Let's Build a Hybrid Cycle

[belovelife]

Originally Posted by alexander

oooh, ooh how about a compressed air motor and drive system, like in the european compressed air cars.

Start with mounting a , 4500psi carbon fiber air tank
then the fun of designing an ultra small, rotary compressed air motor, that will be small enough to fit in the wheel, but still spin fast enough to be able to, when geared down, drive you with some, perhaps fairly significant speed (at 4500psi, you dont need a hell of a lot of air to drive it) by the way (www.engineair.com.au for motor design ideas)

this way you fill the tank with compressed air, it makes no electro-magnetic pollution, it makes no noise, until you push the throttle, which will open up a pressure valve it up and propell you forward



juust another thought and since the motor will have to be mounted on the forks, you really dont have to worry about air line getting twisted, as long as it runs with the forks and has some play in it, it should not effect your steering

Juust another idea

(although the effieciency of use of the compressed air would be inquestion using this tool below)
could you just use on of the pnumatic air tools meant for heavy machenery (ie diesel)
the hook up a worm drive to the tool so you have the tool in line with the frame
and the pnumatic connected to a worm gear the that drives the tire
or get the air tool already focused at a 90deg angle

then you wouldn't have centripital values to worry about
you could just get the air tool from any auto store
and the tank
well you could get one of those carbon fiber tanks that are light and are capable of storing like 20,000 lbs/sqin of hydrogen

[alexander]

Oh please, how much more fun is it to design and build a rotary engine yourself, versus hacking up a perfectly fine air tool. Also with a rotary engine, there is nearly any vibration, if any at all, it's not your typical piston air engine...

[DFINITLYDISTRUBD]

Originally Posted by alexander

Oh please, how much more fun is it to design and build a rotary engine yourself, versus hacking up a perfectly fine air tool. Also with a rotary engine, there is nearly any vibration, if any at all, it's not your typical piston air engine...

Besides the fact that most air tools are EXTREMELY inefficient Bear in mind that an air powered die grinder which has at best the same power as a Dremmel tool or a cheapy drill motor requires a minimum of a 1hp motor driven compressor just to run it in short bursts. So wastefull.... Much better to design your own.

(at 4500psi, you dont need a hell of a lot of air to drive it)

It may not seem like much but 4CFM at 4500psi is a hell of a lot more than 4CFM at say 10psi...



(course I fixed that problem here, my die grinder has a 48cc trimmer engine)

[belovelife]

good point, its just the whole milling of the block that hinders that

but you could take the design of the air tool and make it more efficient
or you could just get the air tool and make the inner componets more accurate
in dimention to make it more efficient

i just thought that if money was a factor, then the air tool would be the cheap way to go
not as efficient
but readily availible

[DFINITLYDISTRUBD]

The primary issue is getting an ideal seal without increasing friction and wear to levels which negate any gain...the problem with typical air tool motors is that they leak pressure like a sieve (blow-by) until they get enough [B]pressure[/B] and volume to operate typically 5 to 9CFM @90+psi.....and even then under load they leak and waste power.

[belovelife]

is that a fundimental flaw in the desighn, or a desighn aspect needed for the tool?

[DFINITLYDISTRUBD]

Originally Posted by belovelife

is that a fundimental flaw in the desighn, or a desighn aspect needed for the tool?

A fundamental flaw of design, primarily for profit yield, secondarily because the fellers that came up with the design for whatever reason decided it was good enough long before giving it enough thought to catch the errors of their ways.

It really is a good foundation for an air motor design but serious rethought need be applied to how the slides (pistons) and rotor seal to each other and the housing, also the inlet and exhaust port flow should be parallel to the rotation of the motor rather than the oddball perpendicular layout found in many tools or the paralel in perpendicular out flow.


Of course a liquid refrigerant powered rotary which uses atmospheric heat to convert it to a gas and then an electric compressor to squish it back to a liquid would be super cool....use the evap. to cool the refrigerant holding tank so the compressor don't have to work so hard and use the condenser to heat the rotary....while ye rat it use the heat from the alternater and compressor motor to provide more heat to the evap. side....yah .....won't run forever but prolly a lot longer than compressed air and at much lower pressures....I call it the atmospheric heat steam engine (the steam being R134A or similar in gass form)

[belovelife]

i know for efficient transfer of liquid oxygen to gas
it is more efficient to use a coil of tubing, for my purpose we get more efficiency
in gas form than liquid because you have more efficient combustion and less waste oxygen
the liquid form has too high of a concentration of oxygen vs fuel

now in theory, atmoshere could be condensed to a liquid, but all the gasses are liquid at different
pressure and temp (STP)
and if you compress atmoshere in any form you get water
which if you use a compressor in any job you know you have to bleed the water out of the
tanks

but you could use the transfer of heat from the friction of the pnumatic motor to give a little extra
force to the compressed air right

anyway this is getting way off topic

but do you think if you had a pnumatic tool
and you took it apart
that you could fabricate the inner parts to closer tolerances
so you could use the same block, just machine it to have more accurate tolerances?

[DFINITLYDISTRUBD]

Absolutely, and not....the problem is sloppy fit and no seals for the rotor itself....you can machine in space for rotor seals but there really isn't anything you can do for the sloppy fit of the sliders particularly once they start wearing....which without an inline oiler or periodic oiling will wear very fast....as a welder I primarily use electric tools because of this...you don't want your grinder spitting oil residue all over the parts your in the process of cleaning.

[belovelife]

so you couldn't build a return valve that has two outputs
air and oil
where the oil returns to the cylinder with one way flow valves
and the output of air is filtered for this process?