To securely operate a flow switch arranged outside of a discharge port, and to eliminate the foreign matters caught between a partitioning plate and a rubber pad.
A self-priming pump 1 is formed of a pump unit 6 formed by fixing a first case 1 as a tank chamber 18 provided with a suction port 23 for sucking the liquid and a discharge port for discharging the liquid and a second case 3 as a pump chamber 19 while pinching a partitioning plate 4 and a rubber pad 5, and a driving motor 9 for driving an impeller 10 housed in the pump chamber 19. When the impeller 10 is rotated, the liquid is pumped through a self-priming process that the air and the liquid are agitated in the pump 6 while gradually discharging the air. The discharge port is formed with a flow aligning rib for aligning the liquid to the straight flow for discharge. The rubber pad 5 is formed with a discharge port for discharging the caught foreign matters.
HOSHINA TETSUO
SUGIHARA HIROSHI
YUMITA YUKINOBU
