Torsion springs work by torsion or twisting. As the spring is twisted it applies a resistive torque. This torque increases at a linear rate. torsion springs should always be designed so that the force or torque causes the spring to tighten. (i.e. if the torsion or twisting action is in a clockwise direction the spring should be anti-clockwise or left-hand wound.) They can be used in the other direction but the operating stresses are likely to cause problems.
Torsion springs can have an endless number of leg designs. These fall into the three categories of tangential legs, radial legs and axial legs. In addition, torsion springs can be single (with one coiled body) or double (with the two helical bodies connected by a central leg) and can be closed on open coiled.
Torsion springs have a wide range of uses and are normally used over a mandrel. John Binns & Son supplies small torsion springs for uses such as in electrical equipment and hinges as well as larger torsion springs for uses such as in agricultural equipment.
John Binns & Son has a great deal of experience and expertise in the design and manufacture of torsion springs and always welcomes the opportunity to help customers obtain the best possible solution for their product. Given the complexities of torsion springs, we would recommend that designs are checked.
The following parameters are important in establishing the correct design of torsion spring:
- The size of any mandrel over which the spring is to work. As a torsion spring deflects, its
- inside diameter reduces and failures are likely if the spring begins to grip the mandrel.
- The size of any hole in which the spring fits.
- The lateral space available. As a torsion spring deflects it increases in length and failures are likely if this growth cannot be accommodated in the application.
- The torques/forces required and the rotation at which they are required
- The maximum working deflection required
- The frequency of operation
- The operating environment. This will determine the choice of material and/or the choice of any finish for corrosion protection.
- How and where the spring is to be fitted. This will determine type of ends required.