Current insulated roller bearings

The power densities of modern, converter-fed three-phase drives are often the source of damage to roller bearings through spark or electro-corrosion. Such damage occurs, for example, when a high-frequency current with a high voltage gradient flows through the rolling elements and contact areas.

The electrical discharge causes the material to heat up and even melt at the surface. This can lead to considerable damage to the raceways, in the worst case complete failure of the bearing can occur. Visible signs for such damage are melting craters, particle break-out and discoloured lubricants.

However, this damage can be avoided easily and elegantly by using current insulated roller bearings.

Insulation is in the form of a ceramic layer at the outer race, and ceramic rolling elements (hybrid bearings) can also be used. Current insulated bearings have the same dimensions as standard bearings, which means they can also be retrofitted in exchange for these.