| 摘要 |
PROBLEM TO BE SOLVED: To reduce man-hours, costs, and pars costs in a die manufacturing by solving such problems in a hermetically closed type impeller of a self-priming pump, for joining a front face shroud and a blade by welding wherein a groove is formed to the blade or two or more projections are formed to the blade for positioning between the front face shroud and the blade and the front face shroud side is formed with a hole or the like fitted to the projections of the blade, thereby requiring dimensional accuracy. SOLUTION: A step 19 is formed to an edge face of the blade 5, the edge face being joined to the front face shroud 6 side, whereby an inlet side of the edge face is made high and a water supply side is made low. The low side edge face of the blade 5 is provided with a positioning pin 8 whose height is lower than the height of the step 19. The front face shroud 6 is provided, at its center, with an entrance, and further provided with a fit hole fitted to the positioning pin 8. The front face shroud 6 is attached to the blade 5 with the step 19 serving as a positioning guide. Accordingly, the hermetically closed type impeller of the self-priming pump is formed.
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