| 摘要 |
PURPOSE:To enable to increase the efficiency of a water wheel, by making water flow downward along a helical groove formed in the peripheral wall of an impeller casing, and utilizing the resultant force of water flowing vertically downward and swirling flow of water. CONSTITUTION:Water in a volute casing 1 flows downward with swirl through a fluid passage 4 by means of guide vanes 12 and then through the inner space of an impeller casing 6 located under the volute casing 1. Here, since a helical groove 5 extending obliquely downward is formed in the peripheral wall of the impeller casing 6, water introduced into the impeller casing 6 with swirl imparted by the guide vanes 12 flows downward continuously with swirl and turns vanes or blades of a plurality of screw impellers 9 fixed to a turning shaft 10 in a circumferential direction of the turning shaft 10 by the resultant force of water flowing vertically downward and swirling flow of water, so that the shaft turning force can be increased. Thus, it is enabled to raise the efficiency of a water wheel. |
