Demand for non-ferrous bearings has been steadily rising in reciprocating and some rotating applications, replacing more traditional offerings. To obtain the optimum life from any seal, the guidance of the sealing surfaces is critical. As a result, non-metallic polyester bearing materials have been developed.
Polyester bearings have the advantage of being non galling and sacrificial. The bearing wears rather than the mating shaft or cylinder, saving costly replacement of the mating parts. The removal of galling from a reciprocating system also tends to reduce the chance of seal damage, while polyester bearings are also easier and cheaper to change when worn.
Polyester bearings can be moulded or turned, and are usually supplied in a split form for reciprocating applications such as hydraulic cylinders. They are typically more heavy duty than PTFE.