Designing wave springs: your questions answered

Author : Simon Ward, TFC

10 May 2021

The Juno space probe uses over 60 different springs to perform three major functions: to open the doors to the solar panels, to guarantee the doors remain latched during flight, and to position the arms it uses to measure Jupiter’s structure. Of course, it’s not just in space probes where projects require springs with very specific requirements. Here, Simon Ward, Technical Manager at TFC, answers some questions about designing wave springs.

What is a wave spring?

An alternative to the traditional coil spring, wave springs are produced from pre-hardened flat wire and formed to a precise diameter with a sinusoidal waveform. When loaded, this means that they can act like a spring by deflecting and providing a preload between two surfaces. Therefore, wave springs can be used to preload seals or bearings, absorb shock, and compensate for dimensional variations and thermal tolerances.

How are wave springs manufactured?

Wave springs are manufactured by coiling flat wire on edge, known as ‘edge winding’. This process increases design flexibility and reduces the lead time for bespoke designs. It also ensures that prototype batches are manufactured in the same way as production parts, so any prototype or preproduction testing can be considered valuable production data.

With edge winding, only the required flat wire material is coiled, eliminating material waste. The circular-grain metallurgy also improves strength, and the cold rolling process causes metal grains to elongate and lock together, which provides good mechanical properties.

TFC’s engineers also use a ‘No-Tooling-Cost’ process, which reduces production times and allows any modifications, at the prototype stage, to be made quickly and easily. Therefore, this process can help provide an economical custom option in weeks, not months.