This type of failure mode, also known as electrical erosion failure, is a very common form of bearing failure.
While ball bearings themselves are non-conductive and do not generate electric current, excessive external current can cause electrical erosion spots, pitting, and melt craters to appear on the surfaces of the raceways and balls. Consequently, the bearing will exhibit elevated noise and vibration levels, ultimately leading to a complete seizure and failure.
Excessive current causes many zigzag discharge marks on the inner ring and ball of the deepening ball bearing
To prevent electrical erosion failure caused by excessive current, the following measures may be considered:
1. Ensure that the grounding system is installed correctly.
2. Use insulated bearings (either insulated bearings or hybrid ceramic ball bearings).
3. Use industrial-grade plastic bearings.
