Bushing consists of two metal sleeves of different diameters arranged on the same axis one inside the other and separated by a layer of elastomer. This is the standard bushing structure. In fact, despite the general working principle, bushings differ from each other. Design features are determined by structure of the unit, where bushings are used and by the estimated loads. The presence or absence of compensation (reverse) holes, offset of metal sleeves, torsional work or stress work – all this make bushings differ from each other.
Despite the diversity of shapes and sizes, bushings will not serve long without one condition, they must be monolithic. If you simply insert the elastomer bushing between two metal sleeves, it quickly becomes corrupted because of the abrasion between the mating surfaces. The solution to this problem is simple. The inner elastomer bushing should be adhered to the metal sleeves. This condition is realized by means of an adhesive layer firmly joining the elastomer to the metal.
The Bushings may contain elastomers that are different in composition. From the traditional rubber to polyurethane. In recent years, polyurethane bushings became increasingly popular. Synthetic polymers successfully compete with rubber in quality of vibration dampening.
Adhesion of polyurethane (PU) with metal parts is firmer than that of rubber (If not specified). Detachment from metal doesn’t occur.