Brake system for aircraft undercarriage

A braking system for an aircraft (2) provided with an undercarriage (7) including a wheel (10), comprising:

• an axial-flux reversible electrical machine (20) associated with at least one wheel of the undercarriage and set in rotation by the rotation of the wheel, the electrical machine having at least one rotor (32a, 32b, 32c) and at least one stator (34a, 34b) with windings (36a, 36b, 36c);
• current-dissipator means (40a, 40b, 40c) to the windings (36a, 36b, 36c) of the axial-flux reversible electrical machine (20) during rotation of the wheel (10) in a landing phase for dissipating in the current-dissipator means (40a, 40b, 40c) the induced currents generated by the electrical machine (20), functioning as a current generator (20), and producing a braking effect that slows down the movement of the wheel (10);
• an epicyclic reducer (21) set between the wheel (10) of the undercarriage and the at least one rotor (32a, 32b, 32c) of said reversible electrical machine (20);
• an accumulation device (46) connectable to the axial-flux reversible electrical machine (20) for storing the electrical charge not dissipated in the current-dissipator means (40a, 40b, 40c);
• and
• control means (50) for governing the transfer of electrical charge from the accumulation device (46) to the axial-flux reversible electrical machine (20) for supplying further power for braking;
• the control means (50) also governing the transfer of electrical charge from the accumulation device (46) when the velocity of rotation of the wheel drops below a first threshold value;
• the control means (50) further governing the transfer of electrical energy from an electrical network (55) of the aircraft to the reversible electrical machine when the velocity of rotation of the wheel drops below a second threshold value lower than the first threshold value;
• the epicyclic reducer (21) providing a transmission ratio T in such a way that the at least one rotor (32a, 32b, 32c) will turn at a velocity Tω with respect to the velocity of rotation ω of the wheel (10).