| 摘要 |
PROBLEM TO BE SOLVED: To prevent increase in the amount of working fluid leakage and excessive vibrations caused by the contact of the rotor of the axial-flow turbine and the seal fin. SOLUTION: A leaf spring 20 provided to the outer periphery of a seal ring 9 located at the upper half of a rotational rotor 5 holds down the seal ring 9 in the direction toward the center of the rotational rotor shaft. In order to correct the pressing force which becomes disproportionate by the own weight of each seal ring 9, strength of each leaf spring 20 is adjusted. A curved spring 17 inserted into a communicating groove 16 of the seal ring 9 is engaged with hook portions 18, 19 formed at the inset portion 8 of a nozzle diaphragm inner ring 3, pressing the seal ring 9 in the outer peripheral direction. In such a condition, if the pressure difference between the outside and inside peripheries is changed, the seal ring 9 moves in the radial direction of the rotational rotor shaft without any irregular movement. |
