| 摘要 |
PURPOSE:To improve the water pressure characteristic by perfectly closing guide vanes through a shutter shaft. CONSTITUTION:When guide vanes 14 are closed, the contiguous edges 14a of the contiguous guide vanes 14 are closely attached onto the side surface of a shutter shaft 17, and the perfectly closed state of the guide vane can be obtained. When the close adhesion force of the guide vane 14 is reduced and the shutter shaft 17 is pulled outside a flow passage, a certain opening degree is provided for the guide vane 14. Then, the upstream-side pressurized water is introduced into a casing by opening a bypath valve, and the pressure is balanced by revolving a runner 16 at a low speed. Then, a portion of the upstream-side water pressure is discharged onto the runner 16 side, and the guide vane is prevented from being applied with all the water pressure. Therefore, thin guide vanes having the superior water-pressure characteristic can be used. |
