Jet engine gearbox question

[BA 77]

Hi all,

Do any of the engineers out there know if jet engine gearbox gears are hollow or solid? From a weight point of view I'd have thought it would be hollow but I don't know how you would actually manufacture that.

I know it's a bit of a strange question but I've always wondered and google hasn't been my friend this time.

Thanks in advance,
BA 77

[mat777]

do you mean as in the generator CVG's hung off the bottom of the engine?

[Papa2Charlie]

They're solid gears. Normally from steel with a silver coating on the mating teeth. The casing are made from cast aluminium or magnesium depending on the type of engine.

[BA 77]

Thanks for the replies. Is that the casing around the whole gearbox that's made of Aluminum/Magnesium, or on the gears themselves?

[Papa2Charlie]

Hi BA,

It's the casing around the gearbox that's made from Al or Mg. Older ones tend to have Mg gearboxes (e.g. RB211-535E4)

Cheers,

P2C