Fred Osborn wrote:

 Paul,

 I understand that the rear journal e-shaft bearing is not suitable
 for the side load imposed by a cog belt drive. For a single rotor
 engine how about a needle bearing which would run between the
 e-shaft and a reworked or redesigned rear synchronizing gear
 replacement part. Could that arrangement provide an adequate
 side load capability? Rotor sync would be maintained by the front
 sync gear.

 Fred Osborn

Ken Welter uses an outboard support bearing with simple oiler.
Needle bearings have severe RPM limitations. I would use a precision
ball bearing in that application.

Paul Lamar

   I use a needle roller, Torrington # HJ-202820 which has a speed
limit of 14000 rpm.

   Ken

Yes it does but that is at zero load :)

Lets see an HJ 202820 has a Torrington basic dynamic load
rating of 7400 pounds. That is what they call C sub r
You use that number to enter this chart with the real load and
the RPM and figure the life. What is the diameter of the lower
pulley. I need that to figure the radial load at 300 HP take off
and at 150 HP cruise.

I also need the RPM at 300 HP and the RPM at 150 HP cruise.

It helps that the bore of an HJ 202820 is only 1.2500 inches in diameter.

I assume the shaft is Rockwell C 58.

Paul Lamar

BTW as a ball park number since the speed factor at 7000 RPM is 5 a belt 
tension of 1480 pounds will yield a life of 500 hours. 10% of a batch of bearings
will fail and 90% will live to 500 hours.

Paul Lamar
 
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