An integral flapper and nozzle structure for a servo valve assembly whereby the flapper, orifices and nozzles are formed by sheets of metal formed into a single component.

A servo valve includes: a fluid transfer valve assembly comprising a supply port and a control port (P.sub.A, P.sub.B); a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal; and a drive means configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The drive means comprises an elongate member arranged to rotate in response to the control signal. The elongate member has a cam profile in the fluid flow path such as to vary the pressure acting on the ends of the spool as the cam profile rotates.

The disclosure relates to a flight control system comprising at least one hydraulic servo actuator, wherein the servo actuator includes a two-stage electrohydraulic servo valve, wherein the servo valve comprises a pilot stage in which the control current is translated into a hydraulic control pressure, and a power stage in which a valve slide is moved in response to the control pressure in order to adjust the throughflow direction and throughflow cross-section of the valve. The disclosure furthermore relates to an aircraft comprising such a flight control system.

A single stage flapper type servovalve comprises a valve housing comprising a bore, a pair of opposed nozzles arranged in the bore and a flapper element arranged between the pair of nozzles. The valve housing further comprises a plurality of fluid ports for communicating a working fluid to and from the nozzles and in fluid communication with the housing bore. The valve housing and the nozzles are both made from a stainless steel material.

The disclosure relates to a flight control system comprising at least one hydraulic servo actuator, wherein the servo actuator includes a two-stage electrohydraulic servo valve, wherein the servo valve comprises a pilot stage in which the control current is translated into a hydraulic control pressure, and a power stage in which a valve slide is moved in response to the control pressure in order to adjust the throughflow direction and throughflow cross-section of the valve. The disclosure furthermore relates to an aircraft comprising such a flight control system.

A nozzle for a servo valve comprises an annular body defining an outer circumferential surface and an inner circumferential surface of the nozzle. An annular groove is disposed around the circumference of the annular body in the outer circumferential surface. A nozzle assembly (N) for a servo valve comprises the nozzle and a nozzle housing having a nozzle cavity defined by an inner circumferential cavity surface. The nozzle housing has an annular groove disposed around the circumference of the nozzle cavity in the inner circumferential cavity surface. The nozzle is received within the nozzle cavity such that the annular grooves in the nozzle and the nozzle housing are in fluid communication with each other.

There is provided an apparatus comprising a torque motor comprising a spring, armature, flapper assembly (“SAFA”), a body, wherein the spring, armature, flapper assembly is mounted onto the body, and a cap enclosing the spring, armature, flapper assembly. One or more cooling passages are provided within the body and are configured to receive cooling air and direct the cooling air onto the spring, armature, flapper assembly of the torque motor.

A valving system has an actuator member connected to move with an actuator piston and change the position of a valve member. There is a smaller face fluid chamber acting on a small area piston face, and a larger face fluid chamber acting on a larger face of the actuator piston. The torque motor has an armature and a flapper caused to move by current received at the armature. The flapper moves between two fluid ports to control the pressure in the larger face chamber. The flapper further has a positioning extension engaging a first feedback spring operable between it and a forward face of the actuator piston and providing a spring force in combination with a spring force from the positioning extension. A control is operable to provide current to the armature to control the fluid received in the larger face chamber. The controller is programmed to associate the current supplied to the armature to an actual position of the valve member. A method is also disclosed.

A servo valve comprises a member disposed in a cavity and axially-moveable therein. The member includes first and second sections, a central section located between the first and second sections and first and second transition sections respectively between the first and second sections and the central section, forming respective first and second outer surfaces angled relative to the axis (X). At least one of the transition sections comprises a non-circular cross-section having a concave portion forming at least part of the respective first and second surfaces and being at least partially aligned with and facing the respective first or second nozzle opening such that rotating the member in said cavity varies the level of obstruction of the first or second nozzle openings by the first or second outer surfaces.

A servovalve includes a supply port and a control port; a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal and a drive assembly configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow; wherein the drive assembly comprises a first fluid channel providing a flow path for fluid from the supply port to a first end of the spool and provided with a first flow control orifice. The assembly also includes a second fluid channel providing a rotating element provided with a cam profile located between the first flow control orifice and the second flow control orifice. The assembly also includes drive means arranged to rotate the rotating element.