Alpha Stirling Design - What dou you thing?

Discussion on Stirling or "hot air" engines (all types)
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gui_amuchastegui
Posts: 7
Joined: Sun Feb 18, 2018 5:09 pm

Alpha Stirling Design - What dou you thing?

Post by gui_amuchastegui » Mon Jul 09, 2018 1:02 pm

Hello,
What do you thing about the design of the alpha stirling engine that I am doing (see attached file)?

My main question, are about the heater, regenerator and cooler.
Do you have any comments and suggestion? Can I improve this design?

Best regards,

José Guilherme
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Ian S C
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Location: New Zealand

Re: Alpha Stirling Design - What dou you thing?

Post by Ian S C » Tue Jul 10, 2018 5:40 am

An interesting looking motor, how are you going to heat it?
Here is my one, it has a Ross Yoke. 35 mm bore, and 22 mm stroke, air cooled, and gas / LPG heated. That's a 6" / 150 mm rule standing on the right hand side, it caught the sunlight a bit.
Ian S C

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gui_amuchastegui
Posts: 7
Joined: Sun Feb 18, 2018 5:09 pm

Re: Alpha Stirling Design - What dou you thing?

Post by gui_amuchastegui » Tue Jul 10, 2018 1:44 pm

Nice one Ian S C, congratulation for your job.
I tried to design a Ross Yoke, but I wasn't able.
Dou you see benefits over the "regular" crank shaft?
What about your regenerator? How it is look like?
I am going to heat using a torch.

Ian S C
Posts: 2150
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: Alpha Stirling Design - What dou you thing?

Post by Ian S C » Wed Jul 11, 2018 5:19 am

There is no difficulty making the Ross Yoke. I have changed that motor from having a link from the bottom centre to the (in this case) right hand side, to having a pin on the bottom centre of the triangle running in a vertical slot.
It also has been changed from water to air cooling.
There is no fancy regenerator system, just a fairly long Heylandt Crown on the hot piston, and a 1/4" X1/4" slot connecting the hot and cold cylinders, the cylinder head is aluminium (was mild steel). Hot cap and Heylandt Crown are stainless steel.
Ian S C
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gui_amuchastegui
Posts: 7
Joined: Sun Feb 18, 2018 5:09 pm

Re: Alpha Stirling Design - What dou you thing?

Post by gui_amuchastegui » Sun Jul 15, 2018 12:14 pm

Ian,

Thanks for the answer.
I didn't understand what is a "fairly long Heylandt Crown on the hot piston"? Do you have any picture of that?
Do you have a drawing of your engine? I would like to understand better the path of the fluir during its operation.

Best regards

Ian S C
Posts: 2150
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: Alpha Stirling Design - What dou you thing?

Post by Ian S C » Mon Jul 16, 2018 4:56 am

I didn't know and could find no information about Heylandt Crowns, so I made mine to similar dimentions to the displacer in a GAMMA, or BETA motor, so it's length is 3 x the diameter. The two cylinders are joined by a hole drilled through from the r/h side of the cylinder head (the bit that goes right across the top of the water jackets. The hole is plugged at the r/h end, I think it is about 6 mm dia., in the original design. As the motor is now, the cylinder head is in two pieces, and a 6 mm slot is milled 6 mm deep and an aluminium plate is placed over this and bolted up. I don't work to drawings, some times I will make a sketch of a part to see how it fits, unlike a lot of modelers today who do the whole motor in 3D on the computer before they cut metal. First I find what metal I have, I buy as little as possible, the only screws I buy are Alen head cap screws, the others I make myself. The hot cap, Heylandt Crown, or displacer get the end TIG welded by a friendly Tigger(he doesn't do it for free). Most of the steel, and cast iron that I use is scrap metal, I usually buy the aluminium.
Ian S C

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