Pressure-balance valve for balancing fluid feed to actuator cylinders of a servo-control for controlling rotor blades of a rotorcraft

A pressure-balance valve for balancing the pressures of different fluids flowing respectively in a plurality of double-acting actuator cylinders of at least one servo-control suitable for driving a member for varying flight attitude of an aircraft, the valve including a valve cylinder comprising at least:

• a chamber for guiding a piston to move in translation along an axial extension direction of the chamber;
• two first ducts opening out into the chamber and each serving to convey a flow of a respective fluid between the outside and the inside of the valve;
• two passages for individually conveying the fluids into the inside of the valve respectively between the first ducts and the second ducts, each opening into the chamber and serving to convey a flow of a respective fluid between the outside and the inside of the valve;
• and
• at least one bleed duct for the draining fluids admitted into the inside of the chamber;
• each fluid flow path of the pressure-balance valve for conveying a respective fluid including distinctly at least a first duct, a said passage, and a second duct placed mutually in fluid flow communication;
• wherein for each of the fluid flow paths, the first duct is provided at its outlet to the chamber with a movable shutter that co-operates with a ramp formed on the piston, sliding of the shutter along the ramp caused under the effect of the piston moving in translation inside the chamber disengaging the outlet of the first duct and consequently placing the first and second ducts in fluid flow communication with each other via the passage, the first duct and the second duct in fluid flow communication with each other delivering additional fluid through the passage from the first duct to the second duct.