| 摘要 |
PURPOSE:To obtain the stable pumping-up characteristic for a long period by embedding the solidable bodies made of a material having the superior abrasion resistance, electric errosion resistance, errorsion resistance onto the liner surface sides of a runner and the upper and the lower casing and permitting the surface contact of the slidable bodies each other. CONSTITUTION:Slidable bodies 20', 21', 20, and 21 which are made of ceramics having the superior abrasion resistance, electric-errosion resistance, and errosion resistance are interposed between the respective liner surfaces 6A, 6B, 15, and 16 of the upper and the lower casings 4 and 3 and a runner 6, and the slidable bodies are attached closely each other. With such constitution, the initial pumping-up characteristic is improved by a large margin in comparison with that in the conventional technique, and the errosion resistance for well water is improved, and the abrasion and lock phenomenon due to the sand contained in the well water are prevented, and thus the stable water pumping-up characteristic can be obtained for a long period. |
