Patent ID: 8182200
Filing Date: 2012-05-22
Classification: F04D

Abstract:
1. A self-priming centrifugal pump comprising: a body that has chamber walls that form a cavity with an upstream pumping chamber that has an inlet and a downstream priming chamber that has an outlet; a centrifugal impeller lying in said upstream chamber for pumping liquid from said inlet toward said outlet; a diaphragm that is positioned along said downstream chamber and that is reciprocatable to repeatedly compress and expand said downstream chamber to prime the pump; valve means coupled to said downstream chamber for allowing fluid flow only out of said outlet when the pump is being primed; drive means including a mechanism for reciprocating the diaphragm during priming of the pump and for automatically not reciprocating the diaphragm in response to a pressure increase in the downstream chamber that indicates that the pump has been primed.