Torque Potential with Constant Force Springs?

"What torque could a chained array of custom constant force springs absorb and is there a loss in winding and unwinding or mechanical gain?"

The laws of physics still apply. Give it up. This reeks of perpetual motion...........

Have a nice day. _{(Del made me say that)}

I have an application in mind that uses my heavier torque input and runs it as higher rpm to match an overspeed addition to my electric bikes top speed. Is that ok with you? :)

Regen braking in a hydraulic/diesel hybrid is effectively storage of energy in an air spring (typically the compressed nitrogen in an hydraulic accumulator). This air spring could be used for peak averaging as well, (thereby keeping the diesel operating close to its efficiency peak most of the time) except the amount of energy stored is too small to be useful. Mechanical springs would be the obvious, simple hybridizing method, but simply cannot store meaningful amounts of energy -- they are far worse even than hydraulics.

Start by doing the math.

Springs are great in their lack of hysteresis -- in other words, they return practically all the energy that goes into compressing them. Unfortunately, their energy storage vs weight ratio is rotten. Those windup keys you used to see on the back of early VW beetles were not real.

Hello BJ,

This application sound good, now you have explained it a little more. Good luck with trying and keep in touch please?

Take care

Interesting question, you could wind a spring at varying tensions, but they would only be held if there was sufficient friction to stop the tension evening itself out.
Of course the friction would be the enemy of efficiency.

There are mechanisms to give changed gearing or constant force. Google 'fusee'.
Years ago we made rubber powered dragsters, the rubber cord was wound around the back axle, to give a power boost as the rubber un-wound and became less taut we wound the first turns onto a bigger diameter section of axle, and the final (high tension) turns onto the narrowest diameter part. This avoided wheel spin at the start.
Del

Hello Brett,

Is there any chance you can shed some light on why you want to set this, seemingly difficult to impossible 'thing' up? Are you making a gun?

I would be obliged if you could reply please as we may............... Just may be able to sort something out.

Take care.

Here's help for you! http://search.globalspec.com/ProductFinder/FindProducts?query=constant%20force%20springs

or try; http://en.wikipedia.org/wiki/Constant-force_spring

Perhaps if I asked "what book takes an in depth view of constant force spring mechanics?"; but I didn't think this was a book club!

Thanks everyone for trying!

Hello BJ,

CR4 may not be a 'book club' per se, but anything which gives details and info' for whatever use is open to all, and it may be a small Manual or book is of more use 'in the field'?

Take care my friend