Another geared turbofan
 

Looks like Pratt will not be alone in building a geared turbofan engine. RR and Liebherr have decided to jointly develop one. I wonder if GE will follow suit. They've long been opposed to geared jet engines.

ROLLS-ROYCE and LIEBHERR-AEROSPACE agreed to form joint venture to develop power gearbox for new UltraFan engine; initial power gear drive components will be manufactured by Liebherr.

Technology marches on, just like fan vs pure jet, composite fans vs all metal.

The carrot is in the niche market that supports such technology jumps. This is where to watch.

Gears are complicated, fallible lumps of suspect metal, with thousands of stress points.... anyone considered using a solid bit of kit to change speed??
Nip back to your textbooks and look at the Eddy Current Dynamometer...
Or if that doesn't grab your intellect, put an alternator (solid) in the same axis as a motor and multiply/divide frequency electronically.
Can't visualise it??? Should be coming to a hybrid vehicle near you soon....

Diesel electric subs have been around for years.

Not exactly cutting edge stuff - the Honeywell TFE 731s are exceptionally reliable And fitted to plenty of aircraft.

A gear ratio of 0.556 between the Fan and the N1 shaft. Surely scaling up the size isn't that complicated? I admit it's a fairly low bypass (3.1) to the kind of massive engines powering the big boys, but does that make a huge difference?

Quote: "Gears are complicated, fallible lumps of suspect metal, with thousands of stress points..."

Strange then that every gas turbine has a gear box and an oil pump, all full of gears! :hmm:

Anyway, R-R were looking at geared turbofans yonks ago, it's nothing new. ;)