Hi Paul,

What do you think about a traction drive being used as as a PSRU? The
Nasvytrac drive has been with us for decades, originally designed as a
helicopter turbojet to main rotor powertrain component
(http://www.nastecinc.com/traction.htm).

Lately, some of the diagrams that have been shown on the Rotary Engine
group look like they may be able to offer a low cost alternative to
planetary gears. Sometimes, the PSRU costs about as much as the engine
itself.

Thank you,

Dale Mahan

That is interesting. Doug thinks Rotrex stumbled on the principle.

Traction drives go way back. McCullock back in the late 30's built
a supercharger with a traction drive for mining trucks in the
Andes. Of course it is not the same. It was a planetary but
it used balls instead of rollers and springs instead of the
outer ring providing the spring force.

As a PSRU would be very heavy and prone to fatigue in the ring. The
outer ring is  providing the spring so it is a trade off between function
and life. It is flexing big time with every revolution. It would probably not
save much money if any as the Ford gear set is about $100 bucks brand spanking
new. BTW people have put 2400 hours on the Ford set in a gyrocoptor
with no problems. I don't know why everybody is worried about them.

Paul Lamar ...No rotor no motor.

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