This might be useful for low power stirlings

Discussion on Stirling or "hot air" engines (all types)
Aviator168
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This might be useful for low power stirlings

Post by Aviator168 »

Tom Booth
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Re: This might be useful for low power stirlings

Post by Tom Booth »

There is another similar video:

https://www.youtube.com/watch?v=dl_eP3c4gD8

Seems like it could be a good way to convert a reciprocating motion into a rotary motion very effectively as well as vice versa.

There appears to be a 2:1 ratio between the inner gear and the outer gear ring.

I wonder what the intended purpose of the thing might be.
Aviator168
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Re: This might be useful for low power stirlings

Post by Aviator168 »

I wonder what the intended purpose of the thing might be.
Complete elimination of side load and there are other benefits for IC.
BTW. This is not new at all. Look at this 1802 steam engine.
https://www.youtube.com/watch?v=zMSlK5nH6HA
Tom Booth
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Re: This might be useful for low power stirlings

Post by Tom Booth »

That gearing may very well solve a problem I've been working on. I want to build an LTD type Stirling that will power an air compressor. It would need to be geared down. This type of gearing looks like a very elegant way to accomplish that without a lot of loss due to side load.
Aviator168
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Re: This might be useful for low power stirlings

Post by Aviator168 »

That large gear is fixed.
Tom Booth
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Re: This might be useful for low power stirlings

Post by Tom Booth »

What I had in mind was something like this engine:

https://www.youtube.com/watch?v=ARD3ctp80ac

but I wanted to somehow attach a very small compressor or air pump. Something very simple, similar to a bicycle pump. This type of gearing looks like a very smooth way to accomplish that.
Tom Booth
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Re: This might be useful for low power stirlings

Post by Tom Booth »

Compressing air generates considerable heat. Releasing that compressed air results in cooling.

What I have in mind is to have an LTD type Stirling (Or any Stirling Engine for that matter) power an air-cycle heat pump.
Aviator168
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Re: This might be useful for low power stirlings

Post by Aviator168 »

That's a low temperature deferential engine. What kind of power requirement are you talking about?
Tom Booth
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Re: This might be useful for low power stirlings

Post by Tom Booth »

Aviator168 wrote:That's a low temperature deferential engine. What kind of power requirement are you talking about?
No specific power requirement particularly.

Just make the LTD big enough and the air pump small enough that the Stirling Engine can run the air-pump or air compressor.

The compressor or air pump doesn't have to power anything. It's only purpose would be to generate some heat and cold so as to possibly increase the temperature differential.
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Re: This might be useful for low power stirlings

Post by Tom Booth »

To Illustrate:
LTD_with_air_cycle.gif
LTD_with_air_cycle.gif (27.1 KiB) Viewed 14154 times
A simple LTD Stirling with a little air-pump for an air-cycle heating and refrigeration unit.

That is of course simplified.

The hot and cold heat exchangers would consist of coils of tubing looping around the top and the bottom of the engine rather than straight pipe.

There would also be some insulation to keep the heat and cold supplied to the engine rather than dissipating to the surrounding air.

The expansion valve would probably be a little turbine with some kind of load to help reduce the temperature of the expanded air.
Aviator168
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Re: This might be useful for low power stirlings

Post by Aviator168 »

A perpetual machine?
Tom Booth
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Re: This might be useful for low power stirlings

Post by Tom Booth »

Aviator168 wrote:A perpetual machine?
Presumably no matter how feeble the engine, it could operate some kind of little air compressor. So some warming and cooling effect above and below ambient should be possible, if for example the engine were started initially by setting it atop a block of ice. Something would have to get it started.

I don't think it would be proper to call it "perpetual motion" if it worked at all, as it would have the "latent heat" in the air as an energy source. It could not work outside of the earths atmosphere or without warmth from the sun putting heat into the air in the first place. In other words it would be making use of latent solar energy. It is not a "closed system" and so could not work in a vacuum or in outer space, as would true perpetual motion.

I think this is, by many, considered an example of "perpetual motion of the 2nd kind". Personally though, I wouldn't call it that, It might enhance the operation of a Stirling, I think. by lending some additional heating and cooling to it, above whatever is supplied to get it going to start with. I think it would be worth experimenting with, if for no other reason then that Tesla suggested that an engine with such an arrangement could become "Self Acting".
Actually some pre-cooling coils might help bring the temperature down on the cold side prior to the air passing through the expansion valve or throttling valve or turbine or whatever.

Like :

LTD_with_air_cycle2.gif
LTD_with_air_cycle2.gif (30.38 KiB) Viewed 14152 times
Ian S C
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Re: This might be useful for low power stirlings

Post by Ian S C »

(1) You realise that a simple LTD motor, what ever size barely has the power to operate, let alone drive anything.
(2) Get a bike pump, and see how much energy you require to increase the temperature of the air, hold your finger over the end. To make any noticeable heat increase you will exert quire a few Watts.
Ian S C
Aviator168
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Re: This might be useful for low power stirlings

Post by Aviator168 »

Don't look down on these LTDs. Large enough, they can generate considerable power.
https://www.youtube.com/watch?v=duuk_r--lqU
Ian S C
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Re: This might be useful for low power stirlings

Post by Ian S C »

The power is still going to be measured in Milli Watts, rather than Watts.
Ian S C
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