The pressurized oil reaches the pistons in the piston housing through servo-valves. Grouped together on a support known as the brake manifold, the servo-valves distribute and control the flow of oil towards each piston housing. A servo-valve allows adjusting the pressure of the oil flow to a certain degree of precision. The BSCU (braking and steering control unit) therefore controls the servo-valve of each brake, opening it to a greater or lesser extent, depending on the force transmitted by the pilot’s pedal, and controlling the oil pressure that reaches the brakes. The opening of the servo-valves is adjusted constantly by the BSCU, which compares the speed of the aircraft with the speed of the wheels.
In new-generation electric brakes, these servo-valves are replaced by an electrical system, and hydraulic energy is no longer needed.
