"Huge" is a nice adjective A-G, but not actually a quantifiably accurate assessment..autogyro wrote:Lay shaft gearboxes running in so called 'direct top' gear still have the complete gear train rotating in oil.autogyro wrote:Layshaft (vs 'indirect') gearbox design offers a 1-1/direct top gear ratio with less loss of transmission 'efficiency'..
Perhaps a compact/annular mounting epicylic-type gearing set-up - is what you are angling for A-G?
Even in top gear they can be compared directly with a washing machine.
The torque loss is huge, try turning one by hand.
As to figures for efficiency, the losses from oil drag is conveniently ignored in most cases and always has been.
It is possible to produce a stepped ratio gear box with no engaged gear movement at all and only one shaft bearing in direct top gear.
An eight speed version goes into an 84 mm box with no need for a clutch.
Racing motorcycles from ages past - have utilized low-loss transmissions, & small mills cant afford much loss..
.. inc' not requiring heavy oil/sumps for racing purposes..
Manolis has some interesting transmission ideas, apparently efficient enough for use in human powered vehicles..