1. Serious wear and tear of the shaft.
2. Serious wear of shaft sleeve.
3. The driving magnetic steel cup is in contact with the isolation sleeve.
4. There is friction between the rotating part and the fixed part.
5. Suction head exceeds or bottom valve clogs.
6. The pump is not fixed.
1. Replace the pump shaft.
2. Replace the shaft sleeve.
3. Adjust the gap or replace parts.
4. Overhaul and replace parts.
5. Reduce the position of the equipment or remove the blockage.
6. Re-fix it.