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.

Methods and systems for slowing down an aircraft having a propeller. The method comprises operating the propeller at a reference speed with the propeller blades in a first position, applying a load to the propeller to slow down a rotational speed of the propeller when the propeller is in a windmilling state or just before the propeller enters the windmilling state, adjusting the propeller blades to a second position in response to the load being applied, to increase the rotational speed of the propeller back towards the reference speed, and operating the propeller at the reference speed with the propeller blades in 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 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.

The variable pitch propeller control system can have a source of adjustable, actuation hydraulic pressure, a feather valve openable to provide an actuation path of the actuation hydraulic pressure between the source and the actuator, and closeable to connect the actuator to a drain below the actuation hydraulic pressure and close the actuator path, and a bypass path parallel to the actuator path, the bypass path having a restricted flow area relative to a flow area of the actuator path.

An electronic control system for a turbopropeller engine having a gas turbine and a propeller assembly coupled to the gas turbine is provided. The control system implements a propeller control unit to control propeller operation using an actuation assembly designed to adjust a pitch angle of propeller blades. The control unit engages a mechanical lock determining a minimum flight value for the pitch angle during a flight operating mode, and disengages the mechanical lock and controls the pitch angle below the minimum flight value, up to a minimum ground value lower than the minimum flight value, during a ground operating mode. The propeller control unit, during a transition from the ground operating mode to the flight operating mode, engages the mechanical lock. The control unit anticipates the increase of the pitch angle before the mechanical lock engagement when transitioning from the ground operating mode to the flight operating mode.

The present disclosure describes a propeller control unit for controlling the blade pitch of a propeller. The unit includes an electrohydraulic servo valve (“EHSV”) and is connected to a propeller actuator that adjusts the blade pitch of a propeller. The EHSV operates to allow pressurized fluid to flow from a pressurized fluid source to the actuator to adjust the blade pitch of the propeller in a flight pitch range and a ground pitch range, to allow pressurized fluid to flow from the source to the actuator to adjust the blade pitch of the propeller in a flight pitch range but not a ground pitch range, and to block the flow of pressurized fluid from the source to the actuator and drain pressurized fluid from the actuator to prevent adjustment of the blade pitch of the propeller in the flight pitch range or the ground pitch range.

The invention relates to a fan module having variable-pitch blades for a turbine engine, including a rotor (2) having blades (3), a stationary casing (7), and a system for adjusting and controlling the pitch of the blades (3), the rotor (2) including a central shaft (6) and a ring (9) for supporting the blades surrounding the shaft, a front end of the ring being connected to a front end of the shaft so as to define an annular space between the ring and the shaft which is open towards the rear, said annular space of the rotor (2) housing said system, and the shaft (6) being guided by a first bearing (8) mounted in the stationary casing (7), to the rear of the ring (9), characterised in that the ring (9) is guided by at least one complementary bearing (31) located upstream of the first bearing (8).

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.

A system for feathering a propeller assembly disposed within a housing of the propeller assembly has a sleeve defining an outer wall and one or more sleeve tabs extended outward in a radial direction along at least a circumferential portion of the sleeve, wherein the one or more sleeve tabs is separated from the outer wall in an axial direction, a retainer defining one or more retainer tabs extended inward in the radial direction, wherein the one or more retainer tabs is disposed between the outer wall and the one or more sleeve tabs of the sleeve along the axial direction, and a beta tube assembly extended through the sleeve along the axial direction. The beta tube assembly defines one or more internal walls. The one or more internal walls defines a hydraulic fluid transfer cavity in fluid communication with one or more hydraulic fluid transfer orifices.