A compressor disc for a compressor of a gas turbine engine includes a circumferentially extending groove for receiving blade roots of a plurality of compressor blades. The circumferentially extending groove includes a planar surface offset into the groove.

An actuation assembly for a variable pitch fan for a gas turbine engine is provided. The actuation assembly generally includes a plurality of fan blades, a scheduling ring, and a plurality of linkage arms. The plurality of fan blades are rotatably coupled to a disk and extend radially therefrom. The scheduling ring is rotatable relative to the disk and has a plurality of slots. Each of the plurality of linkage arms are operatively coupled to one of the plurality of fan blades and to one of the plurality of slots. Each of the plurality of fan blades rotate according to a blade pitch schedule defined by the slot to which it is operatively coupled, and at least two of the plurality of slots define different blade pitch schedules.

A variable pitch fan assembly includes a plurality of rotating trunnion assemblies, a plurality of counterweight assemblies, a first unison ring gear engaged with the trunnion assemblies, and a second unison ring member that restricts out of synch movement of the counterweights relative to each other.

An aerofoil body for a gas turbine engine is provided. The aerofoil body has leading and trailing edge portions, wherein one of the leading and trailing edge portions is a morphable edge portion having a composite layer structure. The aerofoil body further has a non-morphing central portion which forms pressure and suction surfaces of the aerofoil body between the leading and trailing edge portions. The composite layer structure includes a return spring, one or more shape memory alloy layers, and a flexible cover for the return spring and the one or more shape memory alloy layers. The flexible cover defines pressure and suction surfaces of the aerofoil body at the morphable edge portion. The one or more shape memory alloy layers are electrically heatable to deform the layers against the resistance of the return spring, and thereby alter the pitch of the aerofoil body at the morphable edge portion.

An actuator system including a harmonic drive operable to drive a variable vane system of a gas turbine engine.

An actuator system including a harmonic drive operable to drive a variable vane system of a gas turbine engine.

A turbomachine module with a longitudinal axis, the module comprising: a rotary casing rotatable around the longitudinal axis and arranged to carry a propeller provided with a plurality of blades; a system for changing the pitch of the blades of the propeller comprising: a control, and a mechanism for varying the pitch of the blades of the propeller connecting these blades to the control, wherein the control comprises a rotary actuator comprising a control body and a reference body which is integral with the rotary casing, and wherein the mechanism for varying the pitch comprises a synchronization ring which is driven in rotation around the longitudinal axis by the control body and which is guided in rotation on the rotary casing, the synchronization ring being connected to the blades.

A device for controlling positioning of variable-geometry equipment of a turbomachine, including a computer, an actuator of variable geometry driven by the computer, and a drive train, the actuator including moving parts including a sensor for measuring its elongation, the drive train being connected at one of its ends to a point of attachment of the moving parts and at another end to a point of attachment of the equipment, the point of attachment moving under action of the actuator along a travel limited by an end stop and the drive train being elastically deformable under the action of the actuator when the point of attachment is against the end stop. An elongation instruction supplied by the computer to the moving parts is defined as a difference with respect to the value of the elongation of the moving parts that corresponds to contact between the point of attachment and the end stop.

An actuation system is provided for varying the pitch of the blades of a variable pitch fan or propeller. The actuation system includes a first actuator and a second actuator. The actuation system further includes a first linkage which operably connects the first actuator to the blades such that operation of the first actuator varies the pitch of the blades via the first linkage. The actuation system further includes a second linkage which operably connects the second actuator to the first actuator such that operation of the second actuator varies the pitch of the blades by series connection of the second linkage to the first linkage.

A gas turbine engine according to an example of the present disclosure includes, among other things, a fan including a plurality of fan blades rotatable about an engine axis. Each of the fan blades have a leading edge and rotate about a fan blade axis. A method of operating a gas turbine engine is also disclosed.