Why is there noise in the rotor of the inverter motor? -Solutions - Huaqiang Electronic Network

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The noise produced by the rotor of an inverter motor is typically a sound from the fan or brush friction. Occasionally, a loud drum-like noise may occur, which is usually due to sudden starts and stops, especially when reverse braking is frequently performed. This causes the inverter motor to generate fluctuating torque, leading to loosening between the core and the shaft. As a result, the iron core and key may rub against each other, producing audible noise. There are four main reasons for this issue when connecting to the working machine: 1. Loose coupling between the bearing bush of the coupling or pulley and the shaft. When the torque pulsates, the coupling or pulley may rub against the key, creating noise. Measuring the diameter of the shaft and the coupling or pulley can help identify the problem, with dimensional accuracy needing to be checked to 0.01 mm. 2. Wear or deformation of the coupling bolts. If the outer surface of the sleeve is worn or the gap between the bolt and sleeve increases, rubbing sounds may occur under torque ripple. It's recommended to remove the coupling bolts and inspect them for damage. 3. Insufficient lubricating oil in the gear coupling. Oil leakage or lack of lubrication can lead to tooth wear and poor meshing, resulting in abnormal noises such as rubbing sounds. Regular checks of the lubrication level are essential. 4. Slack or worn belts. When under tension, the belt can wear easily. If slippage occurs between the belt and pulley, it can cause abnormal sounds. Checking the belt’s tension and condition, and replacing or adjusting it if necessary, is crucial for smooth operation.