The invention relates to an auxiliary system for mechanically driving a relay shaft (8) of a helicopter propulsion system, comprising: a hydraulic motor (7), mechanically connected to said relay shaft (8); a hydraulic circuit (10) for supplying a pressurised liquid to said hydraulic motor(7) a controlled, fast-opening hydraulic valve (11) arranged on the hydraulic circuit (10); a pyro-hydraulic storage unit (9) driven by a control unit (12) and connected to said hydraulic valve (11), said pyro-hydraulic storage unit (9)comprising: an enclosure (20) including a piston (16) that defines a main compartment (17) having at least one solid propellant cartridge (19) and a compartment (18) for a liquid supply; an ignition charge (25) connected to said main compartment (17) and suitable for initiating the combustion of at least one solid propellant cartridge (19) upon receiving a command from said control unit (12).

A pyrotechnic device comprising a main pyrotechnic charge, a firing device for firing the main pyrotechnic charge, a discharge passage for discharging the gas generated by firing the main pyrotechnic charge, and an injector device configured to inject a cooling fluid into said gas discharge passage, so as to deliver gas, specifically for driving turbines, at temperatures that are relatively low, and a method of cooling gas generated by firing the main pyrotechnic charge by injecting the cooling fluid.

An emergency starter that allows responsiveness within a few seconds, without having disadvantages associated with mass and size of a back-up hydraulic or pneumatic starter. An instantaneous gas thrust of pyrotechnic type is coupled with a positive displacement transmission generator in conjunction with automatic coupling to/uncoupling from a set that is to be started. An emergency start-up system includes at least one pyrotechnic gas generator connected to an electrical initiator itself connected to a computer, a positive displacement motor housing straight-cut gears, the pyrotechnic gas generator being coupled to the motor by an inlet in the casing. The motor includes a mechanism of connection capable of moving at one end of the drive shaft configured to couple the transmission shaft to a driven shaft of the set that is to be started via a centrifugal clutch.

An emergency starter that allows responsiveness within a few seconds, without having disadvantages associated with mass and size of a back-up hydraulic or pneumatic starter. An instantaneous gas thrust of pyrotechnic type is coupled with a positive displacement transmission generator in conjunction with automatic coupling to/uncoupling from a set that is to be started. An emergency start-up system includes at least one pyrotechnic gas generator connected to an electrical initiator itself connected to a computer, a positive displacement motor housing straight-cut gears, the pyrotechnic gas generator being coupled to the motor by an inlet in the casing. The motor includes a mechanism of connection capable of moving at one end of the drive shaft configured to couple the transmission shaft to a driven shaft of the set that is to be started via a centrifugal clutch.

An emergency start system for a turbine engine of an aircraft including at least one solid propellant gas generator, an electrically controlled ignition device, a computer connected to the ignition device, and at least one starter motor comprising a turbine for driving a shaft which is for coupling to a shaft of the turbine engine The outlet of the gases from the generator are connected to the inlet of the turbine of the starter motor.

An emergency start system for a turbine engine of an aircraft including at least one solid propellant gas generator, an electrically controlled ignition device, a computer connected to the ignition device, and at least one starter motor comprising a turbine for driving a shaft which is for coupling to a shaft of the turbine engine The outlet of the gases from the generator are connected to the inlet of the turbine of the starter motor.

The invention relates to a system for emergency starting a turbine engine, characterised in that it comprises a flyer for driving the turbine engine, said flyer comprising a drum (2) rigidly connected to a rotary shaft (3), the axes of symmetry (LL) of the drum (2) and of the shaft being coincident, the flyer further comprising at least one exhaust nozzle (4) for ejecting gas, which is positioned on the periphery of the drum (2) and oriented substantially tangentially to the rotation about said axis (LL), and a pyrotechnic gas generation device which is installed in the flyer and feeds said at least one exhaust nozzle (4), said emergency start system further comprising a support in which the shaft of the flyer rotates, and a volute for recovering the gases, which radially surrounds the flyer and is rigidly connected to said support.

The invention relates to a system for emergency starting a turbine engine, characterised in that it comprises a flyer for driving the turbine engine, said flyer comprising a drum (2) rigidly connected to a rotary shaft (3), the axes of symmetry (LL) of the drum (2) and of the shaft being coincident, the flyer further comprising at least one exhaust nozzle (4) for ejecting gas, which is positioned on the periphery of the drum (2) and oriented substantially tangentially to the rotation about said axis (LL), and a pyrotechnic gas generation device which is installed in the flyer and feeds said at least one exhaust nozzle (4), said emergency start system further comprising a support in which the shaft of the flyer rotates, and a volute for recovering the gases, which radially surrounds the flyer and is rigidly connected to said support.

The invention relates to a drive chain for driving the rotor(s) (21, 22) of a helicopter, comprising a main transmission gearbox (24) capable of driving the rotor(s) (21, 22) when said gearbox is moving, a main engine (23) for providing the power for the flight, and at least one assistance drive module (31), the main engine (23) and the assistance drive module (31) being mechanically connected to said main transmission gearbox (24) so as to induce the movement of said gearbox. The drive chain is characterised in that the assistance drive module comprises a pyrotechnic device for generating a torque on a power transmission shaft that is mechanically connected to the main transmission gearbox (24). The invention also relates to a helicopter comprising said drive chain.

The invention relates to a drive chain for driving the rotor(s) (21, 22) of a helicopter, comprising a main transmission gearbox (24) capable of driving the rotor(s) (21, 22) when said gearbox is moving, a main engine (23) for providing the power for the flight, and at least one assistance drive module (31), the main engine (23) and the assistance drive module (31) being mechanically connected to said main transmission gearbox (24) so as to induce the movement of said gearbox. The drive chain is characterised in that the assistance drive module comprises a pyrotechnic device for generating a torque on a power transmission shaft that is mechanically connected to the main transmission gearbox (24). The invention also relates to a helicopter comprising said drive chain.