A system and method for feathering an aircraft propeller are provided. The aircraft propeller is coupled to an actuator for setting a blade pitch of the propeller. The blade pitch is controlled by modulating a supply of hydraulic fluid to the actuator. At least one feather solenoid is provided that comprises a first solenoid coil, a second solenoid coil, and a solenoid valve coupled to the actuator and to the first and the second solenoid coil. At least one controller is configured to selectively energize and de-energize the first and the second solenoid coil. The solenoid valve is configured to be activated when the first solenoid coil and the second solenoid coil are de-energized and to, when activated, modulate the supply of hydraulic fluid to the actuator for adjusting the blade pitch of the propeller towards a feather position.

The invention relates to a fan module with variable-pitch blades for a turbomachine, comprising a rotor (2) carrying blades (3), a stationary housing (7), a mechanism (11, 12, 13, 14, 20) for regulating the pitch of the blades (3), which is connected to the rotor, and a control means (16, 17) mounted on the stationary housing (7) and comprising a control part (18) that can be moved in translation according to an axis (X) of rotation of the rotor (2), and a bearing (19) for load transfer between the control part (18) and said mechanism, characterised in that it also comprises a stationary track (23) supporting the elastic restoring means (26, 27) which are arranged so as to exert an axial restoring force on the control part (18) towards a determined position, preferably corresponding to the blade (3) feathering.

A method for controlling an aircraft propeller is provided that comprises obtaining a measurement of a speed of the propeller, comparing the propeller speed to a first threshold, responsive to determining that the propeller speed exceeds the speed threshold, outputting a valve control signal for opening a two-position solenoid valve coupled to the propeller, the two-position solenoid valve configured for controlling fluid flow to and from the propeller to control propeller blade angle, computing a rate of change of the propeller speed, comparing the rate of change of the propeller speed to a second threshold, and responsive to determining that the rate of change of the propeller speed is below the second threshold, outputting the valve control signal for closing the two-position solenoid valve. A system for controlling an aircraft propeller and an aircraft propeller control assembly are also provided.

A propeller pitch control system for a turboprop engine of an aircraft includes a negative torque sensor, a full feather control valve assembly, and a feather valve assembly. The feather valve assembly is responsive to fluid pressures from the negative torque sensor and the control valve assembly to move between a plurality of positions. An engine control unit or a manual user interface can also be used to control the position of the feather.

A control circuit for changing the angle of propeller blades includes a propeller pitch change mechanism, and a fixed-displacement pump providing the supply of oil from an engine oil return system. A valve has an outlet port to direct oil from a cavity of the valve, and a pitch port in fluid communication with the pitch change mechanism. A spool of the valve is operable between a first position and a second position to respectively open and close the outlet port, and direct oil flow away from or to the pitch change mechanism.

A variable pitch propeller assembly operatively coupled with an engine and methods for controlling the pitch of a plurality of propeller blades thereof is provided. In one example aspect, the variable pitch propeller assembly includes features for combining overspeed, feathering, and reverse functionality in a single secondary control valve. The secondary control valve is operable to selectively allow a controlled amount of hydraulic fluid to flow to or from a pitch actuation assembly such that the pitch of the propeller blades can be adjusted to operate the variable pitch propeller assembly in one of a constant speed mode, a feather mode, and a reverse mode.

Methods and systems for governing an aircraft propeller of an engine are described. The method comprises obtaining a fluid flow command for speed control of the propeller, determining pulse parameters of a pulse width modulated valve control signal for actuating a two-position solenoid valve in accordance with the fluid flow command based on an average fluid flow through the solenoid valve and an opening and closing time of the solenoid valve, generating the valve control signal with the pulse parameters as determined, and transmitting the valve control signal to the solenoid valve for actuating the solenoid valve, thereby controlling the speed of the propeller.

A propeller pitch control system for a turboprop engine of an aircraft includes a negative torque sensor, a full feather control valve assembly, and a feather valve assembly. The feather valve assembly is responsive to fluid pressures from the negative torque sensor and the control valve assembly to move between a plurality of positions. An engine control unit or a manual user interface can also be used to control the position of the feather.

The present disclosure is directed to a turbine engine (10) defining an axial direction, a radial direction, a circumferential direction, a first end (99) and a second end (98) opposite of the first end (99) along the axial direction. The turbine engine includes a propeller assembly (14) proximate to the first end including a plurality of blades (42) arranged in the circumferential direction disposed around an axial centerline (12), and a feathering mechanism (60) including a hollow piston rod (19). The feathering mechanism rotates the plurality of blades about a pitch axis (13) extended in the radial direction from the axial centerline. The turbine engine further includes a housing (45) proximate to the second end disposed in adjacent arrangement with the propeller assembly in the axial direction. The axial centerline is defined through the propeller assembly and the housing. The turbine engine further includes a beta tube assembly (100) extended through the hollow piston rod and at least partially through the housing in coaxial alignment with the axial centerline. The beta tube assembly defines an at least partially hollow walled pipe (101) extended along the axial direction. The beta tube assembly further defines a plurality of grooves (111, 112) extended along the axial direction proximate to the housing. A first groove (111) extends at least partially in the circumferential direction and along the axial direction to at least partially define a helix (114) corresponding to a rotatable range of the plurality of blades about the pitch axis, and a second groove (112) extends in the axial direction.

An actuator is disclosed comprising: a moveable member; a first hydraulic chamber in contact with a first surface of the moveable member; a second hydraulic chamber in contact with a second, opposing surface of the moveable member; a movable locking mechanism coupled to a moveable wall of the second hydraulic chamber; and a resilient biasing member acting on the moveable wall of the second hydraulic chamber so as to bias the moveable wall and locking mechanism. The actuator is configured to selectively vary the pressure in the second hydraulic chamber so that the resilient biasing member is able to bias the moveable wall to move, thereby moving the locking mechanism to engage the moveable member so as to prevent the movement of the moveable member towards at least one of the first and second hydraulic chambers.