Control system for a multi-piston pump with solenoid valves for the

Abstract

A multi-piston pump is provided which uses microprocessor controlled check all valves to control flow rate of a fluid at the pump's outlet port. The pump includes nine cylindrical shaped chambers and associated reciprocating pistons which are driven by a cam attached to a shaft. The pump's shaft is coupled to the shaft of a motor which, in turn, drives the pump's shaft and cam resulting in a fluid, such as seawater, filling each of the nine chambers and then having the fluid forced from the chamber by the movement of its associated piston from bottom dead center to top dead center. A pressure transducer which monitors the pressure at the pump's outlet port and a shaft encoder which monitors the angular position of the pump's shaft respectively provide analog signals indicative of the pump's outlet port's pressure and the shaft's angular position. A microprocessor receives these analog signals in a digital form, processes the signals and provides digital pulse signals to either extend or retract the rod of nine solenoids depending upon the pressure at the pump's outlet port. Each of the nine solenoid rods when extended engage a check ball valve within one of the pumps nine inlet passageways allowing the passageway to remain open when the associated reciprocating piston is in a pumping stroke. This allows seawater to be discharged through the inlet passageway maintaining fluid flow at the outlet port at a pressure level which is commensurate with the intended use of the pump.