| 摘要 |
PROBLEM TO BE SOLVED: To improve reliability of a steam governing valve for a steam turbine in operation at a large valve-opening state. SOLUTION: The steam governing valve has a valve element, a valve stem, a piston rod and a piston for driving the valve stem, a hydraulic cylinder receiving the piston and hydraulically driving the piston in a valve opening direction, a main spring circumferentially surrounding the piston rod and urging the piston rod in the valve opening direction, a main spring box surrounding an outer periphery of the main spring with an end of the main spring fixed to it and having a slit axially extending, a spring support fixed to the other end of the main spring and axially reciprocating with respect to the main spring box, a guide roller 20 attached to an outer peripheral part of the spring support and rotatable in the slit, and a frame member 23 detachably attached inside the slit and arranged to surround the slit at a side surface of the slit and an end of the slit to which the guide roller 20 contacts in the maximum valve opening state. COPYRIGHT: (C)2009,JPO&INPIT
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