Part 3 rotary steam engine 4 26 2009-3 25 2010.wmv

Giving it a good try!
Attempt to run the prototype of a 2 cylinder rotary steam engine on compressed air.
The need for adequate seals for this unique engine geometry is apparent.
Well it's back to the drawing board, today we have AutoCad and CNN machines and improved seal materials and concepts. ANY SUGGESTIONS out there. Please comment.

Category:

Autos & Vehicles

Tags:

• Rotary engine
• steam engine
• inventions

[kwelch42]

I think you are missing a key point in the sealing properties of the engine. It is a Steam engine and the steam itself is used as a sealant in steam engines. The condensed steam, water, is not compressible and will act as a sealant in a fast moving engine. You are trying to just using air which will just blow past everything. Try putting some water in the cylinders to help seal things up and let it rip....

[rayunseitig]

@kwelch42 thanks for thought. That may well work at some point. I had smothered them in STP and oil, to no avail. Years ago I had a fire tube boiler hook up and had the same issues of steam just blowing by. I had it set up at 100 psi steam and I could feel some attempt to move on the axle but, no go. Thanks again,

Ray

[rayunseitig]

@gordongate That is interesting, now I wish I were an engineer and a master machinist with a lot of cash to play with LOL

One fellow remarked that seals could even be of leather or similiar like 100 years ago. It show there are a lot of ways of doing things, and maybe a few would work.

[gordongate]

@rayunseitig true enough,but there is only one rotor in a wankel and there is an uneven temperature gradient in this engine which requires the cooling system configured to spread the heat more evenly.

I read somewhere that the wankel engine uses a ceramic "piston ring'" to close up the tolerances, the ceramic has negligible expansion and sits in a groove at the tip of the lobes and on the edges,

the cam expands but it is always less than the diameter of the chamber the cam sits in,

[rayunseitig]

@gordongate That makes good sense. However for an automobile application one would not want to wait for the expansion of metals to get going down the road. It seems like the Wankel rotary engines have come to grips with the problems.

[gordongate]

@rayunseitig then you need to know what the maximum expansion is of both cams at max running temp, then you can machine down the meshing surfaces a little further

The drawback is that you would need to let the steam flow warm up the metal first which should seal things up nicely, almost like the fuel tanks on a SR71 Blackbird or a formula 1 race engine.

you might have to find a good cam position and drill and tap out out a bypass hole to let the steam flow in and out until its warmed up.

[rayunseitig]

@gordongate Yes, that would take care of one of the areas of leakeage. Namely the sides. That leaves acouple of other places tho. The inner hub circle agains the outer large circumference of the adjacent rotor AND there the 4 crescent shapes intersect. Also I'm sure closer tolerances would help but not so close as they sieze up with the expansion of heat. Classical engine problems I'm sure.

[gordongate]

@rayunseitig perhaps a version of how piston rings work.

a flat circle ring that sits in a groove cut within the maximum circumference before the lobe protrusion on the pistons and then you can shim the cover plate off by the same amount, it will provide a seal to the rotary piston against the cover plate with a greatly reduced surface area actually in contact against the cover plate..

[rayunseitig]

@gordongate Good thought, thanks for the imput. There are different ways to get the steam or air into the chamber. Perhaps a hollow shaft the delivers the steam into the cylinder cavity thru the rotating piston itself. I was picturing a cone shaped valve and seat with internal slots to regulate the time steam is allowed to pass.

I think an even greater problem is that of seals on the various surfaces vs. the friction they cause.

Thanx again Have a great 2011.

r

[gordongate]

just a thought,

Is the available moving surface area sufficiently large enough for the available air pressure to overcome the inertia.

it just seemed to be a very small volume at the intake position given the friction of those cam side surfaces against the cover plate.

Its still a very nice piece of engineering though,