Piezoelectric ring bender servo valve assembly for aircraft flight control actuation and fuel control systems

A piezoelectric ring bender servo valve assembly, the assembly comprising:

• a valve housing, the valve housing being defined by a passageway, the passageway being operable to carry a fluid;
• a pair of nozzles, the nozzles being in communication with the fluid, the nozzles terminating at a pair of orifices;
• a pair of piezoelectric members disposed adjacent to the nozzles, the piezoelectric members being operable to move to an open position away from the nozzles to enable an increase in flowage of the fluid through the nozzles, the piezoelectric members being operable to return towards the nozzles to enable a decrease flowage of the fluid through the nozzles;
• a spool valve operationally connected to the piezoelectric members, the spool valve being disposed in at least one spool position to regulate flow of the fluid through the passageway, the pair of piezoelectric members directly controlling operation of the spool position;
• a linear position sensing device operationally connected to the spool valve, the linear positioning device determining the spool position of the spool valve, the linear positioning device providing feedback about the spool position;
• a valve controller operationally connected to the linear position sensing device, the valve controller receiving the feedback from the linear position sensing device, whereby based on the feedback the valve controller transmitting an electrical command signal to a piezo driver to move the spool valve until the spool position is traversed to a command position;
• the piezo driver generating a voltage applied to the pair of piezo electric members based on the electrical command signal from the valve controller to move the pair of piezoelectric members;
• wherein the pair of nozzles and the pair of piezoelectric members together constituting a pair of variable restrictors, and the variable restrictors generating a pressure difference across the spool valve;
• a pair of flow restricting orifices connected to a fluid power supply inlet port, wherein each of the flow restricting orifices is arranged in the valve housing upstream of a respective pilot chamber of the spool valve and in parallel to a respective fluid power supply channel that is located upstream of the spool valve;
• and
• wherein the spool valve controls flow through each of the fluid power supply channels.