Steam turbine, rotor shaft thereof, and heat resisting steel
CA 2009120 C · Owner: Takahashi, Shintaro · Inventors: Watanabe, Yasuo; Fukui, Yutaka; Onoda, Takeshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
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°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 …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed February 1, 1990 and granted May 12, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 1, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 1, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
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Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.