Abstract: A servo valve comprising: a fluid transfer valve assembly includes: a housing having channel therethrough fluidly connecting a supply port, a return port and a control port formed in the housing; a moveable valve spool located within the channel and arranged to regulate flow of fluid between the supply port, the return port and 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. The valve spool comprises a first spool part and a second spool part and the drive assembly comprises a piezoelectric actuator positioned between the first and the second spool parts within the channel. Then when a control signal is applied to the piezoelectric actuator it causes extension or contraction of the first and second piezoelectric actuator elements.

Abstract: A fuel filter includes a manifold, a connector element, a filter bowl, a filter element, an inlet shutoff valve, an outlet shutoff valve, an inlet port, an inlet passage, an outlet port, an outlet passage and a relief valve in which the connector element is fixed to the manifold, and the filter bowl is reversibly fixed to the connector element, the connector element and the manifold define a chamber and the chamber is split into a second inlet chamber and a second outlet chamber by the relief valve. The filter bowl is adapted to reversibly receive the filter element and is so configured that when the filter element is located within the filter bowl and the filter bowl attached to the connection element, the filter element divides the space defined by the connector element and filter bowl into an inlet filter chamber and an outlet filter chamber.

Abstract: A fuel filter includes a manifold, a connector element, a filter bowl, a filter element, a shutoff valve, an inlet port, an inlet passage, an outlet port, an outlet passage and a relief valve in which the connector element is fixed to the manifold, and the filter bowl is reversibly fixed to the connector element, the filter bowl is adapted to reversibly receive the filter element and is so configured that when the filter element is located within the filter bowl and the filter bowl attached to the connection element the filter element divides the space defined by the connector element and filter bowl into an inlet filter chamber and an outlet filter chamber, the inlet port is incorporated in the manifold, and the inlet port and inlet filter chamber are in fluid communication via the inlet passage, the outlet port is incorporated in the manifold.

Abstract: A servo valve includes a fluid transfer valve assembly comprising a valve body having a supply port and a control port (C1). The valve body has first and second nozzles and a drive member therebetween, arranged to regulate flow of fluid from the supply port to the control port in response to a control signal. The assembly also includes a drive assembly comprising a magnetic coil and a core passing through the coil and configured to move axially with respect to the coil when the coil is powered by a current dependent on the control signal, the drive assembly arranged to move the drive member relative to the first and second nozzles in response to the control signal.

Abstract: A servo valve assembly includes a first nozzle opposing a second nozzle and a shaft positioned in the gap between the first and second nozzles. The first and second nozzles are spaced apart by a gap and each nozzle has an outlet opening. The shaft defines a diameter (D) and a circumferential surface and is rotatable about an axis of rotation (R-R). The shaft defines first and second reduced radial portions around its circumferential surface, and the first and second reduced radial portions are in fluid communication with the first and second nozzle outlet openings, respectively. The shaft is configured to rotate between a first position where the first nozzle outlet opening is more occluded by the shaft circumferential surface than the second nozzle outlet opening, and a second position where the first nozzle outlet opening is less occluded by the shaft circumferential surface than the second nozzle outlet opening.

Abstract: A servo valve includes a fluid transfer valve assembly comprising a supply port and a control port; a 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 move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The drive means is arranged to rotate the spool relative to the fluid transfer assembly, the spool provided with openings arranged to selectively align with or block flow channels in the fluid transfer assembly according to the direction and degree of rotation of the spool.

Abstract: A servo valve assembly includes a housing defining a cylindrical cavity having a central axis, and a spool disposed in the cavity and co-axially aligned with the central axis. A pair of transition portions define opposing conical cavity surfaces each connect a respective one of first and second cylindrical cavity portions with a third cylindrical cavity portion. The spool comprises a pair of blocking members projecting radially, and each of the blocking members defines a conical blocking surface opposing a respective one of the conical cavity surfaces to define a fluid flow passage therebetween. A cone angle of each conical blocking surface relative to the central is equal to a cone angle of the opposing conical cavity surface relative to the central axis. The spool is moveable along the central axis to vary a flow area of the flow passages between the conical blocking surfaces and the conical cavity surfaces.

Abstract: A servo valve comprises a valve housing, a cavity formed in the valve housing and a member disposed in the cavity and axially-moveable therein. The servo valve further comprises a piezoelectric actuator configured to axially move the member, relative to the valve housing, between first and second axial positions.

Abstract: 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.

Abstract: A servo valve includes a fluid transfer valve assembly comprising a supply port and a control port; a 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 move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The drive means is arranged to rotate the spool relative to the fluid transfer assembly, the spool provided with openings arranged to selectively align with or block flow channels in the fluid transfer assembly according to the direction and degree of rotation of the spool.

Abstract: A fuel filter includes a manifold, a connector element, a filter bowl, a filter element, a shutoff valve, an inlet port, an inlet passage, an outlet port, an outlet passage and a relief valve in which the connector element is fixed to the manifold, and the filter bowl is reversibly fixed to the connector element, the filter bowl is adapted to reversibly receive the filter element and is so configured that when the filter element is located within the filter bowl and the filter bowl attached to the connection element the filter element divides the space defined by the connector element and filter bowl into an inlet filter chamber and an outlet filter chamber, the inlet port is incorporated in the manifold, and the inlet port and inlet filter chamber are in fluid communication via the inlet passage, the outlet port is incorporated in the manifold.

