METHOD AND SYSTEM FOR THE EMERGENCY START-UP OF AN ENERGY GENERATOR SET

• US 20150128592A1
• Filed: 04/18/2013
• Published: 05/14/2015
• Est. Priority Date: 04/27/2012
• Status: Active Grant

• Current Assignee: Safran Helicopter Engines
• Original Assignee: Turbomeca
• Inventors: Filiputti, Hugues, Thiriet, Romain, Garde, Franck
• Granted Patent: US 10,072,580 B2
• Time in Patent Office: Days
• US Class Current: 60/632
• CPC Class Codes: F02C 7/26 Starting; Ignition
• CPC Class Codes: F02C 7/272 generated by cartridges
• CPC Class Codes: F02C 7/275 Mechanical drives
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

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.

Claims

1-13. -13. (canceled)

14. An emergency start-up method for an energy generator set, comprising:

if an emergency start-up situation for the set is detected, triggering at least one pyrotechnic gas combustion generator;

generating pressurized gases by combustion and gases injected directly into a positive displacement motor with gear wheels, a portion of the gases rotating gear wheels of a motor and, simultaneously, remaining portion of the gases projecting a coupling connection between the motor and the set, against a restoring force, the coupling connection bringing about transmission of energy by rotating a gear shaft of the positive displacement motor on a driven shaft of the set; and

when thrust falls below the restoring force, the restoring force automatically repels the coupling connection and the set is disconnected from the positive displacement motor.

15. An emergency start-up method according to claim 14, wherein the coupling connection between the gear shaft and the driven shaft of the set to be restarted is produced by friction.

16. An emergency start-up method according to claim 14, wherein the remaining gases are injected into the positive displacement motor peripherally about a longitudinal axis so that the coupling connection uses radial compression to rotate the shaft of the set to be restarted.

17. An emergency start-up method according to claim 15, wherein the remaining gases are injected into the positive displacement motor centrally along a longitudinal axis so that the coupling connection uses conical coupling to rotate the shaft of the set to be restarted.

18. An emergency start-up method according to claim 14, wherein successive instances of pyrotechnic gas combustion generation are triggered.

19. An emergency start-up method according to claim 15, wherein the restoring force is generated by one of elastic force, electromagnetic force, or expansion of a compressed fluid.

20. An emergency start-up system for an energy generator set configured to implement the method according to claim 14, comprising:

at least a pyrotechnic gas generator connected to an electrical initiator, itself connected to a computer;

a positive displacement motor comprising a casing defining an internal space housing gear wheels, or straight-cut, the pyrotechnic gas generator being coupled to the motor by an inlet in the casing;

wherein the motor includes connection means, configured to move at one end of a drive shaft centred about a gear-wheel axis of the positive displacement motor, configured to couple the drive shaft to a driven shaft of the set via a centrifugal clutch; and

wherein a return means arranged in abutment is configured to exert a restoring force against pressure exerted on the connection means.

21. An emergency start-up system according to claim 20, wherein an annular space, formed in an extension of the casing on a periphery of the drive shaft of the positive displacement motor, communicates with the internal space to allow some of the gases coming from the combustion of the pyrotechnic gas to be injected as far as the connection means, the connection means including an annular piston, configured to be moved in translation by thrust of the gases along the drive shaft of the motor, to exert pressure on a ferrule configured to move aside radially under pressure and driving the centrifugal clutch by friction.

22. An emergency start-up system according to claim 21, wherein the ferrule includes at least an open annular portion, which is moved aside radially by sliding along a conical portion of the drive shaft of the motor.

23. An emergency start-up system according to claim 21, wherein a conduit connected to the gas inlet of the casing communicates with a central bore of the drive shaft to allow some of the gases coming from the pyrotechnic gas generator to circulate as far as the connection means, the connection means including a conical piston, configured to be moved in translation by thrust of the gases along the axis of the drive shaft of the motor, to become housed in a tapered bore, rigidly connected to the centrifugal clutch, to drive it by friction.

24. An emergency start-up system according to claim 21, wherein the electrical initiator includes an electronic unit including an autonomous electrical power source, and an electronic control board incorporating a heat-sensitive component and a microcontroller for managing the electrical power source, the heat-sensitive component, functional self-tests and alarms for triggering an ignition cartridge of the pyrotechnic gas generator.

25. An emergency start-up system according to claim 21, wherein the gear wheels of the positive displacement motor are spur pinions.

26. An emergency start-up system according to claim 21, wherein the set is a turbine engine including a shaft of an HP spool, and the driven shaft is chosen from a shaft of an accessory gearbox mounted on the HP spool, a bell housing rigidly connected to a pinion of the accessory gearbox and used as a centrifugal clutch, or the shaft of the HP spool.