The "Little" motor

[Cory]

I have designed a rotary sequence valve that turns two double acting pistons into an inexpensive, powerful, air motor.

Please view my video by searching "little air powered bike"

I am working on my next prototype to see how well this new motor will funtion as a regenerative engine brake, and how far it will go with a 4500 psi tank. Eventually I hope to have products available from air powered bikes, to busses, yard tool, to industrial machines.. Until nothing runs on fossil fuels any more.

I am allowing anyone to use this idea, to create an opportunity for a compressed air powered revolution!

pneubike.com

[tommy]

That is a great project, great video too!

[Uncle Buddy]

Good work Cory, keep it up, stay in touch, post as much info here as you want. I'd love to hear more.

[jjackson123]

I'm so glad you joined the conversation Cory! I've been kind of engineering something like your design for the same ends with similar means as in a solar-air poweRed velocar

[Cory]

Thanks guys.
I am happy to have found some like minded people.

This idea is to be shared with everybody in a free competitive marketplace, to create an opportunity for environmentally friendly technology to gain a huge price advantage over the energy market.

One of my goals is to start the pneumatic racing association, as an international effort to create open source transportation technology..
..anyone want to help with that?

[Uncle Buddy]

You should check out Armando Regusci's engine designs since he has done away with the crankshaft. You should get a lot more speed with constant torque instead of the eggbeater effect of the bicycle crank where the torque varies from 0-100% throughout each stroke.

[Cory]

I am assuming that you have not realized that the Little motor uses two double action pistons, set at a 90° offset, and that the zero point of one piston coincides with the strongest point of the other piston. There is always at least 100% of one piston working at all times, and usually both pistons are pushing or pulling. If I removed one of the pistons, the motor would run as you describe. I have tried it, and it does actually still run, just not with smooth even torque it gets with both pistons working together.

[Uncle Buddy]

What I describe is completely different. I understand what you are saying. The crankshaft--or eggbeater as I call it--has maximum torque when at 90 deg and varying torque through the stroke, as you know. Every child knows instinctively that pushing on the bike pedal at a certain point will get better results. Never mind top and bottom dead center, that's never going away.

The crankshaft substitute uses a rack-and-pinion gear system to transmit all torque 100% at all points of the stroke. I built an air engine like this, called it the torquerack. I once tested it running a compressor, and it got up to 50 psi on the compressor quickly, then I turned it off because my gauge only went up to 50 psi.

See how long you can use an old-fashioned crank style eggbeater before your hand gets tired. About 2 seconds. This is because the crankshaft needs a flywheel. Imagine an eggbeater with a flywheel. Your hand would not get tired. In the case of a car or bike, the flywheel is the weight of the vehicle rolling down the road. And as you say, more than one cylinder.

Armando Regusci does the same thing I did, with chains and sprockets instead of rack and pinion gears. He's built several air powered bikes and cars, and recently got another patent. His doings including a good interview by our member Didier Grimonprez are reported on Didier's website.

There's a video of my torquerack engine on my you tube channel gumpferloofer, a clumsy and clunky homemade engine but it worked great. It could be made as big or small as you want and the gears could be plastic. In fact my pinion gears were nylon or something. I got the rack gear off an old printing press at a junk yard.

Industrial air piston actuators with rack-and-pinion rotation are available when truly smooth 100% torque is needed vs. getting up speed or using a flywheel which isn't always possible. The air engine has maximum torque at 0+ speed so it is kinda backwards to build an air engine that needs a flywheel or equivalent. The rotary actuators are often used for partial rotation but I've seen them say they can make them for 360 degrees also. To keep them from being big and clunky like mine, the piston rod can double as the rack gear.

Put two bikes at the bottom of a hill. One is a 15 speed state of the art bike and the other is a one speed bike with a torquerack crank substitute. I'm sure the torquerack bike will get to the top faster and easier. There are different ways to make a torquerack, I think some designs will allow a variable power stroke, which might be nice on a pedal powered machine.

