Following these guidelines will not only keep your machines running evenly by minimising the equipment’s internal stresses, it will also help maximise the service life of springs without compromising the health of the machine. The life of a set of springs is that of the one most stressed. Keeping the spring heights consistent means stresses in the springs will also be consistent. That means a longer service life.

As well as selling various components for screens and feeders, including different types of springs, businesses also offer the service of testing vibrating equipment to identify adverse motion, from an equipment longevity perspective, and ways to improve performance. When a machine is running unevenly, we need to look for the various causes.

If the springs are in good condition and their static heights are reasonably similar from one side to the other, it becomes easier to identify the cause of the adverse motion. If the springs are in poor condition and/or vary significantly in height (left to right), it can often mean an additional site visit is required before there can be recommendations to correct the unit’s motion. This adds to the service and means the machine will run poorly for a longer period.

The three most common (but not the only) types of springs seen on sites, on vibrating screens and feeders, are steel coil springs, rubber springs and screen (or oscillating) mounts. Although they differ in their construction, they all perform the same function on vibrating equipment, and their behaviour is governed by their deflection from their free height when under the weight of the machines they support. In all cases, the laden height of the spring is simply the vertical distance between the surface of the mounting bracket sitting on top of the spring and the surface on which the spring is sitting.

The design intent for vibrating machines is for them to wear out after many years of reliable service, rather than fall apart due to fatigue. In many situations, regular consideration of screen and feeder support springs in a site’s maintenance checks will make the difference between years of reliable service and premature failure.

Once a vibrating screen or feeder is running well, which is how every machine should start life, the most likely cause for it to run poorly is the adverse effects of changes in the support springs.