| 摘要 |
PURPOSE:To reduce the water thrust caused by runner back pressure and the design load of a thrust bearing, by guiding the pressurized water staying in an iron pipe to a runner lateral pressure chamber when a transient phenomenon such as the interception of the load of a pump water wheel or the like occurs. CONSTITUTION:A back pressure chamber 1 is connected to a lateral pressure chamber 3 through a balance tube 4, and on the way of this connecting route, an automatic valve 15 is interposed, while an automatic valve 14 is also interposed on a water supply tube 13 by which the balance tube 4 and a container 7 are connected to each other. A back pressure chamber 2 is connected to a draft pipe 9 by a balance tube 5. Under normal conditions, the automatic valve 14 is closed and the automatic valve 15 is opened by a control device not figured. But, in the case that a water thrust is generated when a transient condittion such as the interception of load or the like occurs, the automatic valve 14 is opened and the automatic valve 15 is closed, and then the water pressure in the iron pipe is guided to the lateral pressure chamber 3. Thereby, the water thrust during the transition period is reduced to the normal water thrust or below. |
