NVH isolators so efficient they can be used under hospital operating tables or beneath laser display platforms and theatre spotlights are turning their talents to new industrial uses.
Firestone Airmount® pneumatic bellows actuators have long been known as an ultimate isolator for noise, vibration, and harshness (NVH) sources, such as compressors, conveyors, packers, vibrating screens, motors, pumps and other rumbunctious industrial paraphernalia.
But now these proven performers – which have been demonstrated in service for years to achieve NVH isolations sometimes exceeding 99 per cent – are attracting interest for high-tech applications such as R&D laboratory equipment, aerospace and defence guidance systems, and in high-density hyperscale data centres proliferating in Australia with the impact of AI and automation on industry.
“Ultimate NVH prevention and insulation is now critical in sectors where lightweighting or high-frequency acoustics create unique challenges,” says Vinh Lam, Technical Product Manager and a leading pneumatic technology specialist at Air Springs Supply Pty Ltd, which is Australian distributor for Firestone Airmount isolator and Airstroke® actuators.
Airmount isolators are, in effect, tremendously tough, highly engineered balloons identical in construction to the rugged air springs used in the suspension of semi-trailers, luxury coaches, trains and all-terrain vehicles. Airmounts are the only passive isolator that operates on the principle of compressing a gas rather than deflecting a solid. Because of this, Airmounts are the passive isolator with the lowest natural frequency (and the lower the frequency, the better the isolation effectiveness).
“Data centre technology isolation is emerging as a compelling need, as transformational investment is occurring here. In the past year, for example, Microsoft has announced $A25b will go into Australian data centres, while Amazon Web Services has committed another $A20b. In addition to stand-alone data centres, intensive processing industries such as food, beverage and high-tech manufacturing have greater need than ever to limit NVH in their own data storage and automation operations,” says Vinh, who provides engineering insights, expert troubleshooting relating to particular industries and applications. With data centres, for example he notes issues such as:
- Hardware Protection: High-density computing infrastructure, storage systems, and networking equipment are highly sensitive to vibration and structural movement. Thus, isolating servers from the vibrations of heavy machinery (like chillers and pumps) curtails read/write errors, hardware degradation, and premature drive failure. Isolating HVAC centres can be particularly important also, to ensure reliability and guard against metal fatigue in critical plant such as banks of fans or closed loop direct-to-chip (D2C) cooling systems used to radically reduce water and energy use.
- Community and workforce well-being: Data centres (and many other automated industries) operate 24/7 and generate significant low-frequency noise (infrasound and deep humming) that travels long distances. Low frequency sound can also forcefully penetrate the inner ear, bypassing traditional earplugs and exposing workers to hearing issues. Isolating this noise at the source protects nearby residents from sleep deprivation, vertigo, and chronic stress caused by persistent noise pollution.
Vinh says eliminating NVH is critical also in lightweighting industrial equipment, such as in automation applications, because removing mass inherently reduces a structure’s stiffness and natural damping capabilities. Without proper NVH management, lightweighted equipment may become highly susceptible to severe structural resonance, accelerated fatigue, and acoustic failure.
“This need to protect against NVH transmission applies whether users mount the source of the NVH on isolators to prevent it transmitting problems to nearby equipment (a stamping press, motor, or compressor, for example) or where a sensitive piece of equipment is being mounted on isolators to remove it from surrounding NVH (such as sensitive control systems, instrumentation, laboratories, or entire computer rooms).
Airmounts can be used both as passive (permanently sealed) isolators, or as active isolators, being fed higher or lower pressures by compressors in response to changing load or conditions.
By using Airmounts in capacities from a few hundred kilograms to tens of thousands, severe occupational health and safety issues have been overcome through isolation efficiencies of 90-99 per cent.
Airmounts are so effective they are used beneath some hospital operating beds and to support weapons guidance systems. As well, in Australia, they are used beneath theatre light systems required to project steady beams onto distant stages.