alpha bellows

Discussion on Stirling or "hot air" engines (all types)
vamoose
Posts: 275
Joined: Tue Jul 03, 2012 12:16 am
Location: Australia

Re: alpha bellows

Post by vamoose » Fri Feb 08, 2013 8:01 pm

Here is a great example of the use of bellows in Stirling engines by Approtechie. Its not an Alpha engine, but is a Gamma configuration with twin displacers for each power piston.

The second video provides enough information for anyone who wanted to try and duplicate his fantastic effort.

Six-cylinder Stirling engine
http://www.youtube.com/watch?v=bhTcbg7wujo


Making a 6-cylinder Stirling engine
http://www.youtube.com/watch?v=lvvyjJ8wz3Y

Its worth checking out some of his other videos on his channel if you have the time.

vamoose

Ian S C
Posts: 2221
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: alpha bellows

Post by Ian S C » Sat Feb 09, 2013 2:29 am

I have an interesting little set of bellows, in the form of an old (not sure how old) automotive thermostat, it would have a stroke of about 1/4", I'v had it a number of years, and have not got round to incorperating it in a motor. It might form the power side of a free piston type motor. Ian S C

vamoose
Posts: 275
Joined: Tue Jul 03, 2012 12:16 am
Location: Australia

Re: alpha bellows

Post by vamoose » Mon Feb 18, 2013 10:16 pm

Hey Guys,
Here's another engine using a bellow for a power piston, sorry, again its not an alpha setup.

'Stirling engine and rocket stove -test run'


vamoose

derwood
Posts: 113
Joined: Sat Dec 11, 2010 10:15 pm

Re: alpha bellows

Post by derwood » Mon Apr 08, 2013 2:34 pm

You might find this interesting.......


Hopper
Posts: 54
Joined: Fri Feb 08, 2013 6:54 pm

Re: alpha bellows

Post by Hopper » Mon Apr 08, 2013 9:18 pm

It's hard to tell from your video but it looks to me like part of the problem may be too much friction and too much reciprocating weight.
Is that main crankshaft bearing a ball bearing? What about the connecting rod bearings? They all need to be almost totally friction free for a Stirling to work on the low temp difference you are looking for.

Those connecting rods and their bigends look way, way too big and heavy for the power output of an engine like this.
Look at the "Rcoket Stove LTD" video posted above and see how tiny and lightweight his rods and crank etc are. And made from aluminum.

Try using micro ball bearings out of a computer hard drive, video player, small electric motor etc for bearings and connecting rods made from 5or 6mm diameter bar with aluminum end fittings. Even your crankshaft itself probably only needs to be 8 or 10mm diameter.

What you currently have would be great for a 5 horsepower engine spinning that motorcycle wheel, but you are going to be lucky to extract even a tenth of that power from a Stirling like this.

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