On-demand dual variable displacement positive displacement pumping system

A fuel delivery system for supplying fuel to a jet turbine engine, the fuel delivery system comprising:

• a fuel line connected to a fuel nozzle;
• a first pump assembly comprising:
• a first pump with a first outlet fluidically connected to the fuel line;
• a first hydraulic actuator mechanically coupled to the first pump;
• a first linear variable differential transducer attached to the first hydraulic actuator;
• and
• a first check valve downstream from the first pump, wherein the first check valve prevents backflow into the first pumping assembly;
• a second pump assembly comprising:
• a second pump with a second outlet fluidically connected to the fuel line;
• a second hydraulic actuator mechanically coupled to the second pump;
• a second linear variable differential transducer attached to the second hydraulic actuator;
• and
• a second check valve downstream from the second pump, wherein the second check valve prevents backflow into the second pumping assembly;
• an electrohydraulic servo valve hydraulically connected to the first and second hydraulic actuators;
• and
• an electronic engine controller in communication with the first linear variable differential transducer, the second linear variable differential transducer, and the electrohydraulic servo valve.

A method of controlling a pumping system for supplying fuel to a jet turbine engine, the method comprising:

• sensing by a first position sensor a linear displacement of a first actuator that is mechanically coupled to a displacement mechanism of a first variable displacement pump;
• sensing by a second position sensor a second linear displacement of a second actuator that is mechanically coupled to a second displacement mechanism of a second variable displacement pump;
• receiving the linear displacement of the first actuator and the second linear displacement of the second actuator by an electronic engine controller;
• sending a current from the electronic engine controller to a servo valve, wherein the servo valve is hydraulically connected to the first actuator and the second actuator;
• and
• communicating hydraulically by the servo valve with at least one of the first and second actuators in response to the current sent to the servo valve,
• wherein the first actuator comprises a linear variable differential transducer in communication with the electronic engine controller and configured to measure the linear displacement of the first actuator, and wherein the second actuator comprises a second linear variable differential transducer in communication with the electronic engine controller and configured to measure the linear displacement of the second actuator.