| 摘要 |
PURPOSE:To reduce vibration and noise by forming an air chamber which communicates to the runner back-pressure chamber and/or the runner side-pressure chamber of a hydraulic machine and connecting an air feeding pipe equipped with an air feeding valve to the air chamber, thus suppressing the water-pressure pulsation in the back-pressure chamber and the side-pressure chamber. CONSTITUTION:A Francis-type hydraulic machine is equipped with a runner 2 surrounded with the upper and the lower covers 6 and 7, and guide vanes 10... are annularly arranged onto the outer periphery of the runner 2. The upper cover 6 is opposed to a runner crown 3, and a runner back-pressure chamber 8 is formed therebetween, and the lower cover 7 is opposed to a runner band 4, and a runner side pressure chamber 9 is formed therebetween. In this case, an annular air chamber 12 is formed outside the upper cover 6 and communicates to the runner back-pressure chamber 8 through a communication passage 13. An air feeding pipe 14 equipped with an air feeding valve 15 is connected to the air chamber 12, and air is supplied according to circumstances into the air chamber 12 on the basis of the output of a water-level sensor 16. Therefore, the water level in the air chamber 12 is kept at a prescribed level. |
