Rotary, self-priming, liquip pump, and an impellers and shaft assembly therefor, and a flexible-impeller pump assembly

摘要

A pump housing has a plurality of chambers formed therein, and a shaft journaled within, the shaft having impellers keyed thereto. Each chamber has one of the impellers disposed therein. One of the impellers is the primary liquid-working element, and has rigid vanes. The vanes are generously spaced apart from the enclosing chamber walls. A second impeller has flexible vanes, and serves as a priming element; it has an intimate fit in its chamber and cooperates with an outlet flapper valve to create a negative pressure in the liquid inlet. Consequently, the pump can self-prime even when absolutely dry.