AlphaGamma

Discussion on Stirling or "hot air" engines (all types)
staska
Posts: 110
Joined: Thu Sep 05, 2013 10:10 am

AlphaGamma

Post by staska »

Hello. I am on 10% of building my firts power producing str engine. Decided to add progress here.

It was inspired by Viktor from Russia (He actually try to build engines for sale, based on v twin compressor) : https://en.energotonyka.com/teploelektr ... na-othodah

https://www.youtube.com/watch?v=2qVDpzNC4hY + other videos

And by Joseph : https://www.frauscher-motors.com/wp-con ... glisch.pdf

Some words on AlphaGamma:

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It have three spaces - hot, cold at 180 degree and cold at 90 degree.

And for my case (300cc hot) + 150 cc each cold space its resulting working geometry is 300cc hot, 212.2cc cold and 135 phase difference. And cold dead space of 43.9cc. Nice and fine geometry for mid. temp engine. And most important - it removes parasitic load from conrods/crankshaft. + balance nicely

Some progress photos:
heat exchanger 100 slots 0.5 x 6 mm 50-60mm long.
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crank case

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Crankhsaft
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Casted parts turning
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And some displacer thin steel welding
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Rendering
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Tom Booth
Posts: 4670
Joined: Tue Nov 07, 2006 2:03 am
Location: Fort Plain New York USA
Contact:

Re: AlphaGamma

Post by Tom Booth »

Alpha gamma. Very interesting.
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Owner
Owner
Posts: 95
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Re: AlphaGamma

Post by Administrator »

Some nice machining there!

Darryl
staska
Posts: 110
Joined: Thu Sep 05, 2013 10:10 am

Re: AlphaGamma

Post by staska »

Sadi, you a wrong. Alphagamma is nothing more than alpha with bigger than 90deggre phase difference and less parasite load on drive mechanism. And it was builded in more than one prototype. I would not comment you invention.
Tom Booth
Posts: 4670
Joined: Tue Nov 07, 2006 2:03 am
Location: Fort Plain New York USA
Contact:

Re: AlphaGamma

Post by Tom Booth »

staska wrote: Mon Mar 29, 2021 3:31 pm Sadi, you a wrong. Alphagamma is nothing more than alpha with bigger than 90deggre phase difference and less parasite load on drive mechanism. And it was builded in more than one prototype. I would not comment you invention.
I tend toward ignoring Sadi's posts more and more as time goes on. He tends to repeat the same long rant with nearly anyone and everyone that happens along. I'm at a complete loss as far as trying to figure out what he's driving at or why.
staska
Posts: 110
Joined: Thu Sep 05, 2013 10:10 am

Re: AlphaGamma

Post by staska »

Tom Booth wrote: Wed Mar 31, 2021 3:28 pm I tend toward ignoring Sadi's posts more and more as time goes on. He tends to repeat the same long rant with nearly anyone and everyone that happens along. I'm at a complete loss as far as trying to figure out what he's driving at or why.
I also did notice this.
staska
Posts: 110
Joined: Thu Sep 05, 2013 10:10 am

Re: AlphaGamma

Post by staska »

Newer, newer and newer use ready made equipment for stirling engine. Its just have too much wrong bore/stroke ratio and is too massive for our power level. You cant make re generator shorter than you stroke, and i was forced to have it at 45mm length.. Where all examples and simulations shows 20-25mm as maximum..

Also - removed connection between gamma and alpha coolers. So gamma do got less optimal, just annular heater/cooler, but it is still much worth, than one extra piston drag... And got some space for internal alternator. Just all looks more tidy...

Next aluminum melt is tomorrow, just do not know which one :)

So - here it goes :
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staska
Posts: 110
Joined: Thu Sep 05, 2013 10:10 am

Re: AlphaGamma

Post by staska »

Tomorrow happens:

Internal alternator taken from china 250w / 36 volts ebike motor. Plus some space left for extra flywheel.
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staska
Posts: 110
Joined: Thu Sep 05, 2013 10:10 am

Re: AlphaGamma

Post by staska »

staska
Posts: 110
Joined: Thu Sep 05, 2013 10:10 am

Re: AlphaGamma

Post by staska »

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staska
Posts: 110
Joined: Thu Sep 05, 2013 10:10 am

Re: AlphaGamma

Post by staska »

https://www.youtube.com/watch?v=OVgVQdbodEM

Pre assembly of heater / cooler / regenerator

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Jagang
Posts: 39
Joined: Sun Sep 27, 2020 5:43 am

Re: AlphaGamma

Post by Jagang »

I get the "alpha" part.
But what exactly is "gamma" about this engine?
staska
Posts: 110
Joined: Thu Sep 05, 2013 10:10 am

Re: AlphaGamma

Post by staska »

Gamma part - it is gamma with very thick displacer rod.

Kind of ringbom engine with displacer made so thick, to produce most of power.

In long description (i think i will make a video on it)

We have one expansion space. And two compression. One is at 90 degree, other is on 180 degree. In sum - its give one compression space with 115-130 degree of phase difference and some addtional dead space. Good for mid temp engine.

But (assumption all work in compression space forced ) that 180 degree space behind expansion pistion gives you two big advantages over normal alpha - its removing a lot of load from you drive mechanism because its acting directly on piston and its give you two smaller piston rings + one displacer ring. In place of two high tension rings..

Other aspect - its adds some dead space but removes that some dead space from cylinder connecting pipe.

And it is fully balanced if pistons/conrod weight is equal

Need my big excel ?
Jagang
Posts: 39
Joined: Sun Sep 27, 2020 5:43 am

Re: AlphaGamma

Post by Jagang »

I'm bad at math, so I guess not. :-P
staska
Posts: 110
Joined: Thu Sep 05, 2013 10:10 am

Re: AlphaGamma

Post by staska »

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The correct fixture to make it 90 degree V twin (milling angle + cylindrical square)

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Hot piston / displacer assembly

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