Traction motor bearings In most cases, traction motor bearings are configured as follows: Pinion end NU type FAG cylindrical roller bearing Ventilated end deep groove ball bearing or NJ type cylindrical roller bearing with L-shaped angle ring, NUP type cylindrical roller Bearings FAG Insulated Bearings Under unfavorable conditions, motor bearings may be damaged by the passage of current. Even if the manufacturing process of the motor is perfect, the asymmetry of the magnetic force cannot be avoided, and it will cause an induced voltage between the rotor and the stator. In this way, a current loop through the bearing is formed. To avoid this from happening, Schaeffler Group Industrial provides innovative solutions. For example, the inner and outer rings of the bearing are covered with an oxide ceramic coating, or a hybrid bearing using ceramic rolling elements. The withstand voltage of coated insulated bearings depends on the thickness of the coating (100 or 200 μm) and can reach at least 500 V or 1000 V. If a hybrid bearing with ceramic rolling elements is used, the insulation effect will be better. Traction motor insulated bearings for European manufacturers use a plasma spray method to coat the bearing surfaces with oxide ceramics. Oxide ceramic coatings are hard, wear-resistant and have good thermal conductivity. Advantages of insulating coating: Good insulating properties Using special sealing method, J20AA coating can effectively insulate even in wet environment. The outer dimensions of the insulated bearing conform to DIN 616 (ISO 15) standard, so the insulated bearing can be interchanged with the standard bearing. For special occasions, such as the rotation of the outer ring, it is recommended to use a bearing with a J20C coating on the inner ring. For example, the traction motor can be installed with the following bearings: the drive end uses the cylindrical roller bearing FAG NU215-E-TVP2-F1-J20AA-C4 as the non-locating bearing; the non-driving end uses the deep groove ball bearing FAG6215-M-J20AA-C3 as the locating bearing bearing. Suffix description E Enhanced design N Annular groove in outer ring N2 Two positioning grooves in outer ring DA Split inner ring MPA, MP1A, M1A Brass solid cage, outer ring rib guide M, MP, M1 Brass Solid Cage, Guided by Rolling Elements MB Solid Brass Cage, Guided by Inner Ring Ribs Other Design Suffixes are available upon request C3, C4, C5 Radial internal clearance is larger than ordinary group M Body-guided J20AA insulated bearings with an oxide ceramic coating on the outer ring (coating thickness ≈ 200 μm) J20B insulated bearings with an oxide ceramic coating on the outer ring (coating thickness <100 μm) J20C insulated bearings with an inner ring covered with Oxidized ceramic coating (coating thickness ≈ 200 μm) F1 Traction motor cylindrical roller bearing M1 according to DIN43283 standard Brass solid riveted cage, rolling element guided TVP, TVP2 Window type nylon cage Other designs are available on request All configurations are also available with insulated bearing suffix Description E Enhanced design F1 Traction motor bearing M1 Brass solid riveted cage, rolling element guided M Brass solid cage, rolling element guided C3/C4 Radial internal clearance Larger than ordinary group J20A insulated bearing, thicker coating J20B insulated bearing, thin coating T51F American traction motor bearing order example Locating bearing NJ318E.M1.F1.T51F and HJ318E.F1 Non-locating bearing NU328E.M1.F1.T51F Other designs are available on request.