To suppress the occurrence of a problem with a conventional drain pump, particularly, to suppress occurrence of vibration and noise when the drain pump is operated at a low lift.
This drain pump 1 comprises a funnel-shaped housing 2 rotatably storing a runner 10 having a plurality of swing vanes 14. An inflow port 5 is provided at the lower end part of the housing, and a delivery port 8 is provided at the upper large diameter part thereof. On the large diameter side, a small diameter vane 13 arranged continuously with the lower parts of the swing vanes 14 faces the inflow port from a runner boss 17 formed integrally with the runner fittedly connected to the drive shaft 31 of a motor. The swing vanes radially connect the runner boss 17 to an outside arc barrier wall and are vertically provided on the upper side disk bottom surface of a truncated reverse conical-shaped lower surface tapered part. Flow holes 18 in proximity to the runner boss are drilled in a plurality of arc-shaped compartments formed of the swing vanes. Radial split groove flow passages are connected continuously with the upper part of rather short auxiliary vanes connected to the arc barrier wall and vertically installed on the disk bottom surface, and vertical split grooves are connected continuously to the outer end thereof so as to form the arc barrier wall at the middle position of the swing vanes.
TANABE KAZUICHI
CHIBA YASUTSUNE
KANEIWA HIDEO
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