1. Cause of failure (1) Too much or too little grease; (2) The oil quality is not good and contains impurities; (3) Improper fit of the bearing with the journal or end cap (too loose or too tight); (4) The bearing bore is eccentric and rubs against the shaft; (5) The motor end cover or bearing cover is not flattened; (6) The coupling between the motor and the load is not corrected, or the belt is too tight; (7) The bearing clearance is too large or too small; (8) The motor shaft is bent. 2. Troubleshooting (1) Add grease according to regulations (1/3-2/3 of the volume); (2) Replace the clean lubricating grease; (3) Too loose can be repaired with adhesive, too tight to respond to the car, grinding the shaft journal or end cover inner hole to make it suitable; (4) Repair bearing covers and eliminate wiping points; (5) Reassembly; (6) Re-correction, adjustment of belt tension; (7) Replace the new bearing; (8) Correct the motor shaft or replace the rotor.