitachi, Ltd.
    Inventors: Shunzo Tomioka, Kinpei Okano, Masanori Matsuo, Yosio Furukawa
  • Patent number: 4246505
    Abstract: A rotor for electric rotating machines has a plurality of salient poles arranged at certain intervals with each other along the outer periphery of the rotor rim. Each of the shield plates of the rotor has a plurality of reinforcing ribs arranged between adjacent salient poles and extending along the periphery of the rotor. The eddy currents flowing in the shield plates are reduced, thus reducing the eddy current losses.
    Type: Grant
    Filed: March 19, 1979
    Date of Patent: January 20, 1981
    Assignee: Hitachi, Ltd.
    Inventors: Yasuhiro Yasaka, Yosio Furukawa