Bearing protection ring
The Current Diverter Ring provides a bearing protection device for motors using VFDs to adjust the speed output of ac motors. The motor manufacturers can conveniently package the motor, drive and CDR. VFD-controlled motors inherently produce destructive shaft currents that must be redirected around the bearings; otherwise, unmitigated electrical currents initiated by the VFD and induced by the motor shaft destroy the bearings.
Inpro/Seal , www.inpro-seal.com