US 11,852,023 B2
Method for quickly stopping the rotor of a helicopter after landing
Olivier Bedrine, Moissy-Cramayel (FR); Jean Michel Frédéric Louis Bazet, Moissy-Cramayel (FR); and David Cazaux, Moissy-Cramayel (FR)
Assigned to SAFRAN HELICOPTER ENGINES, Bordes (FR)
Appl. No. 17/754,885
Filed by SAFRAN HELICOPTER ENGINES, Bordes (FR)
PCT Filed Oct. 14, 2020, PCT No. PCT/FR2020/051826
§ 371(c)(1), (2) Date Apr. 14, 2022,
PCT Pub. No. WO2021/074531, PCT Pub. Date Apr. 22, 2021.
Claims priority of application No. 1911630 (FR), filed on Oct. 17, 2019.
Prior Publication US 2023/0193779 A1, Jun. 22, 2023
Int. Cl. F01D 21/12 (2006.01); F02C 7/25 (2006.01)
CPC F01D 21/12 (2013.01) [F02C 7/25 (2013.01); F05D 2220/329 (2013.01); F05D 2270/09 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for quickly stopping a main rotor of a helicopter after landing, the helicopter comprising:
the main rotor for propulsion of the helicopter;
at least one turbomachine;
a main gearbox connected between said at least one turbomachine and the main rotor;
a turbomachine control unit;
an electric power supply network; and
at least one electrical machine coupled to the electrical power supply network, said at least one turbomachine including:
a gas generator equipped with a mechanical shaft;
a free turbine coupled to the main rotor via the main gearbox and mechanically independent of the mechanical shaft of the gas generator; and
a system configured to mechanically couple the at least one electrical machine to the gas generator,
wherein the method comprises, following a step of requesting a quick stop of the at least one turbomachine by a helicopter pilot, causing an extinction of a combustion chamber of the gas generator of the at least one turbomachine, the following steps managed by the turbomachine control unit of the at least one turbomachine:
detecting an absence of a thermal stabilization phase of the gas generator of the at least one turbomachine to confirm that the step of requesting the quick stop of the at least one turbomachine is a request for quickly stopping the main rotor,
in the event of absence of the thermal stabilization phase, maintaining the rotation of the gas generator of which the combustion chamber is extinguished, by means of said at least one electrical machine mechanically coupled to the gas generator and powered by the electrical power supply network, to ventilate the gas generator, and
stopping the main rotor of the helicopter by means of a brake.