Do yourselves a favor and search out an Enstrom helicopter to study
   their system. It has been in use for a very long time with great
   success. Enstrom uses the belt as the clutch and this solves the tension
   problem for Enstrom. The polyV provides damping of torque pulses. The
   system should be no more complex nor heavier than a cog belt system with
   the exception of the tensioning device.

   This past Saturday I examined the "Belted Air Power" unit on a V8
   engine. It is quite clean and in use for a long time. However I want
   to use the polyV belt system as I think there is less risk of
   catastrophic failure. With the cog belt improper tensioning can raise
   havoc with the belt teeth. The cog belt may not provide the damping
   qualities of the polyV belt.

   Bob Y

   There are way more Robinsons flying then Enstrom :)
   Probably a 100 times as many :)

   The V-ribbed provides damping too. Probably it is more efficient
   than a poly V as the belt is thinner so there is less
   flex and heat build up. However not recommended for a clutch type
   helicopter application.

   Paul Lamar ...No rotor no motor.

----------------------------------------------------

Bob,

That's my thinking exactly -- I would much rather go with v-ribbed, or
even multi-v, than cog belt.

The difference is that an improperly tensioned v-belt will merely slip,
while the cog belt will quickly self-destruct.

A cog belt will still provide some torsional damping, just as a chain
drive will, but v-belts are better in this regard too.

I really can't understand why cog belts are so popular. The only time
you really need them is when you need synchronicity, which you don't
with a prop drive. Otherwise they bring a lot of negative baggage.

Regards,

Gordon.

The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net
Copyright 1998-2006 All world wide rights reserved.