The present invention relates to a pitch-change mechanism for a turbine engine propeller, said turbine engine comprising a stator portion and a rotor portion, said pitch-change mechanism comprising an electrohydraulic actuator comprising: a cylinder for actuating the propeller, comprising a first chamber and a second chamber; a hydraulic pump suitable for selectively supplying the first chamber or the second chamber of the cylinder with pressurized hydraulic fluid; a hydraulic fluid reservoir configured to store a pressurized hydraulic fluid; a valve controlled between a first position in which the valve places the first chamber of the cylinder in fluid communication with the hydraulic pump, and a second position in which the valve places the first chamber of the cylinder in fluid communication with the hydraulic fluid reservoir.

The present invention relates to a pitch-change mechanism for a turbine engine propeller, said turbine engine comprising a stator portion and a rotor portion, said pitch-change mechanism comprising an electrohydraulic actuator comprising: a cylinder for actuating the propeller, comprising a first chamber and a second chamber; a hydraulic pump suitable for selectively supplying the first chamber or the second chamber of the cylinder with pressurized hydraulic fluid; a hydraulic fluid reservoir configured to store a pressurized hydraulic fluid; a valve controlled between a first position in which the valve places the first chamber of the cylinder in fluid communication with the hydraulic pump, and a second position in which the valve places the first chamber of the cylinder in fluid communication with the hydraulic fluid reservoir.

A gas turbine engine including: a turbomachine having 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 rotatable about the fan axis; and a pitch change mechanism operable with the plurality of fan blades, the pitch change mechanism including a plurality of linkages, the plurality of linkages including a first linkage coupled to a first fan blade of the plurality of fan blades and a second linkage coupled to a second fan blade of the plurality of fan blades; and a non-uniform blade actuator system operable with one or more of the plurality of linkages to control a pitch of the first fan blade relative to a pitch of the second fan blade.

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 rotatable about the fan axis; and a pitch change mechanism operable with the plurality of fan blades to control a pitch of the plurality of fan blades. The pitch change mechanism imparts a torque to each fan blade of the plurality of fan blades via first and second forces imparted in opposite directions to each fan blade of the plurality of fan blades.

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 hydraulic system for controlling orientation of fan blades in a turbine engine including at least one set of adjustable pitch fan blades actuated by actuators that are connected to a hydraulic pump, and a small pitch protection valve controlled by an associated solenoid valve to make it possible on the ground, when the orientation of the blades is substantially perpendicular to the axis of the turbine engine, to pass from a first operating zone in which a speed of pitch variation of the blades is low to a second operating zone in which a speed of pitch variation is considerably higher, wherein operating pressure of the hydraulic pump is controlled by the solenoid valve controlling the small pitch protection valve to define two outlet levels corresponding to the two operating zones.

A hydraulic system for controlling orientation of fan blades in a turbine engine including at least one set of adjustable pitch fan blades actuated by actuators that are connected to a hydraulic pump, and a small pitch protection valve controlled by an associated solenoid valve to make it possible on the ground, when the orientation of the blades is substantially perpendicular to the axis of the turbine engine, to pass from a first operating zone in which a speed of pitch variation of the blades is low to a second operating zone in which a speed of pitch variation is considerably higher, wherein operating pressure of the hydraulic pump is controlled by the solenoid valve controlling the small pitch protection valve to define two outlet levels corresponding to the two operating zones.

A central-positioned pitch control device used in a coaxial helicopter includes an upper propeller hub; a lower propeller hub; a first blade mounted on the outside of the upper propeller hub; a second blade mounted on the outside of the lower propeller hub; and a central-positioned pitch control device placed between the upper propeller hub and the lower propeller hub.

A propeller control unit for an aircraft propulsion system including a propeller is provided. The propeller control unit includes an actuator, a pump, a flow regulator, a pressure sensor, and a controller. The actuator is configured to control a pitch of each of the propeller blades. The pump is configured to direct hydraulic fluid to the actuator. The flow regulator is in fluid communication with the pump and configured to control a hydraulic fluid pressure of the hydraulic fluid downstream of the pump. The pressure sensor is disposed downstream of the pump and upstream of the actuator. The pressure sensor is configured to measure the hydraulic fluid pressure and generate a hydraulic fluid pressure signal. The controller includes a processor in communication with a non-transitory memory storing instructions, which instructions when executed by the processor, cause the processor to monitor the hydraulic fluid pressure signal.

A propeller control unit for an aircraft propulsion system including a propeller is provided. The propeller control unit includes an actuator, a pump, a flow regulator, a pressure sensor, and a controller. The actuator is configured to control a pitch of each of the propeller blades. The pump is configured to direct hydraulic fluid to the actuator. The flow regulator is in fluid communication with the pump and configured to control a hydraulic fluid pressure of the hydraulic fluid downstream of the pump. The pressure sensor is disposed downstream of the pump and upstream of the actuator. The pressure sensor is configured to measure the hydraulic fluid pressure and generate a hydraulic fluid pressure signal. The controller includes a processor in communication with a non-transitory memory storing instructions, which instructions when executed by the processor, cause the processor to monitor the hydraulic fluid pressure signal.