I do not know all of the restrictions to the application of the fluid
coupling, but if you are looking for something that will absorb "chatter"
and does not generate a lot of heat, have you considered the Dodge
coupling
that Molt Taylor used in the IMP and mini-IMP?

http://www.dodge-pt.com/products/pt_components/flexidyne/flexidyne.html

I had heard at one time the company was not "aviation" friendly due to
liability issues.

Just a thought.

K. Carl Milbrodt PE


As far as I can figure it out they are limited to 1800 RPM
and they are very heavy. We need something that will survive 7500 RPM


Paul Lamar
--

A Flexadyne is a centrifugal clutch.
Bud Warren used a centrifugal clutch on his gear drives. A single plate
with weights with ramps and rollers to clamp up instead of the springs in a
normal clutch.
 Most centrifugal are drum type rather than disc. Disc is likely better
for high rpm.  The SGF coupling is the lightest, simplest, least expensive
and quickest way to deal with the drive line vibration.  Do you think that
Porsche, M-B, BMW, General Motors and the other car companies that use them
are guessing?

Murry I Rozansky



The rubber couplings really don't deal with low RPM aircraft gear box chatter.
Their real function is to mitigate the torque pulses effect on the gears.
What we need is both but I have not come up with a light weight
fluid coupling or a centrifugal clutch yet. In the mean time we will
continue to idle the rotary at 1800 engine RPM or higher. After all the
prop is only turning 632 RPM.

Paul Lamar