| 摘要 |
PURPOSE:To raise the pump efficiency and to enable to draw out an impeller and other parts to the outside even if the diameter of the impeller is made greater than the inner diameter of guide vanes, by arranging blades of the impeller to suit the clearance formed between the impeller blades and the top end portion of each guide vane. CONSTITUTION:The diameter of blades 3a of an impeller 3 is D1, while a guide vane 6 is formed with triangular portion 8 extended inwards so that the minimum inner diameter D2 of the guide vanes 6 is smaller than D1. By employing such an arrangement, outlet portions 10 of the blades 3a are disposed as close to the inlet portions 11 of the guide vanes 6 as possible, so that the efficiency of converting the kinetic energy of water into pressure energy can be increased as compared with that of the conventional arrangements. In detaching the impeller by lifting it upward, the impeller is simply lifted upward after turning the same to a position where its blades 3a are located at the circumferential clearance of the guide vanes 6. |