[Cory]

I understand the principal behind the torquerack, but believe that the little motor has the advantage of lower resistance. If the torquerack was a more effective transfer of energy than why is there no manual bicycles that use the principal? The reason might be that the added mechanisms would increase resistance, or perhaps that the high impact of the end of the stroke would distroy your legs, just like it would distroy an air piston. If you try to compensate with springs or dampers, that displaced energy would have to be factored into the efficiency.

Both pistons in my motor design share the same air supply, and at no point is the flow of air stopped, unless the motor has enough resistance to overwhelm the intake pressure. There is very little change in torque at any point in rotation, and it has full power from a standstill. If you watch my video, there us a point where I demonstrate the motor while I lift the rear wheel, you can see that the acceleration is smooth and even. As one piston heads into the less effective portion of the stroke the other is gaining power. Since they share the same air supply there is an even stream of air supplying even torque throughout the rotation.

Other advantages the Little motor has over a torquerack system include; reduced weigh, easier maintenance, ànd lower production cost.

[Uncle Buddy]

The advantage of the crankshaft is compactness and simplicity. The advantage of the torquerack is 100% torque, objectively based. Your subjective statement that your crank-based engine has no torque problem is OK but torque delivery varies through every cycle of every crankshaft in existence. If you're putting air into your engine at all points of the stroke then the engine is so powerful that the torque variation is unnoticeable subjectively.

I post information about the torquerack so people will know about it and hopefully give it a try. I don't expect you to change your system, it's just conversation and information.

If you are putting air into the engine through the whole stroke, some kind of small compressor could be run too with some of the air you're wasting, in my opinion.

[Uncle Buddy]

Oct 3, 2015 10:22:50 GMT -8 Cory said:

...the high impact of the end of the stroke would distroy your legs, just like it would distroy an air piston.

What impact? Nothing is striking anything at the end of the stroke. Does your air piston strike something?

Did you look at the video of the torquerack? This is very crude, for example the wooden cam is probably slamming against the cam follower wheel or something, which is noisy because the spring on the valve is too strong. I can't imagine an air engine with the piston hitting anything at the end of the stroke. It would self-destruct quickly.

[Uncle Buddy]

Sept 4, 2015 20:24:23 GMT -8 Cory said:

I have designed a rotary sequence valve that turns two double acting pistons into an inexpensive, powerful, air motor.

This valve--rotary vs. reciprocating cam-operated valve--is not easy to do. A lot of people have tried it. If you've made it simple and especially leakproof, that's a big step.

If you can make it adjustable so the engine can run efficiently at cruising loads, without making it complicated, then so much the better. I'm sure it's been done but sealing is always the problem.

I'm glad you're using pistons. That means it can be built with off-the-shelf parts. For example, they could buy the valve unit and other special parts in a kit, with a manual, and the piston actuators could be bought from any industrial supply.

[newt]

This patent US2008202116 (A1) is probably not worth reading.
worldwide.espacenet.com/publicationDetails/biblio?FT=D&date=20090115&DB=worldwide.espacenet.com&locale=en_EP&CC=AT&NR=417996T&KC=T&ND=4

It reads to me like a bit of a spoiler for anyone who wants to put a cut-off or control valve between a high pressure reservoir and an expander. However I thought you might be interested Cory. Unc is right - try to incorporate some kind of adjustable cut-off valve for efficiency.

Good work!

Newt

[Cory]

I just spent the last couple of days crowd sourcing research funds with a pocket full of custom patches. 

[Cory]

I am getting very close to assembling my next prototype, which is focused on beingable to regenerate compressed air using the motor as a brake. Most of the parts are ready, but I still need a few valves and fitting, and some tires and tubes. If you are able to help at all, please send me a message, I can reward contributions with one of my brand new patches, with more detail than the first series. I hope to exchange enough patches this week to be able to order the rest of the parts needed build the next bike.