Wear measurements of self-lubricating bearing materials in small oscillatory movement

During last decades the interest in self-lubricating materials was increased because of ecological reasons. An example is the tendency to replace grease-lubricated bearings with self-lubricated ones in guide vanes of water turbines. However, in some cases, greaseless materials did not meet durability requirements. In order to explain operation of greaseless bearings in this particular application, a research program was carried out. Tests performed in the power plants let the authors determine the operating conditions of guide vane bearings. A special testing device was designed and built at Gdansk University of Technology to measure wear rate of self-lubricating materials in conditions of high loads and small oscillatory movement, which turned out to be dominant component of movements in guide vane bearings. Evaluated wear rates differ much from wear rates evaluated for unidirectional movement.