A blade pitch actuation mechanism comprising a rotating race member in which is formed a race configured to receive a trunnion pin attached to a blade, whereby the race defines a cam profile such that rotation of the race member causes the trunnion pin received in the race to rotate as it slides over the cam profile.

An engine control device having a calculator for calculating a pitch setpoint for at least one propeller of the engine, the calculator taking account at least of a flight speed.

An engine control device having a calculator for calculating a pitch setpoint for at least one propeller of the engine, the calculator taking account at least of a flight speed.

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.

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 blade pitch control assembly includes a pitch control actuator having a coarse actuator chamber having a coarse chamber area and a fine actuator chamber having a fine chamber area. The coarse chamber area is biased to a feather position. The assembly also includes a primary pitch control valve configured to control the flow of pressurised fluid to the coarse actuator chamber and the fine actuator chamber, respectively via a coarse fluid line and a fine fluid line. The assembly further includes a hydraulic protection system located between the actuator and the primary pitch control valve, configured to bypass the primary pitch actuator in response to a trigger. The hydraulic protection system has a hydraulic protection system valve located between the fluid lines and when activated fluidly connects the fluid lines to balance fluid pressure between the coarse chamber and the fine chamber.

A blade pitch control assembly includes a pitch control actuator having a coarse actuator chamber having a coarse chamber area and a fine actuator chamber having a fine chamber area. The coarse chamber area is biased to a feather position. The assembly also includes a primary pitch control valve configured to control the flow of pressurised fluid to the coarse actuator chamber and the fine actuator chamber, respectively via a coarse fluid line and a fine fluid line. The assembly further includes a hydraulic protection system located between the actuator and the primary pitch control valve, configured to bypass the primary pitch actuator in response to a trigger. The hydraulic protection system has a hydraulic protection system valve located between the fluid lines and when activated fluidly connects the fluid lines to balance fluid pressure between the coarse chamber and the fine chamber.

A turbine engine including: a rotor supporting a blade and guided by means of bearings; a control system for controlling the blade, which is solidly connected to the rotor and which includes an actuator driven by energy, the control system being disposed axially upstream of the bearings; and a device for transferring the energy, disposed axially between the bearings and including a stationary member and a moving member. The rotor includes a support ring supporting the blade and a shaft having a frustoconical portion and a cylindrical portion on which the bearings and the moving member are mounted, the frustoconical portion extending about the cylindrical portion.

A turbine engine including: a rotor supporting a blade and guided by means of bearings; a control system for controlling the blade, which is solidly connected to the rotor and which includes an actuator driven by energy, the control system being disposed axially upstream of the bearings; and a device for transferring the energy, disposed axially between the bearings and including a stationary member and a moving member. The rotor includes a support ring supporting the blade and a shaft having a frustoconical portion and a cylindrical portion on which the bearings and the moving member are mounted, the frustoconical portion extending about the cylindrical portion.

A rotor blade pitch control system (15) comprising a rotor blade (19a, 19b, 19c, 19d) rotatable about both a central axis (20) and a pitch axis (24a, 24b, 24c, 24d), a pitch drive rotor (32a, 32b, 32c, 32d) rotatable about the central axis independently of rotation of the rotor blade about the central axis, a pitch follower (40a, 40b, 40c, 40d) rotatable relative to the pitch drive rotor, the pitch drive rotor and the pitch follower having an eccentric axis (33a, 33b, 33c, 33d), a linkage (50a, 50b, 50c, 50d) between the pitch follower and the rotor blade configured such that the pitch follower rotates with rotation of the rotor blade about the central axis, the pitch drive rotor, the pitch follower and the linkage configured such that the pitch drive rotor may be driven to control an angular displacement of the pitch drive rotor relative to the pitch follower about the central axis and thereby control the pitch of the rotor blade about the pitch axis.