Originally Posted by CEFOSKEY
It would be a shaft brake, but not necessarily a rotor brake, as I am sure there is a sprag-clutch-type device buried somewhere in there.
There could be one, but the worm gear is also what coordinates both rotors there. If at some point they would rotate freely from the worm gear - the helicopter would beat itself to death with it's own rotor blades... the ground tests would be fun to watch
Dave, it's been a while since I was into worm gears, but one allowing the worm gear to be driven by the wheel gear, with the same efficiency as the other way around would be, well... revolutionary. Worm gears are great when the power have to be transfered in one direction, they allow very high ratios with compact and cheap design, but it all comes at a price.
The transmission design like on the Flettner drawing, look unsafe, and probably less efficient than a hydraulic drive would be, and you can do a lot with those... although with the price of efficiency too. I wouldn't be too attached to the design details from the pioneers times... after all , we all know how this one ended:
Ok, back to X2.