초록 ▼

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 fl

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.

대표청구항 ▼

[ What is claimed is:] [1.] A fuel metering system for controlling fuel flow to a combustion chamber, comprising:a variable displacement pump adapted to provide a pumped flow of fuel to the combustion chamber;an actuator connected to the pump and drivable between multiple positions to control the di

[ What is claimed is:] [1.] A fuel metering system for controlling fuel flow to a combustion chamber, comprising:a variable displacement pump adapted to provide a pumped flow of fuel to the combustion chamber;an actuator connected to the pump and drivable between multiple positions to control the displacement of the variable displacement pump;an actuator control valve operated on fuel, the actuator control valve having an inlet adapted to draw fuel from the pumped flow, a working output adapted to drive the actuator, and a fuel bypass, the actuator control valve including a selectively positioned valve operator therein for controlling fuel flow from the inlet to both the working output and the fuel bypass, the position of the valve operator controlling the fuel flow rate through the fuel bypass as an inversely related function of the fuel flow rate through the working output.