Patents by Inventor Tatsuro Ishizuka

Tatsuro Ishizuka 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).

  • Steel rotor shafts of electric machines
    Patent number: 5548174
    Abstract: New low-alloy steel compositions and rotor shafts for electric machines made from them are described. High nickel and chromium contents ensure high strength and toughness, while other components, notably silicon and other impurities, are kept low with the result that magnetic properties remain good. One aspect provides a steel with the following proportions by weight:______________________________________ C 0.15 to 0.3% Si <0.1% Mn <1% Ni 3 to 5% Cr >2%, <3.5% (Mo + W) 0.1 to 1.0%, W being optional V 0.03 to 0.35%, ______________________________________and the remainder substantially Fe.Other aspects are also described.
    Type: Grant
    Filed: February 15, 1995
    Date of Patent: August 20, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Masao Siga, Mitso Kuriyama, Takanobu Mori, Yutaka Fukui, Tatsuro Ishizuka
  • Steel rotor shafts for electric machines
    Patent number: 5437742
    Abstract: New low-alloy steel compositions and rotor shafts for electric machines made from them are described. High nickel and chromium contents ensure high strength and toughness, while other components, notably silicon and other impurities, are kept low with the result that magnetic properties remain good. One aspect provides a steel with the following proportions by weight:C 0.15 to 0.3%Si <0.1%Mn <1%Ni 3 to 5%Cr >2%, <3.5%(Mo+W) 0.1 to 1.0%, W being optionalV 0.03 to 0.35%,and the remainder substantially Fe.Other aspects are also described.
    Type: Grant
    Filed: December 2, 1993
    Date of Patent: August 1, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Masao Siga, Mitso Kuriyama, Takanobu Mori, Yutaka Fukui, Tatsuro Ishizuka
  • Steel for rotor shafts of electric machines and method and product thereof
    Patent number: 5288455
    Abstract: New low-alloy steel compositions and rotor shafts for electric machines made from them are described. High nickel and chromium contents ensure high strength and toughness, while other components, notably silicon and other impurities, are kept low with the result that magnetic properties remain good. One aspect provides a steel with the following proportions by weight:C 0.15 to 0.3%Si <0.1%Mn <1%Ni 3 to 5%Cr >2%, <3.5%(Mo+W) 0.1 to 1.0%, W being optionalV 0.03 to 0.35%,and the remainder substantially Fe.Other aspects are also described.
    Type: Grant
    Filed: March 17, 1992
    Date of Patent: February 22, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Masao Siga, Mitso Kuriyama, Takanobu Mori, Yutaka Fukui, Tatsuro Ishizuka
  • Feeder lead wire of rotor for electric machine
    Patent number: 5063320
    Abstract: A rotor for an electric rotating machine includes a rotor winding, and a feeder lead wire connected to an inner end of the rotor winding so as to supply field current to the rotor winding. The feeder lead wire has a rising portion extending radially outwardly of a rotatable shaft, and a connecting terminal extending from the rising portion in a circumferential direction of the rotatable shaft.
    Type: Grant
    Filed: September 14, 1990
    Date of Patent: November 5, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Watanabe, Tatsuro Ishizuka