David Carter wrote:

Paul, Great idea.  I've embedded a couple of "design evolution"
questions/observations in the text of your quoted msg below.

David Carter

   Paul, is there data on the flow rate of these pumps with some known
liquid?  If so, we could extrapolate to w stroke oil viscosity and
calculate flow. Beyond "calculations", I'm sure that we'd 
want to actually "flow" these
things in a test bench environment to "verify" that our critical apex
seals were going to be properly lub'd.

Absolutely. As I mentioned these are experimental. You need to get
one and test it. Any transformer that puts out 12-16 volts AC
will  work. A 12 volt AC door bell transformer comes to mind.

    Paul, would these pumps be flowing oil so we'd have to have oil
lines to and from cockpit?

Yes they would but the oil lines are under very low pressure
and they are very small. Perhaps only 1/16 to 1/8 inch ID.
You don't need them in the cockpit but rather than instrument
them, to see if they are working, put them in the cockpit and feel
them. If you feel a vibration they are working. Also if you 
maybe see bubbles moving in the transparent plastic lines they
are also working.

If the oil tank is also plastic, clear and in the cockpit 
you can tell if you are running out of oil. Lots of airplanes
have gasoline catch tanks behind the instrument panel with 
sight gages.

  How would we know if a pump failed?   I'd want a cockpit
indicator/warning on anything electronic/electrical (as opposed to
bulletproof mechanical like existing metering pump).

 I'd want dual redundant pumps because a single pump would result in
failure of one of my two rotors and cause damage to the rotor housing.
(like old Mercury outboards with 1 carb per cylinder:  If one carb's
fuel flow was plugged by foreign matter, that piston would seize,
stopping the entire engine.  We'd probably just suffer loss of 1/2 power
in 13B.

Carry a spare in the cockpit. Unplug the bad pump and plug in the new
one.
It is highly unlikely that these pumps would fail. They have two moving 
parts. A ball check valve and a solonoid plunger. There are no brushes
or motor bearings. The bridge transistor take care of reversing
the voltage across the solonoid giving it the pumping action.

You could even make your own out of a speaker coil and magnet with 
out too much trouble. We are talking real low energy for this
pump. When is the last time a speaker failed in your house? 

IMHO the existing mechanical pump has a real problem when feeding it 
oil from an external tank. You somehow have to plug the drilled
passage in the front cover and get oil into that same passage 
downstream from the plug. Perhaps a spacer and a new drive shaft. 

If you separate the pump  from the front
cover you will have to design and machine a shaft, bearings,
seals and cog belt drive not to mention a way of attaching
a feed hose to the pump. IMHO If you are going to do that
a simple gear pump is much easier to design and machine.

If it was me I would forget the whole thing and mix the 2S 
oil with the fuel.

PL
 
The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org