Patents by Inventor Tsuguaki Koga

Tsuguaki Koga 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: 5121597
    Abstract: A gas turbine combustor and a method of operating the gas turbine combustor, with the gas turbine combustor comprising a combustion sleeve, a combustion sub-chamber disposed at an upstream side of the combustion sleeve and having an air and fuel supply system, and a combustion main chamber disposed on a downstream side of the sub-chamber and having an air and fuel supply system. The combustion sub-chamber and combustion main chamber are formed in such a manner that the start-up of the gas turbine is effected by the hot combustion gas generated in the sub-chamber. The combustion sub-chamber is provided with an inner sleeve protruding from a side wall of the sub-chamber such that a tip of the inner sleeve is located in the vicinity of a downstream end of the sub-chamber, and a fuel nozzle is provided in a tip of the inner sleeve for increasing the fuel-to-air ratio during an initiating period of an increase in the gas turbine rotation speed.
    Type: Grant
    Filed: January 26, 1990
    Date of Patent: June 16, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Haruo Urushidani, Seiichi Kirikami, Isao Sato, Nobuo Shimizu, Osamu Arai, Akira Shimura, Michio Kuroda, Tsuguaki Koga, Tadashi Kurokawa, Yoji Ishibashi, Katsukuni Hisano
  • Patent number: 4523286
    Abstract: A diagnostic apparatus for diagnosising of a valve device in a turbine system comprises at least one of a pressure sensor for sensing hydraulic pressure in a hydraulic cylinder for driving a valve body of the valve device and a position sensor for sensing the displacement of the valve body, and a processing device for processing the output signal from the above-mentioned at least one sensor. The processing device has an offset computing device which receives a signal representing the actual operating state of the valve device obtained on the basis of the output signal from the at least one sensor and a signal corresponding to a reference value obtained under the normal operating state of the valve device. The offset computing device is operable to compute the offset between the signals received thereto. A judging device is provided for judging as to whether or not there is a symptom of a sticking in the valve device, in accordance with the output signal from the offset computing device.
    Type: Grant
    Filed: August 5, 1982
    Date of Patent: June 11, 1985
    Assignees: Hitachi, Ltd., Hitachi Engineering Co., Hitachi Service Engineering Co., Ltd.
    Inventors: Tsuguaki Koga, Hidesumi Kuwashima, Hidenori Inoue, Hidetoshi Hamaoka, Hiroshi Ohta
  • Patent number: 4481819
    Abstract: A method and apparatus for detecting metal wipe damages of plane bearings with the metal wipe generating an ultrasonic signal as an acoustic emission signal when it occurs. The ultrasonic signal has a periodic appearance therefore, the metal wipe damages, can be detected by monitoring the periodic nature of the ultrasonic signal. The ultrasonic signal is received by a transducer fixed to the plane bearing with the periodic nature of the received ultrasonic signal being computed by a processing unit so as to provide a output signal of the occurrence of a metal wipe when the received ultrasonic signal is periodic.
    Type: Grant
    Filed: February 9, 1983
    Date of Patent: November 13, 1984
    Assignee: Hitachi, Ltd.
    Inventors: Takao Yoneyama, Ichiya Satoh, Sanshiro Obara, Tomoaki Inoue, Tsuguaki Koga
  • Patent number: 4478082
    Abstract: A method and apparatus for detecting the occurrence of rubbing in a rotary machine, in which at least one acoustic sensor is mounted on at least the rotor part or the stator part of the rotary machine, and the output signal from the acoustic sensor is detected and then filtered to extract a frequency component having a frequency substantially equal to the rotational frequency of the rotary machine, so as to detect the occurrence of rubbing in the rotary machine as early as possible and also to locate the source of the rubbing. Even when the occurrence of abnormal metal-to-metal contact at a bearing of the rotary machine is detected, it is discriminated from rubbing so that the occurrence of the rubbing can be reliably detected.
    Type: Grant
    Filed: August 17, 1982
    Date of Patent: October 23, 1984
    Assignee: Hitachi, Ltd.
    Inventors: Ichiya Sato, Takao Yoneyama, Tsuguaki Koga, Kazuo Ikeuchi, Katsukuni Hisano
  • Patent number: 4406169
    Abstract: A method of and a system for monitoring the conditions of a journal bearing having a bearing surface for supporting a rotatable shaft through an oil film. Detectors detect the speed of rotation of the shaft and the pressure of the oil film. The load on the journal bearing is calculated based on the rotational speed of the shaft and the pressure of the oil film.
    Type: Grant
    Filed: April 29, 1981
    Date of Patent: September 27, 1983
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Ikeuchi, Tsuguaki Koga, Tomoaki Inoue, Katsumi Oyabu
  • Patent number: 4376389
    Abstract: A method of and an apparatus for diagnosis of the operating conditions of a bearing wherein pressures of a film of oil formed on a sliding surface of the bearing journalling a rotary shaft are detected at a plurality of points on the sliding surface, and the pressure differential between the pressures of the oil film detected at the plurality of points is calculated. The deflection of the bearing with respect to the rotary shaft is calculated based on the calculated oil pressure film pressure differential, so that the operating conditions of the bearing are judged based on the deflection thereof.
    Type: Grant
    Filed: November 25, 1980
    Date of Patent: March 15, 1983
    Assignee: Hitachi, Ltd.
    Inventors: Tomoaki Inoue, Kinpei Okano, Kazuo Ikeuchi, Tsuguaki Koga
  • Patent number: 4098127
    Abstract: A balancing method for use in a multiple-span rotor shaft system for a prime mover, such as a large-capacity, large-sized steam turbine and generator. A balancing influence coefficient representing the relationship between a unit weight and the resultant vibration, when the aforesaid unit weight is attached to a given balance-correcting plane of a multiple span rotor, is first determined, and then a balance-correcting plane, to which is to be attached a balancing weight, is selected, then a balancing weight is determined so as to minimize the value of the residual vibration amplitude, by using the method of least squares, which values are dependent on the value of the vibration amplitude, influence coefficients and balancing weights. Thus, a weight corresponding to the aforesaid balancing weight is attached to the aforesaid balance-correcting plane to reduce vibrations in a shaft.
    Type: Grant
    Filed: September 30, 1976
    Date of Patent: July 4, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Motohiro Shiga, Fumio Fujisawa, Kazuo Sato, Kouki Shiohata, Masakazu Takasumi, Tsuguaki Koga