I wonder if anyone can shed some light on this issue. I had assumed that
the rotary would have considerably less torsional vibration than a
piston engine -- for a number of reasons -- but I have heard this may
not be so.
Also, how does the single-rotor engine fare in this regard?
Regards,
Gordon Arnaut
Ontario, Canada.
The two rotor is better than a four cylinder. About the same as a six
cylinder.
The one rotor is a real beast. See the attached graphics.
Paul Lamar
I had my 13B run for few seconds on one rotor and it was shaking so bad, my
teeth were rattling:). If one rotor quits you'll know it.
Bulent
I have heard that said and on the other hand Tracy and I were watching
Joe Schiferl start up his Power Sport 13B powered Velocity at
OSH and Tracy supposed it was running on only one rotor from the sound
it was making. It did not seem to be shaking.
Many one rotors have been built and when properly balanced they don't
apparently shake. They appear to be smooth. I don't really think you
can feel or see torsional vibration at anything over 1500 RPM or so.
The prop connection sees it for sure as that is why a Lycoming is so
hard on props. In theory there is no up, down or back and fourth
shaking forces.
Perhaps there is something else going on in your engine.
Its a mystery.
next message ------------------------------------------------
Duh! I just think I figured it out. When the two rotor runs
on one rotor the pulse rate is below Tracy's rubber torque pulse isolator
resonant frequency. Tracy's latest rubber torque pulse isolator is
smooth down to 1000 RPM or so according to Tracy running on two rotors.
The Power Sport PSRU uses a direct connection to the gear box. No torque
pulse isolator.
The old Ross clutch spring plate torque pulse isolator had a higher
resonant frequency and therefore one had to keep the engine idle above
1800 to 2000 RPM or it would shake and shutter badly.
Come to think of it when we were running the p-port engine on
the dyno recently it would occasionally run on one rotor for various mixture
issues with no apparent vibration. It too of course was directly connected
to the dyno water pump load with no torque pulse isolator.
Paul Lamar
The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site.
http://www.rotaryeng.net
Copyright 1998-2005 All world wide rights reserved.