Abstract: A fuel filter is provided which comprises a manifold, a connector element, a filter bowl, a filter element, an inlet shutoff valve, an outlet shutoff valve, an inlet port, an inlet passage, an outlet port, an outlet passage and a relief valve in which the connector element is fixed to the manifold, and the filter bowl is reversibly fixed to the connector element. The filter bowl is adapted to reversibly receive the filter element and is so configured that when the filter element is located within the filter bowl and the filter bowl attached to the connection element the filter element divides the space defined by the connector element and filter bowl into an inlet filter chamber and an outlet filter chamber. The inlet port mouths through a surface of the manifold, and the inlet port and inlet filter chamber are in fluid communication via the inlet passage.

Abstract: A fuel filter is provided which includes a manifold, a connector element, a filter bowl, a filter element, an inlet shutoff valve, an outlet shutoff valve, an inlet port, an inlet passage, an outlet port, an outlet passage and a relief valve in which the connector element is fixed to the manifold, and the filter bowl is reversibly fixed to the connector element. The filter bowl is adapted to reversibly receive the filter element and is so configured that when the filter element is located within the filter bowl and the filter bowl attached to the connection element, the filter element divides the space defined by the connector element and filter bowl into an inlet filter chamber and an outlet filter chamber and the inlet port is incorporated in the manifold, and the inlet port and inlet filter chamber are in fluid communication via the inlet passage.

Abstract: A fuel filter includes a manifold, a connector element, a filter bowl, a filter element, an inlet shutoff valve, an outlet shutoff valve, an inlet port, an inlet passage, an outlet port, an outlet passage and a relief valve in which the connector element is fixed to the manifold, and the filter bowl is reversibly fixed to the connector element, the connector element and the manifold define a chamber and the chamber is split into a second inlet chamber and a second outlet chamber by the relief valve. The filter bowl is adapted to reversibly receive the filter element and is so configured that when the filter element is located within the filter bowl and the filter bowl attached to the connection element, the filter element divides the space defined by the connector element and filter bowl into an inlet filter chamber and an outlet filter chamber.

Abstract: A servo valve includes a valve housing, a cavity formed in the valve housing defining an axis (X) and an axially moveable member disposed in the cavity. At least one actuator is configured to axially move the member within the cavity and a spring is arranged between first and second axial ends of the valve housing. A channel is formed within the cavity and a plurality of ports each forming a fluid passage through the valve housing in fluid communication with a spool and with the channel. The plurality of ports comprise first and second nozzles with nozzle openings, wherein in a first axial position of the member the first nozzle opening is at least substantially obstructed, and in a second axial position of the member the second nozzle opening is at least substantially obstructed, the member controlling fluid between the spool and the channel.

Abstract: A servo valve includes a valve housing, a cavity formed in the valve housing defining an axis (X) and an axially moveable member disposed in the cavity. The member comprises flat surfaces parallel to the axis (X). A channel is formed within the cavity and a plurality of ports each forming a fluid passage through the valve housing in fluid communication with a spool and with the channel. The plurality of ports include first and second nozzles with nozzle openings, wherein in a first axial position of the member the first nozzle opening is at least substantially obstructed by the first flat surface, and in a second axial position of the member the second nozzle opening is at least substantially obstructed by the second surface, the member controlling fluid between the spool and the channel.

Abstract: A servo valve assembly includes a first nozzle opposing a second nozzle and a shaft positioned in the gap between the first and second nozzles. The first and second nozzles are spaced apart by a gap and each nozzle has an outlet opening. The shaft defines a diameter (D) and a circumferential surface and is rotatable about an axis of rotation (R-R). The shaft defines first and second reduced radial portions around its circumferential surface, and the first and second reduced radial portions are in fluid communication with the first and second nozzle outlet openings, respectively. The shaft is configured to rotate between a first position where the first nozzle outlet opening is more occluded by the shaft circumferential surface than the second nozzle outlet opening, and a second position where the first nozzle outlet opening is less occluded by the shaft circumferential surface than the second nozzle outlet opening.

Abstract: A servo valve assembly includes a housing defining a cylindrical cavity having a central axis, and a spool disposed in the cavity and co-axially aligned with the central axis. A pair of transition portions define opposing conical cavity surfaces each connect a respective one of first and second cylindrical cavity portions with a third cylindrical cavity portion. The spool comprises a pair of blocking members projecting radially, and each of the blocking members defines a conical blocking surface opposing a respective one of the conical cavity surfaces to define a fluid flow passage therebetween. A cone angle of each conical blocking surface relative to the central is equal to a cone angle of the opposing conical cavity surface relative to the central axis. The spool is moveable along the central axis to vary a flow area of the flow passages between the conical blocking surfaces and the conical cavity surfaces.

Abstract: A servo valve includes a valve housing, a cavity formed in the valve housing defining an axis (X) and an axially moveable member disposed in the cavity. The member comprises flat surfaces parallel to the axis (X). A channel is formed within the cavity and a plurality of ports each forming a fluid passage through the valve housing in fluid communication with a spool and with the channel. The plurality of ports include first and second nozzles with nozzle openings, wherein in a first axial position of the member the first nozzle opening is at least substantially obstructed by the first flat surface, and in a second axial position of the member the second nozzle opening is at least substantially obstructed by the second surface, the member controlling fluid between the spool and the channel.

Abstract: A servo valve includes a valve housing, a cavity formed in the valve housing defining an axis (X) and an axially moveable member disposed in the cavity. At least one actuator is configured to axially move the member within the cavity and a spring is arranged between first and second axial ends of the valve housing. A channel is formed within the cavity and a plurality of ports each forming a fluid passage through the valve housing in fluid communication with a spool and with the channel. The plurality of ports comprise first and second nozzles with nozzle openings, wherein in a first axial position of the member the first nozzle opening is at least substantially obstructed, and in a second axial position of the member the second nozzle opening is at least substantially obstructed, the member controlling fluid between the spool and the channel.