X-Mozilla-Keys:                                                                                 
Pebvjs@aol.com wrote:

Paul;
You are right the gear loads do cancel out. This allows you to have a really
light housing. Is the sun gear welded or pinned to its shaft? what bearing
life and rpm are you figuring with in the catalog? I am looking at an old SKF
catalog.
Ed.

The bearing life is interminate for the roller bearings as
the loads depend on the type of maneuvers you do
and the moment of inertia of your prop. One can say the 
thrust is such and such and get an estimated life from that.

At 300 FPS (204 MPH) and 200 HP the thrust is about 370 pounds.

The thrust rating on the roller bearing is 1790 pounds at
500 RPM for 3000 hours. The speed factor for 2000 RPM is 0.660.
Best to get the Timken handbook as I have not completely  worked it 
out yet myself. They will send you one quick. Call (949) 455 1521.
I was able to order mine on their web site.
http://www.timken.com/

Ask for the Tapered Roller Bearings Bearing Selection Handbook 1986 
Also ask for a chart showing the weights of the bearings.
I have not found it in the catalog so far.

The Fafnir ball bearing catalog I have is dated 1966 so I need to 
get a new one. Be that as it may the 1500 hour life rating at
7500 RPM is about 430 pounds each. Again it depends on how hard
you push the engine. This is for a 2MM9106WO.

Paul Lamar
 
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