4 ms·
The engine core (hot part) works best at a different speed than the fan part - fast and hot, vs slow and cool. hence they have a gearbox. But it's not like a ca
by spitfire 13y ago
The engine core (hot part) works best at a different speed than the fan part - fast and hot, vs slow and cool. hence they have a gearbox. But it's not like a cars gearbox, it has a single gear.
- hollerith 13y agoNo, they don't have a gearbox (yet). What the current generation of engines have is two or three co-axial shafts rotating at different speeds. The difference in shaft speeds is achieved by varying the size, shape and placement of the turbine blades connected to the shaft, not with a gearbox. (And a single gear in isolation would be pointless. By definition, the purpose of a gear is to mesh with another gear.) Here's an informative video: http://www.youtube.com/watch?v=zy4A-z2WKhw http://www.youtube.com/watch?v=zy4A-z2WKhw
- TheLegace 13y agoI think the counter-spin turbine is really innovative idea. I wonder if it makes a big deal in terms of efficiency. http://youtu.be/zy4A-z2WKhw?t=7m3s http://youtu.be/zy4A-z2WKhw?t=7m3s
- johntb86 13y agoAren't we talking about geared turbofans, as described in the article and http://en.wikipedia.org/wiki/Geared_turbofan http://en.wikipedia.org/wiki/Geared_turbofan ? Geared turbofans, unlike the ungeared GEnx, presumably have gears in gearboxes.
- hollerith 13y agoThe person I replied to implied that all turbofan engines have gearboxes, that gearing was necessary to have the fan rotate at a slower speed than the "main engine". In reality, the vast majority of the turbofan engines currently used in commercial aviation do not have gearboxes. The engines referred to in the wikipedia article you cite are still in development or just entering production.