Damping and recovery of wheels and castors
Damping capacity is an important element for safe and comfortable transport. It determines not only a low level of vibration, but also noise generation and safe edge traversal.
Hard wheel materials are generally more load-bearing. However, they have the disadvantage that they transmit impact loads, which occur on uneven floors and when traversing edges, to the transport equipment without damping.
Whereas in the past there was a choice between soft solid rubber, medium-soft elastic rubber or hard polyamide, the range has been expanded by wheels with elastomer wheel treads made of polyurethane. Wheels made from these materials achieve high resistance values and high break resistance and offer enormous damping capacity when transporting heavy loads and on poor road surfaces.
Damping through the wheel works as follows: when an impact occurs, the wheel tread deforms and dampens the impact. The softer the wheel, the greater the compression deformation. Soft wheel tyres behave reversibly during running, which means that they return to their original shape during further revolutions without any permanent change. The same applies to the wheel tread after longer deformation during standing and subsequent operation.
The length of time needed to return to the original state depends on the elasticity of the wheel tread. A solid rubber wheel, for example, has very low elasticity; the return deformation therefore takes longer than with thermoplastically processed polyurethane wheels, for example. These wheel treads are highly elastic and have a short recovery time.
Highly elastic wheel treads are also available in the range of cast polyurethanes. In combination with the stable solid aluminium core, these wheel materials provide the best damping capacity with low rolling resistance, high load capacity, high resilience and low wear.
On our product pages you will find an indication of the elasticity of each wheel and the associated recovery behaviour. You will find an overview by material under PU wheels & castors, rubber wheels & castors and polyamide wheels & castors.
The following diagram compares the recovery behaviour of various wheel materials. The curves determined are based on short-term impact loading (60 % of the respective wheel load capacity) under the same conditions with regard to impact load, wheel bearing, wheel diameter and road surface.