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Scaling pullback motors for mechanical storage

Scaling pullback motors for mechanical storage

(OP)
Hello everyone,

I've just joined this forum, as I'm currently located in Fiji, where I work primarily in the energy sector on sustainable energy & transport issues. I've been assisting Pacific Island Countries in providing a variety of options to help reduce reliance on imported fossil fuels, and this has involved coming up with regionally appropriate solutions which can be introduced and disseminated.

On that note, I’ve seen this great flywheel prototype by Maxwell Von Stein from Cooper Union in New York City, and I think it’s a step in the right direction toward incorporating mechanical storage for transport and reducing hazardous waste variables battery systems create:
https://www.youtube.com/watch?v=-knIZj-Z0Zs
http://isindexing.com/isi/papers/1415604992.pdf
http://www.gizmag.com/flywheel-bicycle-regenerative-braking/19532/
https://www.youtube.com/watch?v=BOnjtEKArXk


However, I've been particularly interested in pullback motor systems, particularly the Darda Stop n Go system, both for application in bicycle drive trains, and supplemental pedal-powered storage for marine applications (which can be utilized on sailboats in the event of wind dying down.)
Pullback Toy Motor Dissection
Hobie Mirage Drive

If anyone has experience with developing mechanical storage systems of this nature, I'd be very interested in corresponding further. I've discussed it with the Mechanical Engineering Department at the University of the South Pacific, but no one has the specific engineering background or experience to contribute much to an appropriately scaled design. I look forward to input from the forum.

Thanks,
Andrew

RE: Scaling pullback motors for mechanical storage

This is a good post. The links are very interesting. I suppose that no one has replied because mechanical energy storage is hard, especially for mobile applications, and the number of investigators is low. I cannot offer anything other than encouragement.

Although the MM Malkovitch gearbox in the first youtube video does not store energy, it is a worth a look. The inventor is using a load-balancing mechanism for the planets. This mechanism was invented by Felix Fritsch of Simmering-Graz-Pauker, a Viennese gear manufacturer, probably in the early 1960s. Nick Chironis wrote about it in "Gear Design and Application [1967]". It was not a commercial success. I have never seen it used anywhere else. From comments on the video, Malkovitch achieves the speed variation with a brake. This is a fatal flaw, because it wastes energy. He dissolved his company recently.

The Hobie Mirage Drive does not store energy either, but it is a great invention.

I wonder why Maxwell von Stein's flywheel bicycle has not appeared on the market. Maybe it is the expense. He is using the Nuvinci variable speed gearbox in addition to a flywheel and extra gear and chain. These devices also increase the weight. The heavy flywheel is high on the frame, which would adversely affect the handling.

Thanks to Andrew for providing this information.

RE: Scaling pullback motors for mechanical storage

I wonder why Maxwell von Stein's flywheel bicycle has not appeared on the market. Maybe it is the expense. He is using the Nuvinci variable speed gearbox in addition to a flywheel and extra gear and chain. These devices also increase the weight. The heavy flywheel is high on the frame, which would adversely affect the handling.
Using an off-the-shelf hub motor, controller and Lithium battery would be cheaper and offer much higher energy density.

je suis charlie

RE: Scaling pullback motors for mechanical storage

If it must be a battery, I think it should be a lead battery instead, as it would accept frequent load and partial unload cycles as its standard working mode.
However, a capacitor bank looks to be a much better solution here.

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