Hi Paul,



I have been watching your posts on the double reduction gearboxes and am really interested .Can you tell me the rpm of that he guys are using in their engines and what speed they are reducing to.



Does anyone have drawings of a gear housing made up for their Aircraft?

How is the oil circulated through the system and do they run an external cooling system?

Did I read correctly that one system is lubricated by the engine oil system and if so what size reserve is used.

What sort of oil is mostly used is it auto transmission fluid?

What sort of material is used in the damper are there any specifications which my be helpful



Hope someone can help me out here with a few more details



Kind regards

George



They are not double reduction, Just a simple planetary that uses off the shelf $200 Ford
auto transmission gears.

The best ratio is 3.17:1 which allows the p-port rotary to rev to about 8000 RPM
for take off and climb out.

This produce about 260 to 280 HP for the same overall fire wall forward
weight as a 200 HP IO 360 Lycoming. For most experimental aircraft this is
enough power that a constant speed prop is not needed for take off.
This high power gives good cruise speeds above 10,000 feed where
NA engines are down to 70% of sea level power.

The oil comes from the engine oil supply. If  low cost needle bearings are used
throughout very little oil is needed. The best oil is Idemitsu rotary engine oil.

Hundreds of gear boxes have been built using these gear over a
40 year period by various retired vender's. Some made a lot of money building
a selling them :)

Our latest damper design uses RTV silicone rubber.

I have lots of dwg in IGES format if you have
a 3D dwg program

Paul Lamar