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electric bike

PostPosted: Sun Aug 24, 2008 11:43 am
by mike57
What are the possibilities of a design of Stirling engine small enough
to carry on an electric bike? the bike's motor is 200W and the
Stirling would be used to power a generator to keep the battery topped
up- so slow starting problems of a Stirling would not be a problem.
The Stirling engine would have to be capable of turning a 36V
generator to produce 5Amps and be small enough at least to be easily
mounted in a bicycle pannier arrangement.

Response to electric bike

PostPosted: Sun Aug 24, 2008 12:39 pm
by bptdude___2569

Hey Mike,

The internal combustion engine became what it is in our world, becuase it was smaller, lighter, and more versatile. The Stirling engine is the opposite of these things, and probably abou the worst choice for such an application as a bike.

But, hey, if you can do it, go for it.
Many people would like to see that one!


There is a working prototype fuel cell motorcycle.
The only problem so far, beside lack of available hydrogen fuel, is that it is so silent, some people want to mandate minimum noise levels for safety, which has started yet another source of social debate.

- Joe

Response to electric bike

PostPosted: Sun Aug 24, 2008 1:26 pm
by mike57
Hi Joe thank you for your reply to the above. The reason I wanted to use a Stirling for this application is that an IC engine is noisy and smelly. I could quite likely make a small steam engine to do the job, but then I would have the problems of carrying a boiler on a bike.
But just imagine having an electric bike with practically unlimited range, the battery being constantly topped up?

Response to electric bike

PostPosted: Sun Aug 24, 2008 4:30 pm
by bptdude___2569

Well, good for you, for dreaming and thinking, we all do that, and always good to see others do it.

I wish I had the link for the fuel cell motorcycle. It was not noisy, and not smelly. The output was only water vapor. It was also extremely quick off the line, so much so, they had to slow down the electric motors so the test drivers would not hurt themselves.

One of these days, if sanity ever prevails, every other form of energy will be converted to hydrogen. Astonishinly, even people like Sen. McCain have not made the connection between the dozens of new nuclear plants he wants to build, and the ability to manufature fuel, no just supplent the electric grid.

In this, the Stirling engine, or some new variation of the externally heated heat engine, will be of value beyond description. This is because it will allow many unconventional sources of energy to be used to make hydrogen.

The original Stirling was motivated by the need to build replacements to the steam engine, because the steam engine was just too dangerous. Ironically, nuclear power is too dangerous mostly because they use a big steam engine. Both Three Mile Island close call and Chernobyl were steam and water mishaps.

A dry nuclear design that could get through red tape in less than several decades using Stirling technology built not close enough to run copper wires, but far out in a geologic stable out back, to make hydrogen would solve a lot of problems.

Then you could ride your fuel cell bike all you want!

Alas .. nobody running for politcal office this year has a clue.

They all know we have to use many sources of energy.
But don't know how to do that.

Al Gore knows we need a big infrastructure change.
But doesn't know what.

And there, in the palm of your hand, literally, runs a Stirling engine, the little engine that could, saying

"shine upon me the sun,
warm me with the earth,
let me swim at the surface of the ocean,
and reach into the cold depths,
build me a clean way to burn coal,
use me with natural gas you have so much,
I care not how you warm me,
and I will give you back a clean planet,
raise more food than you can eat,
and let you do things you would not even dream of now"


but all we have to choose from is Tweedle Gee and Tweelde Frum.

Response to electric bike

PostPosted: Wed Aug 27, 2008 8:14 pm
by dholmes7812
Hi Mike! Perhaps one, or a small group of free piston Stirling generators would do the trick? Sunpower Inc. has the EE-80 and EE-80-H generators that are about 100 watt output. I don't know about their size, but 2 of those would get the power output you're looking for. A small campstove propane tank would make a good fuel tank. I don"t know how much Sunpower is asking for their generators, but if you have to ask, you probably can't afford it.

Response to electric bike

PostPosted: Wed Aug 27, 2008 8:25 pm
by dholmes7812
Hey, It's me again. I checked Sunpowers website. The EE-80 is 95 Watts output, 3.7kg (8.1lbs), 193mm long (7.5 inches), and 69mm diameter (2.7 inches) Oh yeah, that would work!

Response to electric bike

PostPosted: Thu Aug 28, 2008 12:37 am
by mike57
Daniel thank you for that idea. If money were no object then two ready to go Sunpower engines as you describe would be excellent, however I'm short of dough recovering from a stroke and really the only way forward is to make my own engines.
looks good as a project I could make from drawings.

Response to electric bike

PostPosted: Sun Dec 28, 2008 11:39 pm
by liftwheeler
I been thinking about the possibilities of building a open cycle hot air engine that could also be driven on pressurized (hot) air to drive a bike. This would allow a small engine with not so much power running in Stirling mode but still give more power on pressurized air mode going up hill.
I have made a small explanation on you tube:
It would require valves though..

Response to electric bike

PostPosted: Mon Dec 29, 2008 8:24 am
by stan.hornbaker
Mike Beadman: Now all you need are the plans. I am not aware of any plans currently available to fulfill your needs.

Jesper Elsander: Very interesting presentation on YouTube. What will you use to provide the heating and cooling of your proposed Hot Air Engine? Remember you have to carry fuel for heating and water or a similar coolant with you. Why not build one and see what it will do?