| 摘要 |
A stage of an axial flow steam turbine includes a rotor having a plurality of spaced apart buckets (32) and a plurality of spaced apart nozzle partitions (30) which are circumferentially spaced such that the minimum throat (S*) between adjacent partition pairs extends a predetermined radial distance along (111), along a locus (110) from the root, thereby forming a converging-diverging flow passageway between nozzle partitions. The trailing edges (31) of the nozzle partitions are disposed to include axial and tangential lean with respect to the rotor. The buckets (32) include a plurality of tip covers respectively connecting the tips and having a single outward radially extending sealing rib (36) on the radially outer surface of each cover, each rib (36) being tangentially aligned with respective adjacent ribs. The buckets (32) are overtwisted to compensate for untwist at operational speed to achieve optimum efficiency and they are interconnected, intermediate their lengths by lashing (41) for providing mechanical coupling at operational speed. <IMAGE> |
