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Compressed air engine
Posted: Wed Jul 27, 2011 3:55 pm
by Gun Freak
I'm trying to design a compresses air engine but I cannot wrap my head around how they exhaust the air in the cylinder in order for the piston to retract. Is there some sort of valve connected to the crank shaft that opens and closes? I can't find anything online.
Posted: Wed Jul 27, 2011 4:05 pm
by jackssmirkingrevenge
Re: Compressed air engine
Posted: Wed Jul 27, 2011 4:06 pm
by velocity3x
Gun Freak wrote:Is there some sort of valve connected to the crank shaft that opens and closes? I can't find anything online.
A good valve example is the linkage on a steam locomotive.
Re: Compressed air engine
Posted: Wed Jul 27, 2011 4:09 pm
by jackssmirkingrevenge
velocity3x wrote:A good valve example is the linkage on a steam locomotive.
A bit more
complex but worth a look, great website to browse through by the way.
Posted: Wed Jul 27, 2011 4:20 pm
by Gun Freak
Now I need to figure out a way to implement that, but for lower pressure.
Posted: Wed Jul 27, 2011 4:27 pm
by jackssmirkingrevenge
Why should pressure have any bearing on the design, other than ensuring a sufficiently wide piston to provide the requisite torque?
Posted: Wed Jul 27, 2011 4:34 pm
by Gun Freak
Well I just thought of a new design that doesn't need high pressure. A linkage runs off of the crank thank opens a small intake valve when the piston is I'm the retracted position. I think it is very promising but I need to draw up some sketches and hopefully one in 3D. I might post it.
Posted: Wed Jul 27, 2011 7:41 pm
by ramses
Some of the more complex engines use variable valve duration to either fully expand the steam (air) for economy, or pump in full pressure steam for much of the power stroke for more peak power.
Do you feel like attempting something similar?
Posted: Wed Jul 27, 2011 7:47 pm
by Gun Freak
How simple is it to construct that mechanism? I'm going to use this engine as a model but it will be a bit different. I'm just using the same valve setup.
http://npmccabe.tripod.com/coathngrengn.htm
Is it possible to vary the valve duration on this design?
Posted: Wed Jul 27, 2011 7:50 pm
by warhead052
Now I regret throwing out my old lawn mower engines. Try adding an air input line where the spark plug would normally go on a regular engine. And fill it with air, if it rotates then you have an air engine. You just have to drill a hole to let the air out.
Posted: Wed Jul 27, 2011 7:52 pm
by Gun Freak
It's not that simple lol.
Besides... The whole point is for me to build a model engine, for the fun. I'm also making a Stirling engine.
Posted: Wed Jul 27, 2011 8:08 pm
by warhead052
Ohhh, model engine. I thought you meant like an actual engine.
It may be that simple, I just haven't tried it. Soon as I see a neighbor throw out a mower I will try it though.
Posted: Wed Jul 27, 2011 8:11 pm
by Gun Freak
Cool, search on YouTube for Theairgunman. He has a video of a converted engine that runs on air/steam. Worth checking out.
Posted: Wed Jul 27, 2011 9:17 pm
by warhead052
Yeah, I am subbed to him. Its a pretty cool engine.
Posted: Wed Jul 27, 2011 9:27 pm
by Gun Freak
I'm subbed too! He did a very cool idea on his conversion.
