VIBRATION REDUCING DEVICE FOR MOVING BLADE, AXIAL FLOW ROTARY MACHINE AND STEAM TURBINE

摘要

PROBLEM TO BE SOLVED: To provide a vibration reducing device for a moving blade that can suppress vibrations with simple structure. SOLUTION: Contact reaction force (frictional reaction force) of a shroud 5 of the moving blade 3 is optimally adjusted by driving a piezoelectric element 7, and the frictional reaction force is controlled to be maximum damping force depending on the number of rotations, and operation is performed in the contact reaction force at which the damping force of the moving blade 3 is continuously maximum. Therefore, the vibrations are suppressed with simple structure.