The toroidal type CVT itself is a miniaturized version of CVT's used
in some small cars. The final belt drive isolates the CVT from the
torque variations of the rotary engine. Clamping force is applied to the
CVT toroids by engine oil pressure. This is achieved by a annular
hydraulic cylinder throw out type bearing/clutch cylinder combination
now widely used on manual transmission cars. I invented this around
1971. I did not patent it but it was first sold by the new
owners of Lamar Engineering for race car use.

Looks good Paul,
I like the CVT, this always struck me as an ingenius way to change
gear ratios. The only question I have is to the exterior toroid and "intermediate
toroid" materials. Wear on these parts will be critical to the success of the
transmission. The Subaru Justy used a steel v-belt and sheeve I believe.
The wear on the transmission parts was a sore point. I still like the idea
though. I think you could even simplify the CVT ratio change using a bob
weight like the snowmobiles. The servo motor with a simple control
program will probably be more efficient. Looks like a fun project, count
me in if you need help.
Bill Jepson

The trick is to use hard steel on hard steel. Here are my back of the envelope 
calculations. 17 foot pounds max input.  17 foot pounds = 204 inch pounds.... 66 pounds 
shear for one wheel at the 3 inch radius. 132 pounds for one wheel at 1.5 
inch radius. 265 pounds shear for one wheel on a .75 radius.  Numbers are
half this for two wheels.

Coef. of friction for hard steel on hard steel = .78 (Marks SHFME) 

That implies 338 pounds clamping force needed for one wheel. 265/.78. 

At 90 PSI engine oil pressure... 5.5 inch dia. piston with 23 square 
inches gives  2000 pounds maximum clamping force available. Less when
not needed as engine RPM and HP goes down.... so too the oil pressure. 
It will work! The gear case will be robust. 

Paul Lamar
 
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