Patents by Inventor Masayoshi Ohhira

Masayoshi Ohhira 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: 9028218
    Abstract: A steam turbine having a fork-type joint structure is provided that secures sufficient strength for endurance of stress corrosion cracking, low-cycle fatigue, and high-cycle fatigue, and extends an operating life while making it possible to endure long-term operation. The turbine includes a rotor having a plurality of rotor forks rowed in an axial direction; a turbine blade having blade forks arranged in the axial direction of the rotor, the blade forks engaged with the rotor forks; a plurality of pin holes whose positions are different from each other in the radial direction of the rotor; and a plurality of fork pins inserted into the plurality of pin holes in the axial direction of the rotor. A clearance exists between an inner diameter of the pin hole of the blade fork and a diameter of the fork pin, the clearance varying depending on positions in the axial direction of the turbine.
    Type: Grant
    Filed: May 30, 2012
    Date of Patent: May 12, 2015
    Assignee: Mitsubishi Hitachi Power Systems, Ltd.
    Inventors: Kunio Asai, Keiko Shishime, Yasuyoshi Harashima, Takeshi Kashiwagi, Hideyuki Nomura, Takafumi Wakasa, Masayoshi Ohhira
  • Publication number: 20120308390
    Abstract: A steam turbine having a fork-type joint structure is provided that secures sufficient strength for endurance of stress corrosion cracking, low-cycle fatigue, and high-cycle fatigue, and extends an operating life while making it possible to endure long-term operation. The turbine includes a rotor having a plurality of rotor forks rowed in an axial direction; a turbine blade having blade forks arranged in the axial direction of the rotor, the blade forks engaged with the rotor forks; a plurality of pin holes whose positions are different from each other in the radial direction of the rotor; and a plurality of fork pins inserted into the plurality of pin holes in the axial direction of the rotor. A clearance exists between an inner diameter of the pin hole of the blade fork and a diameter of the fork pin, the clearance varying depending on positions in the axial direction of the turbine.
    Type: Application
    Filed: May 30, 2012
    Publication date: December 6, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Kunio Asai, Keiko Shishime, Yasuyoshi Harashima, Takeshi Kashiwagi, Hideyuki Nomura, Takafumi Wakasa, Masayoshi Ohhira