Pump including integral reservoirs for permitting dry run of pump

Abstract

A pump having a housing with an integral fluid reservoir and flexible end plates to permit the pump to be run dry for an extended period of time. A pair of reservoirs are provided, one each side of a pumping chamber. These reservoirs are in fluid communication with the pumping chamber via openings provided through the end plates of the pumping chamber and slots in the impeller hub. When the pump is run dry, fluid stored in these reservoirs is permitted to be released into the pumping chamber to provide a lubrication between the impeller and the chamber walls, thus reducing friction. The chamber end plates are thin and flexible. These end plates can bow outwardly due to the impeller expanding from increased heat when the pump is run dry, and thus reduce friction with the impeller. Accordingly, the pump can be run dry for an extended period of time without damaging or destroying the pump impeller. The end plate openings are preferably provided adjacent the impeller hub such that fluid is released closely proximate the impeller hub. An flexible impeller is preferred, but the present invention is suited for sliding vane and roller type impellers as well.

Dependencies are inferred from the claim text.