A gas turbine engine includes a fan having a plurality of fan blades configured to rotate about a central axis of the gas turbine engine. Each fan blade is configured to pivot about a pitch axis that extends radially away from the central axis to vary a pitch of the fan blade.

Assembly for a turbomachine blade, comprising: a fastener (9) defining a pocket (10) for receiving a blade root (11), and comprising two flanks defining between them a passage leading into the pocket (10) and forming stops preventing the root (11) from exiting from the pocket (10) via the passage, a shim (26a, 26b) adapted to be received in the pocket (10) with the root (11), the shim (26a, 26b) having a first support surface (28a, 28b) to bear on the root (11) and a second support surface (30a, 30b) opposite the first support surface (28a, 28b) to bear against the fastener (9), the support surfaces being fixed relative to each other and oriented such that movement of the shim (26a, 26b) in the pocket (10) relative to the fastener (9) varies the value of force exerted by the shim (26a, 26b) on the root (11).

A gas turbine engine includes a turbomachine comprising a compressor section, a combustion section, and a turbine section arranged in serial flow order. A fan defining a fan axis and comprising a plurality of fan blades is rotatable about the fan axis. A pitch change mechanism is operable with the plurality of fan blades to control a pitch of the plurality of fan blades. A counterweight is connected to each respective fan blade. A spring mechanism is operably associated with each fan blade of the plurality of fan blades to create a spring twisting moment on the respective fan blade that is counter to a centrifugal twisting moment of the respective fan blade.

The present invention relates to a fan rotor with variable pitch blades, comprising a rotor disc, equipped at its periphery with a plurality of rotary fasteners (16), each fastener (16) comprising a cell (17) for receiving the root (150) of a blade (15). This rotor is characterised in that an elongated wedge (2) and a prestressing rod (3) with at least one cam (33) are also arranged in each cell (17), the bottom of the cell (17) comprising as many retraction cavities (173) as the rod (3) comprises cams (33), in that the prestressing rod (3) is interposed between the wedge (2) and the bottom (171) of the cell (17), so that said cam (33) is facing a corresponding retraction cavity (173) and in that the prestressing rod (3) can rotate about its longitudinal axis (X2-X2), between a rest position, in which the cam (33) is housed in the retraction cavity (173), and an armed position, in which the cam (33) exerts a radial pressure on the central region (22) of the wedge (2) so as to move the wedge (2) towards the blade root (150).

A gas turbine engine may have a fan section that includes a variable pitch mechanism for changing the pitch of fan blades. The gas turbine engine may include a fan hub that is rotatable about an engine central longitudinal axis of the gas turbine engine and a blade receiver that is for holding a fan blade and that is rotatably coupled to the fan hub and may be rotatable about a radial axis of the gas turbine engine. The gas turbine engine may include a spring element disposed between the fan hub and the blade receiver to bias the blade receiver radially outward and an annular retaining ring may be disposed around the radial axis and between the fan hub and the blade receiver to limit radially outward movement of the blade receiver to prevent the blade receiver from decoupling and disengaging from the fan hub.

A variable vane system includes a unison ring driven by a harmonic drive. A multiple of pins extend from the unison ring. A multiple of variable vanes are driven by the unison ring, each of the multiple of variable vanes connected to the unison ring through a respective drive arm with a slot that receives one of the multiple of pins to accommodate axial motion a support that extends from an engine case to support the unison ring and a multiple of rollers to support the unison ring.

A variable pitch fan for gas turbine engine is provided. The variable pitch fan includes a plurality of fan blades rotatably coupled to a disk and an actuation assembly for changing a pitch of each of the plurality of fan blades. The actuation assembly generally includes an actuation member operably connected to at least one of the plurality of fan blades and a pin. The pin is movable between a first position in which the pin is positioned at least partially in a channel defined in the actuation member, and a second position. The pin blocks movement of the actuation member relative to the pin past a range defined by the channel when in the first position. The actuation assembly further includes a retraction system for selectively engaging the pin in moving the pin from the first position to the second position.

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 feedback sensor system is provided. The feedback sensor system includes a first ring rotatable about an axial direction and a second ring also rotatable about the axial direction. The first ring includes one or more first ring features and the second ring includes one or more second ring features. The feedback sensor system also includes a sensor directed at the surface of the first ring for sensing a parameter influenced by the one or more first ring features and the one or more second ring features. The sensor may determine a position of the first ring relative to the second ring by sensing the parameter.

A gas turbine engine may have a blade receiver for holding a fan blade, wherein the blade receiver is rotatable about a radial axis of the gas turbine engine. The gas turbine engine may also include a variable pitch mechanism comprising an actuation arm. The gas turbine engine may also include a splined index ring disposed between the actuation arm of the variable pitch mechanism and the blade receiver. The splined index ring may include an outer spline and an inner spline.