| 摘要 |
PURPOSE:To reduce the weight of the device under securing a desired strength by a method wherein the fore and aft rims of the vane for the runner as well as the root of the inner peripheral side therefor are formed integrally as a steel casting product while the other parts thereof are formed by arranging steel plate members on both surfaces of a lattice-shaped ribs. CONSTITUTION:The vane of the runner is consisting of the main frame 1, a shaft 2 and a flange 3, fitted to the peripheral surface of the boss of the runner. In this case, the fore rim 11, the aft rim 12 and the root 13 of the inner peripheral side, excluding the central and outer peripheral rim zones in the main frame 1, are produced integrally with the shaft 2 and the flange 3 as the steel casting product. The steel plate members 15, 16 are arranged on both surfaces of the lattice-shaped ribs 14, around which the steel casting product is not existing, and both of the ribs 14 and the plate members 15, 16 are welded mutually. According to this method, the weight may be reduced as compared with the conventional vane, in which the whole of the vane is produced as the solid steel casting product, and the manufacturing cost thereof may also be reduced. On the other hand, the sufficient strength of the vane may be secured by the structure of frame and rib made of the integral steel cast product. |
