Stirlingengineforum.com

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:



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.


crank case



Crankhsaft

Casted parts turning


And some displacer thin steel welding


Rendering

Alpha gamma. Very interesting.

Some nice machining there!

Darryl

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.

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.

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.

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 :

Tomorrow happens:

Internal alternator taken from china 250w / 36 volts ebike motor. Plus some space left for extra flywheel.

welding: https://www.youtube.com/watch?v=rXMoIddEV94

welded : https://i.imgur.com/1dyv4Rx.jpg

Turned in lathe to give final touch.

https://i.imgur.com/eTUfXR0.jpg

https://i.imgur.com/z86RXZU.jpg

~480 cm2 of area.

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

Pre assembly of heater / cooler / regenerator

I get the "alpha" part.
But what exactly is "gamma" about this engine?

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 ?

I'm bad at math, so I guess not. :-P

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



Hot piston / displacer assembly