Steam turbine valve drive apparatus

A steam turbine valve drive apparatus comprising:

• a piston provided at an operation rod that operates a steam valve installed in a flow passage for steam flowing to a steam turbine;
• a cylinder housing the piston in an inner space thereof, the inner space being partitioned by the piston into a first hydraulic chamber and a second hydraulic chamber;
• a bidirectional pump configured to execute an opening operation of the steam valve by feeding a working oil to the first hydraulic chamber and configured to execute a closing operation of the steam valve by feeding the working oil to the second hydraulic chamber;
• a servo motor configured to drive the bidirectional pump;
• and
• a quick closing mechanism configured to execute a quick closing operation of closing the steam valve more quickly than the closing operation,
• wherein the quick closing mechanism includes:
• a first dump valve arranged in a first quick closing oil passage configured to connect to the first hydraulic chamber,
• a second dump valve arranged in a second quick closing oil passage configured to connect to the second hydraulic chamber,
• a quick closing electromagnetic valve configured to open the first dump valve and the second dump valve during execution of the quick closing operation,
• a first blocking electromagnetic valve arranged in a first opening degree controlling oil passage connecting between the bidirectional pump and the first hydraulic chamber, which is configured to block the first opening degree controlling oil passage during the execution of the quick closing operation, and
• a second blocking electromagnetic valve arranged in a second opening degree controlling oil passage connecting between the bidirectional pump and the second hydraulic chamber, Which is configured to block the second opening degree controlling oil passage during the execution of the quick closing operation, wherein
• by executing the quick closing operation, the quick closing mechanism is configured to feed the working oil accumulated in an accumulator to the second hydraulic chamber and configured to drain the working oil from the first hydraulic chamber to a reservoir.