I think what we really need for the torque damper is a fluid
coupling. I was at the Camarillo air show yesterday and they had
an unprecedented collection of war birds. No less than two flying
P38's among many others.

They also had a restored early Northrop flying wing.

I turned the prop both ways  and it rotated freely.
I asked some of the CAF types if it flew in :)
They said yes. They said it had torque converters but
what I really think they meant were fluid couplings.
Maybe they were really torque converters Northrop got in a
junkyard :)

The torque converter is closely related to a fluid coupling
and is widely used in automatic transmission. The stall
speed is about 2000 RPM so the engine can rotate freely
up to about 1500 RPM before a lot of torque is transmitted.

Our problems are not so much torsional resonance but
gear box chatter.

I think a fluid coupling will solve the problem once
and for all.


http://pt.rexnord.com/products/couplings/true_torque_fluid_couplings/fluid-c
ouplings.asp

Falk True Torque Fluid Couplings

A fluid coupling allows the motor to accelerate independently to full
speed,
the driven load has been isolated by the fluid coupling.

Paul Lamar
--


   M-B used them in the supercharger drives of their airplane engines in
WW II.  They controlled the speed of the SC by varying the fill; less oil=
less speed.  With out a lock up clutch, they always have some slip, 2-3%,
that ends up as heat in the oil.  They are a heavy and inefficient way to
go.  In some applications like a soft start for big machinery or an
experimental flying wing with long drive shafts they could be useful.  The
SGF is a little over one pound.

Murry

True. Heavy and inefficient.
I'll bet the SGF does nothing for gear box rattle.
Been there and done that.

Paul Lamar