| 摘要 |
PURPOSE:To enhance the performance by making the angle formed by the outer periphery of blade and the axis larger than 45 deg. and making the angle formed by the outer periphery of disklike blade and the axis smaller than 45 deg.. CONSTITUTION:A runner 10 has a disk part 12 provided perpendicularly to the axis, on which nearly triangular blade 13 is fitted to be projected. The angle A formed by the outer periphery of blade 13 and the axis is made greater than 45 deg., and a disklike blade 14 is provided below the blade 13 including the axis, and the angle B formed by the outer periphery of the disklike blade 14 and the axis made smaller than 45 deg.. Thus, the effective area of blade increases steeply according to the slight rise of level to enable a large quantity of water to drain, and the drainage capacity according the supply water quantity can be developed. |
