Abstract: 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.

Abstract: A servo valve comprises a valve housing, a cavity formed in the valve housing and defining a longitudinal axis (X), and a member disposed in the cavity and axially-moveable therein, wherein the member comprises a portion with first and second cylindrical sections having a first diameter (R1, R2), a central section located between the first and second cylindrical sections and having a second diameter (R3), and first and second frusto-conical sections connecting the first and second sections to the central section and forming respective first and second frusto-conical surfaces. A plurality of ports, each form a fluid passage through the valve housing and have first and second nozzles with first and second nozzle openings.