Paul
    There is the alternate design with ball and roller bearings,


    Jean Prudhomme



    Jean, I am a little concerned about using a single tapered bearing. A
    radial load creates a thrust component in the bearing. This is usually
    countered by an oposing tapered bearing. Some way of establishing the
    preload or clearance on the bearings will also be needed and a bushing
    or bearing where the propshaft fits into the input shaft because there
    is a 2.85 to 1 speed difference. The retaining nut holding the deep
    groove ball bearing spacer and gear could use a locking device such
   as a
    "W" washer with a tab into a recess in the shaft and a notched
   spanner nut.
    The journal bearing design looks to be better from a load
    bearing capacity, the ability to be a tractor or pusher
   installation and
    provisions for separating lubrication oil pressure and the higher prop
    control pressure. The bearings seem to be further back from the prop
    flange than necessary as reguards overhung load. This may not be a
    concern due to the large diameter of the propshaft.


    george grimes

    Yes Georges i was wondering about the load at the flange side and it
   could be a roller bearing instead of taper roller or two deep grooved
   bearing.
   I do have all materiaL to built the alternate and less work.
   Regarding the journal bearing model will be machined by a friend of mine
   in Olando he does have 3 axes mill so we can bill the housing from 2
   rectangular alum block,this is my intend of using a recess lock washer
   be lock by the keyway on the shaft, i was wondering about the adding an
   other journal behind the flange but it will be a longer span for the
   complete unit ,do you think i should add an other journal or go that
   way???
   My project is delay due to Real Estate sale with CDN and their money
   even, i do sale an average one property by week plus homes inspection
   but i guess it will slow down on april when all going back home and then
   i will invest more time on my project.
   You see i still work with Alibre but i start to learn the RHINO but it
   will take time before i can do a full design with it.
   Thank,s George for your assistance and knowledge

   Jean Prudhomme



Jean, A two row  deep groove angular contact bearing might be workable
to take the thrust and radial loads. The simulator is showing a little
under two pounds of thrust per HP static and about one pound per HP at
cruise power with a constant speed prop. A  roller bearing doesn't take
thrust and a spherical roller bearing requires a significant radial load
to have thrust capacity.

      As far as your journal bearing type goes it appears plenty strong
in bending loads from gyroscopic effects due to the large diameter. I
was just wondering if the governor pump gears could be further back in
the stack leaving a journal bearing out near the prop flange. I wouldn't
think you would want to add a prop shaft extension with the pusher props
behind the main gear due to ground clearance concerns, so the present
bearing locations are  fine.   Just for clarity we are considering two
designs and are not talking about mounting roller bearings and journal
bearings on the samr shaft due to their different operating clearances.


george grimes