Under unfavourable conditions the passage of electric current causes damage to raceways and rolling elements as well as degradation of the lubricant. Which, in addition, will result in premature, unexpected failure of a motor or generator. Therefore FAG current-insulating bearings are commonly used in applications where damaging effect of electrical erosion is likely, such as:
Choosing FAG current-insulating bearings for your application will prove to be most cost-effective, considering the repair work and cost of machine downtime and lost production, in case of bearing failure due to electric current passage. To prevent these extra cost it’s recommended to opt for electrically insulated in the planning stage. As a result, you will benefit from reduced maintenance costs and higher machine availability.
The FAG current-insulating bearings can be seen as an upgrade for the standard non-insulated ball bearing with an protection against electric current passage. The specifications are therefore identical to the standard deep groove ball bearing, e.g. the 6219-M-J20AA-C3 FAG has the the same characteristics as the standard 6219-M-C3 FAG.
FAG Current-insulating bearings come in different sizes and variations. The designations are based on the 62.. and 63.. serie. They are usually open on both sides (they have no seals). The current-insulating bearings with a brass cage are available with the suffix ‘M’. Current-insulating bearings are available with an internal clearance of C3 (internal play higher than normal) or C4 (internal play higher than C3).
FAG Current-insulating bearings are marketed by FAG with the suffix ‘J20’. A special coating on the inner or outer ring protects against bearing damage and eventual failure due to the passage of electric current.
The suffixes used by FAG for their current-insulating bearings are: