Development of a ceramic antifriction bearing

A high quality rolling bearing of silicon nitride was developed by improving the reliability of materials and through numerous experiments on bearing applications. The high strength silicon nitride ceramics for the bearing were developed by the use of sintering additives of yttria and alumina and newly synthesized high α–phase silicon nitride powder of uniform particle size and shape. The developed silicon nitride bearing was evaluated by rolling fatigue test in comparison with various other ceramics and high–carbon chromium steel. The result showed that silicon nitride had the best quality. Moreover, the applicabilites for high–speed bearings, all–ceramic bearings and dry–lubrication bearings were clearly recognized.