How to determine if the bearings of Pneumatic Roofbolters need to be replaced?
Jun 22, 2026| I. Preliminary Assessment Based on External Observations Before Starting the Machine/Drill:
1. Abnormal Sound and Vibration: Sharp friction sounds, muffled buzzing, or irregular knocking sounds during equipment operation, with vibration amplitude significantly exceeding the normal range, strongly suggest bearing wear or broken ball bearings.
Use a stethoscope close to the bearing housing to listen. A normal bearing produces a smooth, even sound. Irregular noises or periodic disturbances indicate bearing damage.
2. Abnormal Temperature Increase: A rapid temperature rise after bearing operation, exceeding 60℃ for rolling bearings and 45℃ for sliding bearings, or exhibiting irregular temperature fluctuations, indicates bearing wear and jamming.
If lubrication is normal but the temperature continues to rise, the bearing is likely damaged.
3. Decreased Performance: Insufficient motor power in the pneumatic anchor drill, which does not improve after cleaning the oil cup and filter, accompanied by unstable shaking of the drill, is most likely due to bearing wear.
4. Abnormal Lubrication: Disassembly and inspection reveal that the grease is blackened, dried out, or mixed with obvious metal debris, indicating that the bearing is worn and must be replaced.
II. Post-Disassembly Inspection: After initial assessment of the abnormality, disassemble and clean the bearing. Determine replacement based on the following characteristics:
1. Cracks, gaps, or fragments appear on any of the bearing's inner ring, outer ring, balls, or cage.
2. Obvious peeling, pitting, indentation, rust, or scratches appear on the raceway surface or rolling elements.
3. The cage is severely worn, rivets are loose, and the balls cannot be properly secured.
4. The bearing shows obvious discoloration due to overheating, or the seal dust cover is severely damaged.
5. Shaking the bearing outer ring and balls results in a significantly increased clearance; a micrometer measurement shows the clearance exceeds the original factory tolerance.
Conclusion
If external malfunctions point to a bearing problem, or if disassembly reveals any of the above-mentioned damages, the bearing must be replaced to prevent it from shattering and damaging the motor housing, causing more serious equipment damage.
