Cylindrical wound torsion springs are used for axial loads,i.e. a circular movement. When loaded, the wire is exposed to a deflection. Normally, the inside body diameter is mounted on a shaft or similar. Mounting must be carried out in such a way that there is always play between the inner diameter and the shaft. See examples in the tables below.The load must be applied in such a way that the torque application binds the spring (see figure), as it is strongest in this direction. To minimise the friction agains the shaft, use of fixed tension ends is preferable.

Torsion springs have a linear spring characteristic, i. e. if a spring is turned 10° to provide torque of 1 Nmm, the same spring will provide a torque of 2 Nmm at 20° torsion.

Torque

Torque is equal to force x leg length:

M= F x A.The closer to the end of the leg the load is applied, the less counter force is created. The following tables specify torque in Nmm, i.e. the force obtained on the leg 1 mm from the centre.

Permitted load, life

If the maximum torque angle (p) as specified in the fol-lowing tables is used,a maximum of 10000 load cycles is permitted. If only 80% of the permitted torque angle is used, the lifespan of the spring increases to 200000–400 000 load oscillations. If only 70% of the permitted torque angle is being used, an almost infinite lifespan can be expected.