Electrically insulated bearings

Bearing manufacturer NKE offers electrically insulated rolling bearings in standard sizes and in different design variations. Electrically insulated bearings provide optimal protection against bearing damage caused by electro corrosion.

For modern electrical machines, 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.

Electrically insulated rolling bearings are integrated with an efficient electrical insulation that prevents the passage of electric currents through the bearings. Besides saving costs, this means an increase in reliability and service life of the machines.

NKE offers electrically insulated rolling bearings in standard sizes with outer ring diameters between 80 and 400 mm. Special sizes are available on request. The bearings are available in different design variations. Bearings with an oxide ceramic insulating layer have a guaranteed minimum breakdown voltage of 1000 VAC or DC. The insulation coating is applied to the outer rings by a plasma spraying method. For smaller bearings, rolling elements made of oxide ceramic (silicon nitride) can be used. The load ratings, boundary dimensions and tolerances of NKE electrically insulated bearings are identical to those of standard bearings and therefore completely interchangeable with conventional bearings. Electrically insulated bearings provide optimal protection against bearing damage caused by electro corrosion and therefore enable significantly improved reliability of electrical machines compared to conventional bearings.