United Technologies Corporation

David L Chapski

Gerald P Dyer

Charles F Stearns

Kenneth F Vosseller

Mark R Tardif

According to the present invention, a fuel control has an electronic primary control for scheduling a flow of fuel to an engine in a primary mode and hydromechanical secondary control for scheduling the flow of fuel to the engine in a backup mode. The fuel control also has a tracking piston and link whose position is responsive to the HMU during the operation of the electronic primary control. The tracking piston and link effectively changes the power lever angle sensed by the HMU so that in the event of a transfer of control from the electronic primary control to the HMU, changes in the scheduled fuel flow to the engine are minimized.

Thrust bump system for fuel controls

Fuel flow to a gas turbine engine is controlled in response to power lever position and CDP. Fuel is supplied to the engine through three fuel flow regulating circuits which are in parallel. In one of these circuits there is a valve which establishes a minimum fuel flow which decreases with increasing power lever advance. In a second circuit there is a valve which modifies fuel flow in response to CDP. In a third circuit there is a valve which modifies fuel flow in response to CDP and receives fuel from a valve which opens with increasing power lever advance. The fuel control system includes a low power sensitive torque motor which may be activated to increase the pressure drop across the three circuits whose flow thus increases proportionally. Normal engine operation is obtainable without the use of the torque motor which provides an interface to an electronic control unit which senses various engine and ambient parameters and activates the torque motor in order to modify fuel flow accordingly.

Growing community of inventors

Enfield, CT, United States of America

David L Chapski