Lubrication of electric motors aims to reduce friction and internal wear to prevent overheating. The grease serves as a vehicle for the added oil, which effectively does the lubrication functions. The most frequent fault is not the lack of lubrication, but the exaggerated lubrication, made with amount of grease greater than the recommended one. Excessive lubrication causes temperature rise because of the high resistance it provides to the movement of the rotating parts and because of the grease stroke which ultimately loses its lubrication characteristics.
This may cause leakage by penetrating the grease inside the electric motor and being deposited on the coils or other parts of the motor mrosupply skf bearing. The grease used in the motors is polyurea grease mainly developed for electric motor bearings. This grease is well compatible with conventional lithium greases. Grease mixing is not recommended, and if another type of grease is used, consult the manufacturer. For motors with ZZ (armored) type bearings, relubrication is not necessary since they have been factory lubricated for their normal life and use polyurea grease.