Patent ID: 6155783
Filing Date: 2000-12-05
Classification: F03B,Y02E,Y02P,Y10T

Abstract:
A method of making a hollow blade for a hydraulic turbine or pump, the blade including an inner edge and an opposed outer edge, a leading edge and an opposed trailing edge, and a curved suction surface and an opposed curved pressure surface, the method comprising the steps of:shaping a first generally flat plate into a curved pressure-side member including at least a substantial portion of the curved pressure surface and an opposed first inner surface, the pressure-side member having a curved hydrofoil shape including a generally flat upper portion and a three-dimensionally curved lower portion;shaping a second generally flat plate into a curved suction-side member including at least a substantial portion of the curved suction surface and an opposed second inner surface, the suction-side member having a complementary curved hydrofoil shape including a generally flat upper portion arid a three-dimensionally curved lower portion; andfixedly securing the curved pressure-side and suction-side members together with the first and second inner surfaces facing each other, wherein at least a portion of the first inner surface is spaced from at least a portion of the second inner surface to form a cavity within the blade, the cavity having a complex geometry and extending from between the generally flat upper portions to between the curved lower portions.