| 摘要 |
<p>PURPOSE:To reduce trouble of an impeller, by permitting a blade to freely move within a prescribed swing angle, and restricting the swing of the blade exceeding said angle with the aid of a spring thereby unduly load would not be imposed on the blade. CONSTITUTION:The stoppers 4a, 4a, 4b, 4b for restricting the swing angle of the blades 3a, 3b are formed by extending the ends of coil springs 6a, 6b fixed at their centers to a rotating shaft 1 by pins 5, and thus the swing of the blades can be slightly increased against the force of the springs beyond the prescribed swing angle alpha to alpha'. Consequently, if the flow rate of water is temporarily increased as in the case of flood, unduly load would not be imposed on the blades 3a, 3b, and therefore trouble would hardly occur.</p> |
