The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 16, 1996
Filed:
Sep. 13, 1994
Masao Siga, Hitachi, JP;
Yutaka Fukui, Hitachi, JP;
Mitsuo Kuriyama, Ibaraki-ken, JP;
Yoshimi Maeno, Hitachi, JP;
Masateru Suwa, Ibaraki-ken, JP;
Ryoichi Kaneko, Hitachi, JP;
Takeshi Onoda, Hitachi, JP;
Hidefumi Kajiwara, Katsuta, JP;
Yasuo Watanabe, Katsuta, JP;
Shintaro Takahashi, Hitachi, JP;
Toshimi Tan, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The present invention relates to a steam turbine comprising a rotor shaft integrating high and low pressure portions provided with blades at the final stage thereof having a length not less than 30 inches, wherein a steam temperature at first stage blades is 530.degree. C., a ratio (L/D) of a length (L) defined between bearings of the rotor shaft to a diameter (D) measured between the terminal ends of final stage blades is 1.4 to 2.3. This rotor shaft is composed of heat resisting steel containing by weight 0.15 to 0.4% C, not more than 0.1% Si, 0.05 to 0.25% Mn, 1.5 to 2.5% Ni, 0.8 to 2.5% Cr, 0.8 to 2.5% Mo and 0.15 to 0.35% V and, further, the heat resisting steel may contain at least one of Nb, Ta, W, Ti, Al, Zr, B, Ca, and rare earth elements.