rolling bearings

For modern electrical machines with high degrees of performance, and demanding reliability and service life, equipment failures by electro corrosion can cause significant problems. Under unfavourable operating conditions, bearings in electrical machines can be damaged by the passage of electrical currents. Such a passage of current can be caused by faulty or damaged insulation of the bearing shields or an ineffective earth connection of the machine.

The appearance and the degree of electrical damage of bearings depend on the individual operating conditions, e.g. the actual effective voltage. The machinery user may notice this process only by symptoms, such as increased running noise or vibrations, until the bearing fails prematurely. The appearance of the damage may vary from visually detectable single craters and to fluting with discolorations around the Slewing rings affected areas.