PSRU design advantages

George wrote:
Richard Lamb wrote:

ADK wrote:

IF you had to design a PSRU, to drive a pusher propellor via shaft,
what would your experience dictate? Thinking along the lines of a
gearbelt, chain or gear. Please, I would appreciate the collective
experience available on this group. I have decided on the aircraft,
but want to make it the most reliable and safest it can be.

"ADK" wrote in message
news:X6TXf.28774$%H.11944@clgrps13...

This is probably going to open old wounds. What I would like is
experienced input on the advantages, for economic, efficiency and
longevity etc. of different types of redrives.

I am leaning towards a cog-belt reducer in a 6 cylinder, liquid
cooled, configuration driving a long drive shaft to the prop.




The collective experience is zilch = nada = squat = undefined.

THAT is what everybody had been trying to tell you.

Wait a second. Look around the airport.

How many shaft driven propellers do you see?

Have you ever seen?

If you are heart set on doing it, I sincerely wish you luck.

But I can't offer any further advice - 'cuz they ain't none...



Richard


Richard,

Didn't the military do this once?? Seems there was the P-39 Aircobra,
shaft driven from a rear mounted engine?? Are the gray cells working
that far back??

Not that it would be applicable to an experimental, but at least It was
once done?

George

Wasn't the gub'ment, George, but Bell Aircraft.
P-39 not only had a drive shaft but a cannon firing thru the psru gearbox.

layout of engine, gearbox and cannon at:
http://www.home.earthlink.net/~tp-1/p392.jpg


So it *can* be done.
(The cannon firing thru the prop! )

I was curious to see if Bell had reduced the shaft RPM between the engine
and gearbox, but it looks like 1:1 there.

That might have been of interest to the OP, since his setup will likely
drive the shaft at prop rpm (after the psru).

Gonna take one tough (probably spelled h.e.a.v.y) shaft for that service...


Are there any others?


Richard