BA 77,
Just to list what basic components most g'boxes have fitted to them and why:
- Fuel pump - often low and high pressure combined, draws fuel out of wing tanks
- Fuel controller - varies/controls the amount of high pressure fuel, based on throttle input/autothrottle inout, going to the fuel spray nozzles in the combustion chamber
- Oil pump assembly - providing pressure to supply all mainline bearings, and the g'box itself and scavenge/suction to recover oil afterwards
- Dedicated Generator/Permanent Magnet Alternator - provides electrical power to the engine systems - on a modern engine it's the FADEC (Full Authority Dedicated Engine Control system that needs this power - which includes the EEC/ECU - the 'brain' of the engine)
- IDG/CSD+Gen - Integrated Drive Generator or Constant Speed Drive and Generator assembly - providing main electrical power to the a/c systems
- Hydraulic Pump - supplying the main hydraulic pressure to the a/c systems for flight surface control, rudder, elevator, ailerons, landing gear retract etc
There are a number of other things on various g'boxes - oil pressure switches, speed indiactors, temp probes etc. But the above list is basically common to most large civilian a/c engines.
Brgd's
N1 Vibes