Paul
 I am sending you the last design wich is an idea of George Grimes to
 use regular car engine crankshaft main bearings.
 I was looking to use the main bearing of an 10-540 and the price is
 about $300.00 with taxe and you can buy full set of car bearings for
 $35.00 each.

 I am using 4 set of bearing may be is enought or 5 set may be required.
 I looking to secure the planet with the crankshaft with woodruff
 key set
 at 2 or 4 places or splines, and machine longer small gears shaft
 on the
 planet and insert on crankshaft back plate.
 I can use both side of the trust engine bearing but i need an other
 trust bearing on back of the planet face .
 If i go this way i will have to make a mold for a casting.
 Make a look on it and i am looking for your comments.


 *Jean Prudhomme*

 Very clever idea George. I think this will fly. I am impressed.

 I like it.

 It occurred to me to use the stock Lycoming front bearing shell
 but this is better and cheaper.

 I have added some attached 3D's for this type of PSRU to your three
 dwgs.
 I was just going to get a junk Lycoming crank shaft and cut
 off the cracked back of it :)

 You won't need any castings as the housing is 2 pieces.
 I think it can be done out of billet on an NC mill.

 Paul Lamar


 Paul
 On the first dwg i show a possibility to use the trust on both sides of
 main bearing where the oil pressure inlet tap but we have to allow some
 clearance for the prop shaft expansion what do you think ,but we
 need the
 rear trust bearing to hold the planet in place.
 Your comments on woodruf keyway between planet end shaft and the
 prop shaft do i should go with this or splines wich is more
 machining and
 cost?


 *Jean Prudhomme*


 I would not do either splines or keyways. They are not needed.

 Since you plan on machining the prop flange anyway just
 machine the other end with a flange large enough
 to drill and tap to take the pinion bolts/shafts.
 Off the shelf shoulder bolts will work.

 That is the benefit of having a split housing.

 You can then use a stock Lycoming 2 piece thrust bearing shell.

 BTW folks don't get this constant speed PSRU confused
 with a fixed pitch prop PSRU.


 Paul Lamar


 Paul, I can't locate the drawing I sent to Jean with some thoughts
 about a constant speed hollow shaft redrive but will post it if I find
 it. Possibly Jean still has something as a e-mail attachment or drawing
 and can post that. The basic idea is using 2.75 ID automotive
 mainbearings as used in chrysler hemi and big block Chevrolet. One
 thrust bearing is used as a safety backup for the pair of roller thrust
 bearings. just to keep things going if a thrust bearing fails.
There are
 three regular main bearings used with drain lands in the case between
 them. The rear one is for planetary support and the two center ones for
 oil in and out of the hollow prop shaft to allow to be sealed by the
 bearing shells and oil seals beside them. the hollow shaft hs a
bulkhead
 left when it is drilled out to hollow it out. An oil feed to the prop
 is drilled to the center of the bulkhead and an "O" ring sealed tube
 from the center of the bulkhead goes out to the prop flange. The prop
 flange is held on the hollow shaft with a large version of a split lock
 as used on automotive valves. This is necessary to allow oil seals and
 "O" rings to be installed over the front of the shaft and to avoid
a lot
 of machining on the shaft. We were intending to use a vertically split
 two piece symmetrical housing of 398 aluminum. This was so that
only one
 side pattern would be necessary and no casting cores would be required,

 I was intending to use a crank trigger sensor to measure RPM
 and use that to operate a dc variable voltage solenoid driven DO3 sized
 proportional cartridge valve. They are extreme precision valves that
 you screw in a block or manifold and can be as cheap as $29 without the
 solenoid. The oil for the constant speed prop was to come from a tee
 after the oil cooler through a belt drive gerotor pump and go to the
 cartridge manifold which also has two pressure regulator cartridges. A
 high pressure for the prop and a low pressure for redrive
 lubrication.Oil is returned to the engine oil pan.

 As a basic redrive used for a fixed pitch prop it would be no
 lighter than the flight proven design Tracy sells. The advantage would
 be for constant speed and using the transfer case planetary (warner
 4407) a HP capacity for a turbocharged six rotor.

 Jean and his wife stopped by on the way from Canada to Florida so
 I could give him a lesson on how to use Rhino, and we just did the
 redrive as something to draw. A few weeks later I neatened it up into a
 workable design with accurate dimensions for oil seals , "O" rings,and
 bearings etc and sent it to his e-mail. Jean was still at that time
 determined to use inboard mounted engines with 90 degree drives on the
 wings for his scale piaggio project. I will likely design a PSRU based
 on these ideas after getting something done on airframe construction.

 george grimes

 It would be great if I had a Rhino on this. This is all I got
 from Jean. Let me know if you do not get 3 attachments with
 this message.

 Paul Lamar

 Yes Paul i found it there is as attachement
 The complete set from SUMMIT part # MS-829 H HIGH PERFORMANCE TOTAL
 PRICE $79.95 PLUS $9.95 WICH IS A MAIN TRUST BEARING AND 4 REGULAR
BEARINGS
 I revised the Georges drawing and he is right to use only one trust and
 all other as flat bearings it will be much easyer for machining and
 lower cost.


 *Jean Prudhomme*

 OK Jean. Thanks. Why the space between Chevy V8 bearing shells?
 Why not just butt them together?

 Paul Lamar

Each grooved between each bearing act as way out of oil pressure and
faster oil circulation ,the shaft have better support by spacing the
bearings and if we butt them all it can have some spot of lack of
lubrication.
If you look on the 10-540 they do have large grooved for better
lubrification.
One of the groove does not have a way out to hold the gorvernor oil flow
for constant speed prop
I am correcting my sketch with 4 flat bearings and 1 trust bearing
similar as George design

*Jean Prudhomme*


There is one groove at the feed hole in the Lycoming shell.
The oil pressure fed into the front bearing is over 100
psi because that is what the constant speed prop requires.
That oil pressure comes from an auxiliary boost pump
in the prop gov. Normal oil pressure for a piston engine
is only 40 psi.

The long shell helps to retain that 100 psi pressure. If you narrow
the shells that high oil pressure will bleed off around
the edges. If you are going to use the V8 main bearings
I would butt them up to each other to maintain the prop oil
pressure.


Paul Lamar


Paul, bearings such as clevite 77 have a grove for full time oil flow.
There is very little restriction to oil flow from the housing thru the
groove into the hollow prop shaft. Some oil through the bearing clea
rance (.0015 is stock) is needed for lubrication and cooling of the
bearing. This goes into the grooves between the bearings and out the
case drain with the other lube (low pressure) oil. If not exhausted by
having the shells butted up there would be 100 psi oil on the end of
housing seals. Having a small continuous flow is also beneficial for the
prop control valve. If it is operating at a continuous low flow rate
input corrections will be smooth. If it is going from sealed off to
flowing there will be a pressure change downstream of the valve and
seeking of the prop pitch as it seats and unseats. If the constant speed
is pilot controlled with a balanced piston relief valve and a vernier
needle valve no electronics would be needed.  This would be an
adjustable pitch whereas using the rpm counter to generate a dc voltage
would be a constant speed.

george grimes

To be on the safe side I would spend the bucks and use the
tried and true Lycoming shells. Sometimes one makes the smallest changes
and un-anticipated side effects or consequences occur :)

Paul Lamar