| 摘要 |
PROBLEM TO BE SOLVED: To provide a self-priming pump shortened in air discharge time and reduced in size and weight as compared with a self-priming pump of a conventional structure by enhancing self-priming performance. SOLUTION: In this self-priming pump, a water storage space 40 for storing water at the time of stopping a pump is provided between a suction port 10a and an impeller 16. The water storage space 40 is formed into a volute shape continuously extending from the suction port 10a and gradually reducing cross-sectional area along a rotating direction of the pump, and is provided with a flow passage enlarging part 24 arranged to be inclined upward toward a discharge port 10b in the wake of a discharge volute 22 to store the impeller 16. A return flow passage 26 opening in the vicinity of a rear end of the discharge volute 22 or a part 25 of the flow passage enlarging part 24, going up after lowering up to a position below an axial center height of the pump, and opening toward the center of the impeller 16 at the axial center height position of the pump. A switching valve 42 is arranged in the return flow passage 26. COPYRIGHT: (C)2004,JPO
|
