How to determine if a ball mill needs overhaul?

1. Wear of core components
1. Main bearings and hollow shafts
Bearings worn to more than 50% of the designed clearance or with scratches or cracks should be replaced.
Hollow shaft necks with surface wear or deformation (such as excessive ovality) should be repaired or replaced.
2. Gears and transmission system
Gear tooth wear exceeding 20% ​​of the tooth thickness or with broken teeth should be replaced.
Broken coupling pins or bent drive shafts should be corrected or replaced.
3. Cylinders and liner plates
Cracks, deformation, or wear to 2/3 of the original thickness of the cylinder require overhaul.
2. Abnormal operating symptoms
Vibration and noise: Abnormal vibration (amplitude exceeding 0.5mm) or unusual gear noise indicates an imbalance in the transmission system.
Current fluctuation: Sustained high current may be due to cylinder deformation or bearing seizure. Bearing Temperature: If the main bearing temperature exceeds 60°C for a prolonged period, the bearings must be inspected, lubricated, or replaced.

III. Maintenance Intervals and Standards

Routine Interval: A comprehensive overhaul is required every 2-5 years, adjusted based on wear.

Mandatory Overhaul Conditions:
Cracks in the cylinder welds or frequent breakage of liner bolts.
Pitting corrosion on the reducer gears exceeding 30% or bearing failure.

IV. Auxiliary Inspection Methods

Non-destructive Testing: Perform ultrasonic or magnetic particle inspection on the cylinder and hollow shaft. Any internal cracks detected require immediate attention.

Oil Analysis: Excessive metal particle content in the lubricating oil (e.g., iron filings concentration >100 ppm) indicates component wear.