Development in Lead Free Polymer Based Bearing for Automotive Parts

The bearing is used for the sliding part of automotive parts, for example the brake pedal and the seat. As many of these bearings are aimed for maintenance free, the polymer based bearing that can be used under no lubrication is applied. This bearing material has three layer structures consisting of steel-backing and a porous copper alloy interlayer impregnated and covered with the polymer composite, which consists of poly-tetrafluoroethylene (PTFE), lead and others (1), (2). Lead has the characteristic to form the transferred film of PTFE to the countershaft, and this phenomenon improves the wear resistance. This bearing material shows the excellent bearing performance by the characteristic of lead under no lubrication. However, because lead has been designated as one of the environmental pollutants, the addition to the bearing material is being restricted in recent years. Therefore, lead free polymer based bearing that can be used under no lubrication was developed in this study.