Electrohydraulic pitch-control system with a valve pump in a rotating reference frame

A pitch change mechanism for a propeller, said pitch change mechanism comprising an electrohydraulic actuator comprising:

• a jack for actuating the propeller comprising a first chamber and a second chamber;
• a hydraulic pump adapted to selectively supply the first chamber or the second chamber with a pressurized hydraulic fluid;
• a hydraulic fluid tank configured to store the pressurized hydraulic fluid;
• and
• a valve configured to move between a first position, in which the valve puts the first chamber in fluid communication with the hydraulic pump, and a second position in which the valve puts the first chamber in fluid communication with the hydraulic fluid tank;
• wherein the hydraulic pump comprises a body, an inclined plate and a barrel, wherein the body of the hydraulic pump is in a rotating reference frame of a turbine engine, and one of the inclined plate and the barrel of the hydraulic pump is in a fixed reference frame of the turbine engine;
• wherein absent any rotation between the fixed reference frame and the rotating reference frame, a flow rate of the pump is null.

A pitch change mechanism for a propeller, said pitch change mechanism comprising an electrohydraulic actuator comprising:

• a jack for actuating the propeller comprising:
• a first chamber and a second chamber;
• a hydraulic pump adapted to selectively supply the first chamber or the second chamber with a pressurized hydraulic fluid;
• a hydraulic fluid tank configured to store the pressurized hydraulic fluid;
• a valve configured to move between a first position, in which the valve puts the first chamber in fluid communication with the hydraulic pump, and a second position in which the valve puts the first chamber in fluid communication with the hydraulic fluid tank;
• and
• a flow rate reversal valve configured to selectively put the hydraulic pump in fluid communication with the first chamber or the second chamber.