Patents by Inventor Yasuhiko Otawara

Yasuhiko Otawara 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: 5327718
    Abstract: A gas turbine apparatus has a gas turbine and a plurality of burners for providing combustion gas to drive the turbine. A flow control means of each burner for fuel or combustion air is adjusted by control means to control each said burner individually in dependence on a predetermined combustion characteristic of the respective burner. Sensed quantities relating to the combustion performance of the burners are input to the control means which adjusts the flow control means of each burner in dependence on the sensed quantities and the predetermined combustion characteristic of the respective burner.
    Type: Grant
    Filed: August 21, 1992
    Date of Patent: July 12, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Naohiko Iwata, Yasuhiko Otawara, Akira Shimura, Nobuyuki Iizuka, Isao Sato, Fumiyuki Hirose, Minoru Takaba, Yasutaka Komatsu, Hiraku Ikeda, Takeshi Iwamiya, Takeshi Ishida
  • Patent number: 5323614
    Abstract: A premixed combustor for a gas turbine, comprises, a combustion chamber for burning a fuel with an air therein, at least two premixed fuel/air mixture outlets which are juxtaposed with each other, and through each of which a premixed fuel/air mixture flows out into the combustion chamber, and a flow deflection member arranged between the premixed fuel/air mixture outlets, urging the permixed fuel/air mixture from one of the premixed fuel/air mixture outlets to go away from another one of the premixed fuel/air mixture outlets, and terminating in the combustion chamber so that the premixed fuel/air mixture from the one of the premixed fuel/air mixture outlets is permitted to move toward the premixed fuel/air mixture flowing out from the another one of the premixed fuel/air mixture outlets after going away from the another one of the premixed fuel/air mixture outlets.
    Type: Grant
    Filed: January 13, 1993
    Date of Patent: June 28, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Tsukahara, Hiroshi Inoue, Noriyuki Hayashi, Kazumi Iwai, Tamio Innami, Yoji Ishibashi, Michio Kuroda, Yasuhiko Otawara, Hiraku Ikeda, Kazuyuki Itoh, Shozo Nakamura, Hidekazu Fujimura, Kazuhito Koyama
  • Patent number: 4288677
    Abstract: A welding method of a turbine diaphragm for joining a spacer having a plurality of nozzle blades to outer and inner wheels. The spacer and the outer or inner wheel are welded from both sides. At first or inlet side of the diaphragm where a motive fluid flows into the diaphragm, the spacer and the outer and inner wheel are welded so that weld depth from the first side will be at most 0.5 L, wherein L is a distance between the first side and the top of the nozzle blade. At the second or outlet side of the diaphragm, from which the motive fluid exits, the spacer and the outer and inner wheels are weld so that a welded depth from the second side will be at least 0.3 C, wherein C is height of the nozzle blades.
    Type: Grant
    Filed: October 1, 1979
    Date of Patent: September 8, 1981
    Assignee: Hitachi, Ltd.
    Inventors: Shinji Sakata, Hirakazu Yokota, Tasuku Shimizu, Yasuhiko Otawara
  • Patent number: 4262538
    Abstract: Vibrations at a plurality of points on a turbine rotor and vibrations at corresponding points of the turbine stator are measured during a common sampling period for each corresponding points. Consequently, vibration data are obtained for each point on the turbine rotor and for each point on the turbine stator corresponding to the point on the turbine rotor. Then, a correlation coefficient representing the correlation between the vibration data of each point on the turbine rotor and the vibration data of corresponding point on the turbine stator is calculated, and the correlation coefficient is differentiated. The correlation coefficients and the differential values are then compared with respective predetermined reference values. The occurrence of rubbing is detected from the result of these comparisons.
    Type: Grant
    Filed: May 15, 1979
    Date of Patent: April 21, 1981
    Assignee: Hitachi, Ltd.
    Inventor: Yasuhiko Otawara
  • Patent number: 4228359
    Abstract: The present stress in the turbine rotor is estimated at each control period, from the steam temperature and pressure at the turbine inlet. In addition, the future turbine inlet steam temperature or pressure is preestimated once every n.sub.T control cycles, for a given speed or load changing rate, making use of data concerning the changing rate of the turbine steam inlet temperature or pressure in relation with the change of the speed or load, which has been obtained by a learning of the past turbine operating condition. This future steam temperature or pressure at the turbine inlet is used as a factor for preestimating the future stress expected to be caused in the turbine rotor. The preestimation of the rotor stress is performed for a plurality of assumed speed or load changing rates. The turbine is controlled at the maximum speed increase-rate or load changing rate which would not cause the future stress preestimated over a given preestimation time to exceed a limit stress.
    Type: Grant
    Filed: July 28, 1978
    Date of Patent: October 14, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Matsumoto, Yoshio Sato, Shigeyoshi Kawano, Yoshiyuki Nakano, Fumio Kato, Katsukuni Hisano, Katsuto Kashiwahara, Yasuhiko Otawara, Toshihiko Higashi, Yasuhiro Tennichi, Jube Matsumura, Koichiro Fukushima
  • Patent number: 4032255
    Abstract: A rotor fixing device for turbines comprising rotor support means independent of the bearing and including an inner ring member split into at least two sections and formed on its inner peripheral surface with grooves complementary with packing teeth formed on an outer peripheral surface of the turbine rotor, and an outer ring member split into at least two sections and secured to a turbine casin for supporting the inner ring member, and means secured to stationary members of the turbine and adapted to be inserted into a space defined between a rotor wheel and a packing case head for constraining axial movement of the turbine rotor. The rotor support means is disposed adjacent each end portions of the turbine rotor. The turbine rotor can be fixedly supported in place in an assembled condition during transportation of the turbine. The rotor fixing device is removed from the turbine after completion of transportation thereof.
    Type: Grant
    Filed: February 3, 1975
    Date of Patent: June 28, 1977
    Assignee: Hitachi, Ltd.
    Inventors: Nobuyuki Iizuka, Yasuhiko Otawara, Satoshi Ninomiya
  • Patent number: 3973404
    Abstract: Low pressure turbine installation comprising a casing, at least two groups of turbine stages mounted in said casing, each turbine stage having blades so arranged that a flow of steam passes through the respective turbine stages in contraflow manner, partition means in said casing for separating the opposed final stages of said turbine stages from each other, and steam exhausting means opened in the side walls of said casing in a direction substantially perpendicular to the axis of said turbine, said steam exhausting means being connected to condensers.
    Type: Grant
    Filed: January 21, 1975
    Date of Patent: August 10, 1976
    Assignee: Hitachi, Ltd.
    Inventors: Nobuyuki Iizuka, Katsukuni Hisano, Satoshi Ninomiya, Yasuhiko Otawara