Metal fatigue typically occurs when materials have been exposed to repeated stress or strain, such as from intense pressure or vibration.
If left unchecked for long enough, this may cause structural components (including welds securing them) to weaken or even break down entirely, posing safety and downtime risks.
“The risks are probably greatest on materials handling machinery that rely on vibrating screens and conveyors to sift, sort and transport materials, in uses such as food and beverage progressing, construction materials including aggregates, and widespread mineral processing applications,” says engineer Vinh Lam.
“Vibration can particularly affect machinery such as isolating screens, mixers, motors, compressors, crushers, blowers and bins,” says Vinh, who has more than 20 years of experience in industrial actuation, isolation, and suspension and is Technical Product manager at Air Springs Supply Pty Ltd.
Air Springs Supply is national distributor of Firestone Industrial products, which offers a highly effective and maintenance-free solution to excessive noise, harshness, and vibration (NVH) through compact and highly efficient Marsh Mellow® isolators.
Firestone’s globally proven Marsh Mellow springs are engineered for immense strength and longevity with a hollow centre surrounded by a solid rubber core and fabric ply-reinforced body to deliver constant vibration isolation with changing loads.
Their unique construction delivers low natural spring frequencies to provide excellent isolation of forced frequencies in the range of 13-20-HZ (800-1200 cycles a minute).
This outstanding performance – and a maximum load range extending from 1.4 kN up to 88 kN (on special order) – makes them particularly suitable for vibration isolation applications, says Vinh.
“Marsh Mellows also make ideal shock absorbers for conveyor and primary product and other materials handling applications, particularly in situations where their corrosion-resistant durability means they will survive damp and corrosive environments in which standard coil springs may fail,” he says.
They have no moving parts and require no maintenance or lubrication, so they are ideal for applications in grimy and demanding environments. And because they reduce structurally transmitted noise caused by vibration, Marsh Mellows have considerable OHS and comfort benefits by being quiet in operation.
They also eliminate problems such as coil springs cracking to allow fragments of metal to damage equipment. Additionally, Marsh Mellow springs exhibit exceptionally high overload characteristics and offer some support even during failure.
The springs’ components (rubber, bias plies, engineered size of centre space) are combined in different ways to meet specific load and performance requirements.
Naturally different types of springs have different performance characteristics suited to particular tasks. These should always be discussed with suppliers who have wide experience in the particular area of application being considered.