James R Massey

US Patent:

54565812, Oct 10, 1995

Filed:

Aug 12, 1994

Appl. No.:

8/290669

Inventors:

Gregory R. Jokela - Oakview CA
Roman Kruchowy - Somis CA
James Massey - Ventura CA

Assignee:

The United States of America as represented by the Secretary of the Navy - Washington DC

International Classification:

F04B 4900
F04B 1900
F04B 2708
F04B 126

US Classification:

417282

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.