Traction drive transmission research
Traction, friction., they both involve extreme pressure whether it be pressure on rollers or in the case of traction I assume pressure on fluid retaining seals. The Masquito boys in Belgium tried a hydraulic tail rotor drive gearbox but changed it to a cable drive because if I remember correctly they either could not get it to hold oil for long enough , or maybe the whole thing got too hot. Getting too hot is not an uncommon problem when using a viscous medium to transmit power especially when attempting to gear up. As this is being looked at regarding its possible use in very light rotorcraft, one has always to bear in mind that the CAA and I assume FAA, like to see components that have some track record, and so any innovative ideas might not sit well with them.The Masquito M80 also had originally a 12 foot dia main rotor. I was present with them during discussions where they were trying to explain how the autorotational quality was up to the required standard, but for the life of me I could not understand how given the high disc loading, they achieved this. Development of the M80 is I believe on hold for the moment, which is a great pity as these chaps had really given it their all.