Spring life is an important factor to consider when specifying spring products and because they are often vital components within an assembly, Lee Spring offers some tips to help companies to maximise the life of their springs.
Choosing the right spring material is key to a good, long-lasting spring design. Just like you wouldn’t build your house out of cardboard, you wouldn’t use a corrosive spring in a submarine. There are plenty of materials to choose from, including Superalloys, which offer excellent mechanical strength, maintain shape and structure in extreme temperatures and are non-corrosive, for nuclear or offshore industries, or Nimonic alloy for high temperatures.
We all know how bad stress can be for us, but did you know that it’s also the biggest threat to spring health too? While you can’t book your spring into a spa, you can help your springs live a little longer by selecting a larger wire diameter or use with a lower final load to relieve those unwanted high stress levels.
Unless they’re specially made for high temperatures, springs don’t like a lot of heat. High levels of heat can lead to faster coil relaxation or a loss in spring load which will eventually break your perfect springs. Consider temperature controls in the environment to help springs last longer.
Shock loading is when the weight of a load is suddenly increased or sped up, like in the event of a load being dropped from a height. The speed with which a load is dropped onto your springs will increase the weight of the load, resulting in more damage to the spring – much like when you drop something small on your toe from great height –it hurts! Minimising this can save your springs from coil clash, wear, non-axial forces, and dynamic loading, which can all reduce the maximum potential and longevity of the spring.
Shot peening sounds complicated but it’s well worth investing in. Shot peening is the process of cold working with a machine that dimples the surface of the spring, making it stronger and more resistant to that deadly stress we spoke of earlier.
Whilst achieving the right frequency usually sounds like a good thing, with springs it actually isn’t. When a spring’s natural frequency matches that of the frequency of the operating speed, it will resonate, creating a low vibration which can cause the spring to break – a lot like how singing opera at an exact note can smash a glass! To avoid this, keep the operating frequency to no more than one-thirteenth of the spring’s natural frequency.
The act of pre-stressing can help springs to live that little bit longer. Pre-stressing is an additional manufacturing procedure which raises the elastic limit in the torsion, allowing the use of higher solid stresses in your springs – so they’ll be stronger for longer, and far less stressed.
Contact us to find out more about how to get the most out of your springs. Experienced Lee Spring engineers offer expert assistance and technical support to help maximise your spring life.