1. Immediate shutdown and safety confirmation
After discovering abnormal noise, the first step is to stop the machine immediately for inspection to avoid the expansion of the fault and cause more serious damage. Under the premise of ensuring safety, disconnect the power supply and investigate the specific source of the noise to confirm whether the noise comes from the reducer itself, the motor or other connected components.
2. Core troubleshooting and solutions
1. Check gear meshing and wear
Fault characteristics: If you hear periodic "click" sounds, sharp metal friction sounds or knocking sounds, it usually indicates pitting, gluing, wear or even broken teeth on the gear tooth surface.
Treatment method: Disassemble the reducer and check the condition of the gear tooth surface. If the tooth surface is damaged or chipped, it is necessary to replace it with a new gear of the same model; at the same time, clean the remaining metal debris inside the gear box to ensure that the meshing clearance of the new gear meets the standard (usually 0.1-0.2mm) to avoid impact caused by too large a clearance or aggravated friction if it is too small.
2. Check the installation accuracy and connections
Fault characteristics: Installation accuracy issues are the most common cause of abnormal noise (accounting for about 60%). If the motor shaft and reducer are not concentric, the flange surface is not flat, or the fastening bolts are loose, it will cause uneven gear meshing and produce regular meshing noise or resonance.
Treatment method: Remove the reducer and reinstall it to ensure the cleanliness and flatness of the installation surface. Use a dial indicator or laser alignment tool to check concentricity, and the radial deviation should be controlled to ≤0.05mm. Retighten all bolts to the specified torque and add lock washers if necessary.
3. Check the status of the lubrication system
Fault characteristics: The noise is loud at the beginning, decreases after heating, or is accompanied by high-frequency sharp sounds. This is mostly due to uneven distribution of grease, insufficient oil, deterioration of oil, or mixed use, resulting in direct metal contact of the gears.
Solution: Check whether the oil level is within the standard range. Clean the old grease that has dried up inside, and add an appropriate amount of special lubricating oil/grease that matches the model according to the manufacturer"s specifications (usually the filling amount is controlled at 1/3 to 1/2 of the gear meshing surface). After filling, manually turn it several times to make the lubrication even, then power on and test.
4. Check the bearing operating status
Fault characteristics: If you hear irregular metal impact sounds, low-frequency continuous roaring or "buzzing" sounds, it may be that the bearings are worn, the cage is broken, or the clearance is too large.
Treatment method: Disassemble and check whether the inner and outer rings and raceways of the bearing are worn or rusted. After confirming the damage, use special tools (such as bearing pullers) to replace high-precision bearings of the same specification. When installing, apply a small amount of grease and press-fit slowly to ensure flexible rotation without jamming.
5. Evaluate load and resonance issues
Fault characteristics: The noise suddenly increases within a specific speed range and is accompanied by low-frequency vibration of the entire equipment. This is usually due to structural resonance. If overload operation continues, the elastic deformation of the gear will increase and the noise will increase.
Solution: Verify whether the actual load is within the rated torque range of the reducer to avoid long-term overloading. Resonance problems can be solved by fine-tuning the motor speed to avoid the resonance range, adding vibration damping pads, or changing the stiffness of the installation foundation.
3. Professional maintenance suggestions
For precision reducers with complex structures (such as harmonic reducers, RV reducers, etc.), once their internal core components (such as flexsplines) are worn or deformed, the transmission accuracy will be greatly affected. Blind disassembly and repair without permission is strictly prohibited. It is recommended to contact the original manufacturer or professional service provider directly for inspection and component replacement to ensure long-term stable operation of the equipment.
