The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 15, 2000
Filed:
Dec. 04, 1998
Daniel J McLevige, Davis, IL (US);
Woodward Governor Company, Rockford, IL (US);
Abstract
A variable displacement pump fuel metering system wherein an electrohydraulic servo-valve powers a pump actuator to control pump displacement and variably bypasses fuel as an integrally related function to improve flow dynamics. The electrohydraulic servo-valve withdraws fuel from the pump output flow to drive the pump actuator and thereby control the displacement of the pump. The amount of bypassed is inversely proportional to the amount of fuel used to drive the actuator so that metered flow is maintained when an increase in pump output is demanded. The variable displacement pump may also meter flow in the downstream manifold. The electrohydraulic servo-valve is electrically controlled in a closed loop circuit with a flow sensing valve providing the feedback to an electronic engine controller. The electronic controller directly controls the electrohydraulic servo-valve.