This could be the answer to the question re a rotary and a hydraulic
     tranny.
     jd

     Tom Kasmer and the Hydristor Featured in Business Week Magazine

     The September 18, 2006 issue discusses hydraulic transmissions in the
     quest to save fuel in its "Science & Technology" section. The full text
     of the article is available online and can be read here
     <http://www.businessweek.com/magazine/content/06_38/b4001082.htm>.

What are they claiming as an efficiency? The killer with most hydraulic
motor/pump combos is efficiency. For use in an aircraft anyway.
Bill Jepson

The weight and heat of driving a prop with hydraulics makes this totally out
of the question on an aircraft. Have you ever seen the size of a hydraulic
pump large enough to handle 300 hp? And the noise..... OMG are they loud. In
the past I tested many pumps on a 50 HP electric test stand, and you thought
a rotary was loud..... And then there is the complexity of pump, motor,
reservoir, pressure filter, scavage filter, case drain filter, controls....
But what a speed brake, as you could stop the prop with the engine running!
Larry

The Business Week author failed to convey the main reason that hydraulic
hybrid systems may make good economic sense.  In a stop and go delivery
truck fleet the hydraulic hybrid system can recover most of the braking
energy that is normally lost.  A hydraulic system can recover about 70%
of  braking energy, whereas the best current electric systems can
recover only about 20%.  Also, for a given power level, a hydraulic
system can be much lighter than an electric system.
The power density for a hydraulic system is around 5000 watt/kg and an
electric system is only around 600 watt/kg.

One possible aircraft use for the technology may be a rocket take-off
assist system that stores water in a hydraulic accumulator and squirts
it out the aircraft tail on take-off.

Aubrey Thompson

Paul,
Apparently the Posa, with all it's problems was a great design - so great in
fact it has been copied by carb designers, Bing, Lectron, Revmaster, Aero
Carb, Ellison and Motorbike carb like Mikuni etc.

They have copied and improved upon the flat slide throttle Posa which was
simpler than all of them. What I like about aircraft carbs is that they have
no float bowel - just a needle and seat.

Personally I can't see how you could get any simpler than this and have been
researching the Posa for a couple of weeks. Apparently the Posa problems
come from the fact they are gravity fed and need some head pressure. Copies
have opted for 1.5 PSI ( pump) to fix the problem with their designs -
simple enough!

So I'm working on a simple slide throttle with a needle that can be adjusted
up and down with a caliper type cable ( for leaning and enriching) and a
lever control (caliper) on toothed wheel to control slide up and down ( with
needle) - all guided by delrin bearings.

Now the only problem I have so far is making the needle seat/ jet variable
flow. I have an idea but don't know if it will work.

Paul this is not unlike your design except for the needle and seat.
George ( down under)

It is easy to say that but what I want to see is a scale 3D drawing.
It is not as easy as it looks.

Paul Lamar

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