Traction motor bearings In most cases, traction motor bearings are configured as follows: Pinion end NU cylindrical roller bearing ventilated deep groove ball bearing or NJ cylindrical roller bearing plus L-shaped angle ring, NUP cylindrical roller bearing Insulated bearings under adverse conditions, motor bearings may be damaged due to the passage of current. Even if the manufacturing process of the motor is perfect, the magnetic asymmetry is unavoidable, it will cause induced voltage between the rotor and the stator. In this way, a current loop through the bearing is formed. In order to avoid the occurrence of the above situation, the Schaeffler Group Industrial Division provides innovative solutions. For example, the inner and outer rings of the bearing are covered with oxide ceramic coatings, or hybrid bearings with 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 500V or 1000V. If a hybrid bearing with ceramic rolling elements is used, the insulation effect will be better. Insulated bearings for traction motors for European manufacturers use plasma spraying to coat the surface of the bearings with oxide ceramics. The oxide ceramic coating is hard, wear-resistant and has good thermal conductivity. Advantages of insulation coating: Good insulation performance. A special sealing method is adopted, and the J20AA coating can effectively insulate even in a humid environment. The outer dimensions of insulated bearings conform to DIN 616 (ISO 15) standards, so insulated bearings can be interchanged with standard bearings. For special occasions, such as outer ring rotation, it is recommended to use bearings with J20C coating on the inner ring. For example, the traction motor can be installed with the following bearings: cylindrical roller bearing NU215-E-TVP2-F1-J20AA-C4 is used as a non-locating bearing at the driving end; deep groove ball bearing 6215-M-J20AA-C3 is used as a locating bearing at the non-driving end . Suffix description E Enhanced design N outer ring with annular groove N2 outer ring with two positioning grooves DA split inner ring MPA, MP1A, M1A brass solid cage, outer ring rib guide M, MP, M1 brass Solid cage, rolling element guide MB solid brass cage, inner ring rib guide If required, other design suffixes can be provided C3, C4, C5 The radial internal clearance is greater than the ordinary group M brass solid cage, rolling Body-guided J20AA insulated bearing, the outer ring is covered with an oxide ceramic coating (coating thickness ≈200 μm) J20B insulated bearing, the outer ring is covered with an oxide ceramic coating (coating thickness <100 μm) J20C insulated bearing, the inner ring is covered with Oxidized ceramic coating (coating thickness ≈200 μm) F1 Traction motor cylindrical roller bearing M1 compliant with DIN43283 standard brass solid riveted cage, rolling element guide TVP, TVP2 window type nylon cage If required, other designs can be provided All configurations can also use insulated bearing suffix description E Enhanced design F1 Traction motor bearing M1 compliant with DIN43283 standard brass solid riveted cage, rolling element guided M brass solid cage, rolling element guided C3/C4 radial internal clearance Larger than ordinary J20A insulated bearings, thicker coating J20B insulated bearings, thinner coating T51F American traction motor bearing ordering example locating bearings NJ318E.M1.F1.T51F and HJ318E.F1 non-locating bearings NU328E.M1.F1.T51F If required, other designs can be provided.