Anti-vibration mounting is described as an elastic support that reduces
the level of environmental vibration transferral to the machine. This is
achieved by introducing an isolator between the vibrating table and the source
of the disturbance, therefore reducing vibration.
There are three types of anti-vibration mounting – elastomeric, plastic
isolators and metal springs. To select the most appropriate anti vibration
mounting, one must consider various factors such as the level of vibration
produced, the available space to arrange the isolators, the weight the
isolators will support, and the surrounding conditions.
A natural synthetic rubber, an elastomeric isolator can be moulded to
specified shapes and rigidities. This isolator can withstand large deformations
and subsequently return to its original state without suffering any damage. With
its exceptional extendibility and great deformability, it can be used in
Natural rubber elastomers provide better isolation since they offer low
energy dissipation. Their excellent mechanical properties allow them to achieve
stable solutions over time. However, natural rubber deteriorates when exposed
to oils and elevated ambient temperatures. Optimisation of the elastomer mix
increases its resistance to UV rays and ozone.
One of the most expensive elastomers on the market, silicone rubber presents
significantly stable properties and provides effective isolation within a wide
Though they cost less, plastic isolators offer exceptional uniformity. Typically
made from polyethylene and styrene, these isolators have poor mechanical
properties; they have an inferior capacity to resist loads or forces, excessive
creep and permanent deformation. These problems can be resolved with the use of
microcellular polyurethanes. For such elastomers, it is essential that their
load deflection curve be S-shaped, described as a linear section, followed by a
degressive section and then finally a progressive section.
Normally used in applications requiring significant static deflexions, these
isolators are used when it is necessary to achieve very low natural frequencies
and require stability in deflexion over time. However, in order to obtain low
energy dissipation, it is necessary to attach spring systems, which greatly increase
the cost of the solution.
The anti-vibration isolator most frequently used is made from a natural
rubber elastomer, since the devices are capable of withstanding great
deformations and then reverting to their original state practically damage-free.
Anti-vibration mounting featuring rubber-metal parts offers the best
characteristics, as well as the best profits.