Insulated Bearings for Traction Motors - PPS To prevent electric pitting, NSK developed PPS-resin coating insulated bearings and ceramic coating insulated bearings. Relationship between temperature and insulation resistance of PPS-insulated bearings was assessed. As a result, no deterioration of insulation resistance up to 110° C was observed. Product Features • Isolating Items • Down-sizing • Long life • High reliability • High strenghten cage Condition Description • Electrical leakage • High Accuracy • Vibration • Electric Pitting protection • Proper cage design (DGBB and CRB) • Proper contact point design (CRB) • Traceability • Roughness control of the raceway • Roller and ball surface • Bearing materials are vacuum degassed for high purity • Dimensional stability of bearing steel • Bearings are manufactured to ISO Class 6