Best Role for Alpha, Beta and Gamma Stirling Engine Configurations?

Discussion on Stirling or "hot air" engines (all types)
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yeehi
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Joined: Fri Jan 26, 2018 3:34 am

Best Role for Alpha, Beta and Gamma Stirling Engine Configurations?

Post by yeehi » Fri Jan 26, 2018 6:16 am

There are 3 main configurations for Stirling Engines: Alpha, Beta and Gamma.

To which sort of application is each configuration best suited? For example, might one of them be preferred at higher temperature ranges or might one be better suited to more rapid motion? Or perhaps is one an improvement on another?

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

Re: Best Role for Alpha, Beta and Gamma Stirling Engine Configurations?

Post by Ian S C » Sat Jan 27, 2018 4:01 am

yeehi, the GAMMA and BETA motors are actually the same, just that the BETA is more compact, every thing packed in the one cylinder.
The ALPHA motor is still quite similar, except that both cylinders generate power. The hot piston has an extension that is of similar construction to a displacer, this is call a Heylandt Crown.
Probably the best motor to start with is a V type GAMMA motor, this has the added advantage of only needing one crank pin for the two con rods.
Ian S C

Wellington
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Joined: Mon Apr 18, 2016 4:02 am

Re: Best Role for Alpha, Beta and Gamma Stirling Engine Configurations?

Post by Wellington » Mon Jan 29, 2018 10:05 am

Ian S C wrote: Probably the best motor to start with is a V type GAMMA motor
Ian S C
Hello Ian. What is the difference between a v type gamma and a v type alpha?
Wellington

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

Re: Best Role for Alpha, Beta and Gamma Stirling Engine Configurations?

Post by Ian S C » Tue Jan 30, 2018 4:28 am

The V type GAMMA motor has a power piston , and a displacer, with a volume ratio of 1 : 1.5, the ALPHA motor has a hot and cold piston, and a 1 : 1 ratio. There is a bit more work on the ALPHA motor as you need to make two fitted cylinders and pistons.
With a V type of motor, for spirit firing it's best to have the displacer vertical, and hanging down, and if gas fired it is best if the hot end is pointing up. These positions take the load off the rod as it passes through the gland, reducing friction by quite a bit. The down pointing hot cap can be heated by meths or gas, but its hard to use meths on an upward pointing hot cap.
Ian S C

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