| 摘要 |
PURPOSE:To reduce a leakage of steam by a labyrinth packing to be arranged in a clearance between a steam turbine rotor and a casing by a method wherein the packing is supported in the casing through a returning bimetal and a supporting spring. CONSTITUTION:A rotor 6 of a steam turbine has several grooves which are concentric with a rotary axis of the rotor, teeth are formed between the grooves and a ring-like labyrinth packing 8 is parts. The labyrinth packing 8 is provided with several fins 11 which are opposed to the rotor 6 with a clearance therebetween. In this case, the labyrinth packing 8 is arranged at a casing 7 in correspondence with the teeth formed assembled to the casing 7 through the returning bimetal 9 and a supporting spring 10 arranged such that they may be diplaced under their thermal expansion in an outward direction of the rotary shaft. Thereby, in case of operating a turbine, the labyrinth packing 8 can be moved toward a center of the rotary shaft of the rotor 6 in proportion to a displacement of thermal expansion so as to restrict a leakage of steam. |
