Thinking in a black box style,can be a provocative,stimulative and short manner to dream up about the unknown.
   This time,in the line with the topic,the black box is supposed to 'hide"  inside, a "wheel" ,or something like this.
   We know the input and the output of the black box.
   The input is the gravity,the output is hoped for a working torque.
   How  about the "wheel"?
   Here,it's  a full place for fancy,guess,suppositions...as this place and topic is intended to be.
   My opinion ,is to think big about this  "wheel".
   My  first suggestion is to imagine it,as a big-size radius mechanism,machine(as a Ferris Wheel,or better as that buildt by Aldo Costa).
   My  second suggestion is to make a big "cut" in the design:we need two spokes ,only.
   The next step is a big change in the concept:we  are  dealing not with a wheel,but with a lever(if you like more a wheel image,you can call,name this lever as a  "minimal" wheel).
   One more step,is to add,couple this one with a mechanically store-restore power system(let's say a flywheel,a pulsatory flywheel).
   The  last but one proposition, is to bring about the self switching long arm-short arm  configuration,on the same side of the fulcrum/pivot ,with the help of an incline .
   And finally,the last invitation is to leave you, unaccompanied to think about.
   So,if I completed my description in some words,I hope you can understand it,someway.
                               All  the Bests! / Alex

.....let's say , as : http://alphaplanets.com
     Al_ex

They claim over 3000% efficiency
They state the device is up to 97% efficient


Which is it?

edit.