Storing energy in a torsion spring

[alex1978]

Hello!

This might be a seriously obvious question but...

if I were to wind up a torsion spring, such as the type found in a clock movement, and then not release it, how long could that energy stay stored? Presumably it depends on the material used but could it hold it's energy for years?!

Many thanks,
Alex

 

[UltrafastPED]

Yes; they will stay wound for a very long time ... as long as the clock isn't ticking.

I have an 8 day clock with a torsion spring - bought by my great grandfather in 1879. It worked well when I repaired it in 1965. I could stop/start the movement by moving a pawl on/off one of the gears; this was handy in making adjustments. When I would get back to work on it hours/days/weeks later the spring would not have lost any torsion.

However, it dead break when over-wound. It sat for many years until I gave it to my son the mechanical engineer; he repaired the spring (welded it? I forget) and it is still ticking away whenever he winds it up.

 

[alex1978]

Brilliant - thank you. I thought that was probably the case. Good to hear a real world example!