wearymicrobe
wearymicrobe Dork
8/27/12 2:53 p.m.

Kind of a odd question does anybody know of a compressed air "motor" in the 5-7hp range being made today of the shelf.

IE I supply the air and I get back 5-6hp of mechanical power.

Also any idea at the RPM they operate at.

kreb
kreb GRM+ Memberand SuperDork
8/27/12 3:06 p.m.

I think that there's a future for this technology. I'm working with a startup that's storing energy generated by windmills during the night in the form of huge compressed air tanks, then releasing the pressure during the days. Smart stuff.

Don't have an answer for your question though.

McTinkerson
McTinkerson New Reader
8/27/12 3:27 p.m.

I could have sworn I read an article about an Indian company who had a bunch of lift trucks & fork lifts that had single cylinder compressed air engines. Now if I could only remember where on earth I read it....it wasn't these guys, however the idea is virtually identical. http://www.engineair.com.au/

erohslc
erohslc HalfDork
8/27/12 4:31 p.m.

I assume that you want positive displacement, rather than a turbine?

Use a small IC motor of sufficient displacement (Briggs&Stratton, or motorcycle) and custom grind a cam to make it effectively a 2 stroke.

Or get a Roots type blower, and, well...., blow it. ;)

Prefer COTS over DIY?:
http://gopro.pro/Gast_Air_Motors.htm
http://www1.mscdirect.com/eCommerce/NavigationServlet/Motion-Control-Fluid-Power/Pneumatics/Air-Actuated-Motors/Air-Actuated-Motors//N-77fto?cm_mmc=Didit--SEM--ItmDtl--PypClk&mkwid=b85nSKOHk&pcrid=1426122523&002=2167518&004=901257762&005=12404319585&006=1426122523&009=b&011=pneumatic%20motor
http://www.grainger.com/Grainger/pneumatic-motors/pneumatics/ecatalog/N-brl
And of course, the default for every search of this type:
http://www.mcmaster.com/?orderview=new#air-motors/=j1akr5

wearymicrobe
wearymicrobe Dork
8/27/12 5:00 p.m.

Actually....

http://www.grainger.com/Grainger/GAST-Air-Motor-6ZC96?Pid=search

Not to bad if I am reading the specs right. Never thought it would be an off the shelf product. That would be very interesting in a small bike.

FYI engineair has been around for years apparently, all they make are unhappy investors not motors.

93gsxturbo
93gsxturbo Dork
8/27/12 7:38 p.m.

14 inch-lbs! I hope thats a typo, otherwise a kitten on a treadmill could make more power.

JoeyM
JoeyM UltimaDork
8/27/12 7:46 p.m.

Guy Negre has been screwing around with air powered cars since the late nineties.

http://en.wikipedia.org/wiki/Motor_Development_International http://guynegre.net/welcome-eng.php

I wrote to him back around 1998 saying that the things he proposed were too anemic for the primary drive train in a US vehicle. I told him to use it as a range extender on an EV. He politely told me that he had no interest in this idea.

benzbaronDaryn
benzbaronDaryn Dork
8/27/12 7:55 p.m.

When I was in school down in Dago, my grandparents neighbor was an cool old german guy. I was talking with this guy and he was telling me about how after the war the germans were very short on fuel and he told me about running a tractor on either wood gasification or thick heavy oil. He said that after running the tractor he'd have to chisel out the muck from the cylinder each day after use.

Needless to say he mentioned a company which used highly compressed air to run a vehicle. Could be interesting technology but you'd really have to store air at very high compression to make it work. All a gas engine is is an air pump afterall.

m4ff3w
m4ff3w GRM+ Memberand UltraDork
8/27/12 8:00 p.m.
93gsxturbo wrote: 14 inch-lbs! I hope thats a typo, otherwise a kitten on a treadmill could make more power.

14 - 114.

83 in-lbs at 100psi/300rpm

egnorant
egnorant Dork
8/27/12 10:15 p.m.

I was playing with a 4 bellows vacuum motor today. Works fine for a player piano, but doubt it has any real power.

Bruce

Wally
Wally GRM+ Memberand UltimaDork
8/27/12 11:31 p.m.

I don't know how much power an air starter motor maks but I know how many noise complaints they can get when you light one up behind an partment building in the middle of the night.

http://www.youtube.com/watch?v=E1RLUxp3Gpo

The0retical
The0retical Reader
8/28/12 12:27 a.m.

In reply to McTinkerson:

http://tech.slashdot.org/story/12/08/26/2351221/tata-intends-to-sell-air-powered-car-in-india

That's where I saw it most recently. Link to source article and the usual pretty helpful /. discussion included.

As a side note Ick pod cars. That is all.

JoeyM
JoeyM UltimaDork
8/28/12 10:03 a.m.

The Tata deal is with MDI (Guy Negre's company.) The wiki entry on the deal is what I linked to above. I still think it is too wimpy for even a city car.....it would make nice "pollution free"* range extender, though.

--
* - no pollution at the tail pipe. It still takes some energy to compress the air. That could be done with really clean energy (e.g. wind electric) or really dirty (e.g. two stroke gasoline)

weedburner
weedburner New Reader
8/28/12 10:14 a.m.

I'd be looking at co2 instead of air...

MadScientistMatt
MadScientistMatt SuperDork
8/28/12 10:29 a.m.
wearymicrobe wrote: Actually.... http://www.grainger.com/Grainger/GAST-Air-Motor-6ZC96?Pid=search Not to bad if I am reading the specs right. Never thought it would be an off the shelf product. That would be very interesting in a small bike. FYI engineair has been around for years apparently, all they make are unhappy investors not motors.

Yep, I was about to check the McMaster catalog when I saw the thread title. Air motors are pretty common industrial automation devices.

dculberson
dculberson SuperDork
8/28/12 2:18 p.m.

I read years ago about a guy that used an air motor to run a car off of liquid nitrogen. In fact it was this car:

http://www.washington.edu/alumni/columns/dec97/car1.html

1997! That's been a while. Wikipedia has an article on liquid nitrogen powered cars.

http://en.wikipedia.org/wiki/Liquid_nitrogen_vehicle

wearymicrobe
wearymicrobe Dork
8/28/12 3:21 p.m.

Just think about something like this. Powered by one. With the instant torque production and light weight attached directly to the rear end might be interesting to try. Trying to find a project of some kind that will keep me occupied and not cost 50K.

Heck I would love to do one with a steam engine if I could.

81cpcamaro
81cpcamaro Reader
8/28/12 8:21 p.m.

Some of the older Diesels used air starters (Like the Mack truck in The Road Warrior), maybe one of those could work, although they are probably well beyond 5 hp, depending on how much pressure you use.

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