Lonewolf 50,
.... it seems that more than trivial savings will come due to needing fewer reduction gears, and thus a smaller and lighter transmission.
Yes, the coaxial arraignment of; motor, reducer and rotor allows for the use of a planetary gearbox and this has the best power-to-weight of any reducer.
In addition, the motor can have electrical reduction and this can eliminate the mechanical gear box altogether.
onetrack,
Since the discovery and use of high power magnets there are now Permanent Magnet Motors that have very high power-to-weight ratios. In addition, the motor can be significantly overpowered for a short period of time, as long as the heat does not get too high and start demagnetizing the magnets.
Power storage is definitely the problem at present, but a lot of R&D money is looking into it.
arismount,
The hybrid sound like a good near-term solution and perhaps long-term solution for rotorcraft. Eurocopter has a video on the net, which might have been linked to on a previous PPRuNe thread. It shows a full size mockup of a hybrid helicopter. When asked about the timeline, the person being interview smiled and say that maybe in 10 years......
The above sounds like a sales pitch for electric helicopters, but we all seem to agree that electric drives and controls may eventually provide meaningful improvements.
Dave