Sleeve bearing usually require  pressure
lubrication which is a problem in a planet carrier. Needle bearings will
get along with splash. What you are dealing with here is about 456 foot pounds
of torque continuous passing through the planet shafts. 2.85 x 160 foot pounds
= 456 foot pounds.

That is 5472 inch pounds.

If the planet shaft bolt circle is four inches that is 1368 pounds total. Since
there are six shafts... each shaft has a load of 228 pounds. Nothing for a needle
bearing in this size range. Most are rated at 3000 pounds or above working load.

However the planets are really zinging along I think. My guess for the moment
but it can be calculated. I could be very very wrong about that.

http://www.du.edu/~jcalvert/tech/planet.htm#Epic

Leaving that for the moment as an exercise for the reader :)

Getting to the bottom line a full complement 5/8 bore needle bearing has limiting
speed of 6200 RPM. Does not sound like enough. Caged needle bearings on the other
hand have a limiting speed of 21,000 RPM in this size range with a somewhat reduced
working load down around 2000 pounds. The answer is obvious :)

However the life calculations are yet to be made but can be.

Paul Lamar ...No rotor no motor.

   Both Ford and Dodge planets run on needle bearings.
  Ken

Yes but the Fords are not caged. Are the Chrysler planet needle bearings caged?

I think we should build our own simple planet carrier and use hardened and ground shoulder bolts for the planet shafts. Caged needle bearing can then be inserted in the stock planet gears Allison, Ford or Chrysler. The planet carrier
can then be bolted to the aft end of the Lycoming style prop shaft.
Simple straight forward and to the point.

Paul Lamar ...No rotor no motor.

Paul,

Are you aware of this resource:

www.iec.skf.com

You can use this site to calculate bearing life.

Ken Bauman

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

No I was not. Thanks Ken.

Paul Lamar ...No rotor no motor.

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

Ken Welter,

If you are experiencing a short life for the Ford or Chrysler planetaries
it could be because we are running them much faster than Ford does in the trucks
and cars. The answer is to replace the planet's un caged needle bearings
with caged needle bearings. The speed rating for the caged is over three times
as high as the un caged. I'll work on some part number to do this shortly.

I'll need to measure the Ford parts up at the hangar today.

Paul Lamar

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