A pitch actuation system for a turbomachine propeller, comprising an actuator with a movable portion configured to be connected to blades of the propeller in order to rotate them relative to the blade-pitch setting axes, wherein the actuator is an electromechanical actuator and comprises: blade-pitch control having a transmission screw rotated about an axis; a nut through which said transmission screw passes; and a member configured to engage with the blades in order to move the blades, wherein the nut is connected to the member via a decoupler configured such that a translational movement of the nut causes a translational movement of the member, but rotational movement of the member does not cause rotational movement of the nut.

A pitch actuation system for a turbomachine propeller, comprising an actuator with a movable portion configured to be connected to blades of the propeller in order to rotate them relative to the blade-pitch setting axes, wherein the actuator is an electromechanical actuator and comprises: blade-pitch control having a transmission screw rotated about an axis; a nut through which said transmission screw passes; and a member configured to engage with the blades in order to move the blades, wherein the nut is connected to the member via a decoupler configured such that a translational movement of the nut causes a translational movement of the member, but rotational movement of the member does not cause rotational movement of the nut.

A gas turbine engine including a core having in serial flow order a compressor, a combustor, and a turbinethe compressor, combustor, and turbine together defining a core air flowpath. The gas turbine engine additionally includes a fan section mechanically coupled to the core, the fan section including a plurality of fan blades, and each of the plurality fan blades defining a pitch axis. An actuation device is operable with the plurality fan blades for rotating the plurality fan blades about their respective pitch axes, the actuation device including an actuator located outward of the core air flowpath to, e.g., simplify the gas turbine engine.

A gas turbine engine including a core having in serial flow order a compressor, a combustor, and a turbinethe compressor, combustor, and turbine together defining a core air flowpath. The gas turbine engine additionally includes a fan section mechanically coupled to the core, the fan section including a plurality of fan blades, and each of the plurality fan blades defining a pitch axis. An actuation device is operable with the plurality fan blades for rotating the plurality fan blades about their respective pitch axes, the actuation device including an actuator located outward of the core air flowpath to, e.g., simplify the gas turbine engine.

A variable pitch fan assembly includes variable pitch fan blades circumscribed about engine centerline axis coupled to a drive shaft centered about the engine centerline axis. Each blade pivotable about pitch axis perpendicular to centerline axis and having blade turning lever connected thereto. One or more linear actuators non-rotatably mounted parallel to engine centerline axis and operably linked to fan blades for pivoting fan blades and connected to spider ring through thrust bearings for transmission of axial displacement of non-rotatable actuator rods of actuators while the fan blades are rotating. Spider arms extending away from spider ring towards blade roots and each spider arm connected to one of the turning levers. Turning levers may be connected and caromed to spider arms by pin and slot joint. Each spider arm may include joint pin disposed through joint slot of turning lever. Joint slot may be angled or curved.

A variable pitch fan assembly for an aero gas turbine engine that includes a row of fixed pitch blades in a core stream flow and a row of variable pitch blades in a bypass stream flow, and where a sync ring with a number of hydraulic actuators within a flow splitter of the fan stage is used to vary a pitch of each of the bypass stream flow blades. Hydraulic fluid lines pass through the shaft and through the fixed pitch fan blades into the hydraulic actuators to move the sync ring and vary a pitch of the variable pitch bypass flow fan blades.

A ram air turbine has turbine blades connected to rotate a transmission shaft. The transmission shaft is connected to drive a first gear which is engaged to drive a second gear. The second gear is connected to rotate an output shaft extending through a strut away from the transmission shaft. A governor arrangement is configured to change a pitch angle of the blades in response to speed, and includes counterweights acting on a spring in the governor arrangement. The governor spring is positioned on an opposed side of the strut relative to the turbine.

A ram air turbine has turbine blades connected to rotate a transmission shaft. The transmission shaft is connected to drive a first gear which is engaged to drive a second gear. The second gear is connected to rotate an output shaft extending through a strut away from the transmission shaft. A governor arrangement is configured to change a pitch angle of the blades in response to speed, and includes counterweights acting on a spring in the governor arrangement. The governor spring is positioned on an opposed side of the strut relative to the turbine.

Fan module for an aircraft turbine engine, the module including a fan having variable-pitch blades and an oil-transfer device configured to transfer oil between a stator and a rotor. The device includes a stator ring having internal oil ducts, a shaft engaged in the ring and having internal oil ducts, and a plain bearing and rolling bearings which are mounted between the ring and the shaft, the ring including first fluidic-connection ports which are configured to cooperate by male-female engagement with ends of oil-supply sockets during blind assembly of the device by axial translation downstream of the device as a whole.

There is provided a method and a system for detecting and mitigating a propeller failure condition. An actual value of a rotational speed of the propeller and/or of a pitch angle of blades of the propeller is obtained. In response to determining that the speed is below a reference rotational speed for the propeller and/or determining that the pitch angle is above a pitch angle threshold, an actuator operatively connected to the blades is commanded to decrease the pitch angle to increase the speed towards the reference speed. After commanding of the actuator to decrease the pitch angle, a subsequent value of the speed and/or a subsequent value of the pitch angle is obtained. The actuator is commanded to hold the pitch angle in response to determining that the speed has failed to increase towards the reference speed and/or determining that the pitch angle has failed to decrease.