Axial Force in a Spring

Posted in: , on 23. Dec. 2008 - 13:00

Dear all

Is the torsional spring will exert any axial force while rotating certain degrees?

(Spring geometry looks a wire in circular geometry with gap in between the adjacent coils)

By giving torque the gap will try to close so there seems to be due to torsional load compressive force will occur in between the coils.

My querey is what is the magnitude of axial force? how to calculate?

Usefuel materials and papers are welcome

Thanks

Prakash ■

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Re: Axial Force In A Spring

Posted on 23. Dec. 2008 - 01:04

Dear Prakash.

Make an isometric sketch and draw the excerted torque force(s) on the coil.

Then make a vectordiagram of those forces and consider the tensions in a cross-section 90 degrees from the introduction of the force.

Then you will see an internal torque appear that pulls the spring together.

Knowing how it works is the solution to the calculation.

In this cases it is always a combination of equilibrium of forces and the law of Hooke.

Success

Teus ■

Teus

Torsion Spring

Posted on 24. Dec. 2008 - 05:13

Thanks Mr.Teus

I will try as ur suggestion to derive the solution

Thanks

prakash ■

Re: Axial Force In A Spring

Posted on 30. Dec. 2008 - 12:45

This is one for Roark (Formulas for Stress & Strain) which is actually coming down in price! As Teus implies, a strain energy examination using a vector diagram will reveal the situation.

A compression/extension coil spring subjects the wire to torsion whereas a torsional coil spring subjects the wire to bending in both the radial and axial aspects.

If you cannot tolerate axial deflection then try a spiral spring(?). ■