| 摘要 |
PURPOSE:To reduce stress generated at each part of moving blades which are arranged on the circumference of a turbine rotor and improve steam sealing performance by fixing a shroud at each external end of the moving blades and tightening the moving blades in the internal radial direction thereof so as to apply compressive stress to the moving blades in advance. CONSTITUTION:In a steam turbine, a plurality of moving blades 2 are arranged on the circumference of the rotor 1 of the turbine. In this case, a ring-like shroud is forced onto the external end parts of the moving blades 2 so that all of the moving blades 1 around the rotor 1 are fixed as a unit. A radially projecting part 8 is formed on the external end of each of the moving blades 2 while a recess part 9 which receives the projecting part 8 is formed on the internal peripheral face of the shroud 5. A plurality of ring-like projections 10 are formed on the external peripheral face of the shroud 5 and a plurality of fins 6 are projected axially at intervals on the internal face of a packing ring 7 which is provided on the side of an external turbine casing.
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