Abstract: A filter assembly for a servo valve that includes a first fluid nozzle defining a first fluid passage therethrough between a first fluid inlet and a first fluid outlet and a second fluid nozzle defining a second fluid passage therethrough between a second fluid inlet and a second fluid outlet. The first and second fluid nozzles arranged in end to end abutment with each other to form a tubular fluid nozzle unit in which the first and second fluid inlets are adjacent each other, and the first and second fluid passages align to form a common fluid passage through the tubular fluid nozzle unit. The first fluid outlet is at a first end of the tubular fluid nozzle unit and the second fluid passage being at a second, end of the tubular fluid nozzle unit.

Abstract: 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.

Abstract: 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.

Abstract: A filter assembly for a servo valve. The filter assembly has a filter body defining a chamber; a first end cap having a first fluid outlet at a first end of the filter body and a second end cap having a second fluid outlet at a second end of the filter body. A flow restrictor restricts fluid flow between the filter body and each of the first and second fluid outlets. A spacer in the chamber spaces the first end cap from the second end cap.

Abstract: A torsion bridge for use in a servovalve includes a body extending along and adapted to rotate about a first axis; a passage extending through the body along a second axis substantially perpendicular to the first axis, the passage defining a first cylindrical surface having a radius R1; an annular groove formed in the first cylindrical surface. The annular groove includes: a second cylindrical surface extending substantially in the direction of the second axis, the second cylindrical surface having first and second ends and a radius R2, where R2 is greater than R1; a first annular surface joining the first cylindrical surface to the first end of the second cylindrical surface; and a second annular surface joining the second end of the second cylindrical surface to the first cylindrical surface.

Abstract: A valve body for a servovalve is provided comprising: a first surface adapted to extend parallel and adjacent to a substantially flat pole piece surface of a pole piece in use; and attachment features provided on the first surface for attaching the valve body to the pole piece in use, wherein the first surface is contoured such that, in use, an area of the first surface surrounding the attachment features is in contact with the substantially flat pole piece surface and an area of the first surface removed from the attachment features is not in contact with the substantially flat pole piece surface.

Abstract: A nozzle housing for a servo valve includes a circumferential wall defining a return passage extending along a longitudinal axis (A) for holding a return nozzle, the return passage having an opening for fluid communication with a spool valve and a return port for fluid communication with atmosphere, a first plate extending across the return passage, the first plate engaged with the circumferential wall and disposed between the opening and the return port, and a second plate extending across the return passage. The second plate engages with the circumferential wall and disposed between the first plate and the return port, the first plate has at least one first aperture, and the second plate has at least one second aperture that is misaligned with the at least one first aperture such that there is no linear axial flow path between the return port and the opening.

Abstract: 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.

Abstract: An assembly for use in a servovalve is provided. The assembly includes: a moveable member having a first end and a second end, the moveable member extending along a longitudinal axis (A?-A?) from the first end to the second end; and a torsion bridge, the torsion bridge extending around the moveable member at the first end thereof, and being adapted to rotate about a rotation axis (Ar), wherein the rotation axis (Ar) extends perpendicular to the longitudinal axis (A?-A?), and wherein the moveable member and the torsion bridge form an integral part having a planar surface adapted to receive a planar surface of an armature.

Abstract: A nozzle housing for a servo valve includes a circumferential wall defining a return passage extending along a longitudinal axis (A) for holding a return nozzle, the return passage having an opening for fluid communication with a spool valve and a return port for fluid communication with atmosphere, a first plate extending across the return passage, the first plate engaged with the circumferential wall and disposed between the opening and the return port, and a second plate extending across the return passage. The second plate engages with the circumferential wall and disposed between the first plate and the return port, the first plate has at least one first aperture, and the second plate has at least one second aperture that is misaligned with the at least one first aperture such that there is no linear axial flow path between the return port and the opening.

Abstract: 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.

Abstract: A valve body for a servovalve is provided comprising: a first surface adapted to extend parallel and adjacent to a substantially flat pole piece surface of a pole piece in use; and attachment features provided on the first surface for attaching the valve body to the pole piece in use, wherein the first surface is contoured such that, in use, an area of the first surface surrounding the attachment features is in contact with the substantially flat pole piece surface and an area of the first surface removed from the attachment features is not in contact with the substantially flat pole piece surface.

Abstract: A torsion bridge for use in a servovalve includes a body extending along and adapted to rotate about a first axis; a passage extending through the body along a second axis substantially perpendicular to the first axis, the passage defining a first cylindrical surface having a radius R1; an annular groove formed in the first cylindrical surface. The annular groove includes: a second cylindrical surface extending substantially in the direction of the second axis, the second cylindrical surface having first and second ends and a radius R2, where R2 is greater than R1; a first annular surface joining the first cylindrical surface to the first end of the second cylindrical surface; and a second annular surface joining the second end of the second cylindrical surface to the first cylindrical surface.

Abstract: An improved torque motor for use in a servovalve is described herein, comprising: first and second pole pieces, having a C-shaped cross-section comprising a ring shaped section extending in a first plane with first and second portions extending perpendicularly away from said plane and inwards towards an armature plate. The perpendicularly extending portions are detachable from and attachable to the ring-shaped section of the pole pieces to allow for easier calibration and adjustment of the air gaps between the pole pieces and the armature plate positioned there between.