STRUCTURE OF CASCADE OF ROTARY BLADES IN AXIAL FLOW ROTARY MACHINE

摘要

PURPOSE:To enhance the workability of weldment and to make it possible to remove residual stress by weldment, by welding a plurality of rotary blades to a connecting block to form a rotary blade cascade before the blades are planted on a rotor disc. CONSTITUTION:A shroud 2 and a root welding section 3 are shaped integrally with rotary blades 1. Further, the shroud 2 is formed therein a bevel 12 adapted to be welded to the shroud of the adjacent rotary blade. Further, the widthwise center of outer peripheral surface 13 of a connecting block 4 for connecting rotary blades 1 is made to be large while the both sides thereof are made to be small so that a welding bevel is formed. Further, after, for example, five rotary blades 1 are bundled, they are welded to the outer peripheral surface of the connecting block 4. Then, the cascade of blades are heat-treated to remove residual stress therefrom. Thereafter, the coupling block 4 is formed therein with welding grooves 7 and pin holes 8, and then is planted on a rotor disc 9.