Analysis and solution of abnormal sound of motor bearing
June 29 01:04:10, 2025
**Analysis and Solution of Abnormal Sounds in Motor Bearings**
Home > Bearing Knowledge > Analysis and Solution of Motor Bearing Noise
Source: Bearing Network | Date: January 5, 2013
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**1. "Clicking" Sound – Causes and Solutions**
The sound is often described as a repetitive "click-click-click." This noise usually occurs due to the vibration between the bearing's rolling elements and the raceway. It can happen even with smooth bearings and is more common when there is high torque, load, or radial clearance.
**Solutions:**
- Improve the accuracy of the bearing fit.
- Choose a bearing with smaller clearance or apply a preload.
- Reduce moment loads and minimize device errors.
- Use high-quality grease for better performance.
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**2. "Buzzing" Sound – Causes and Solutions**
This type of noise is typically heard during no-load operation and may resemble a buzzing or humming sound. It can also occur due to axial imbalance in the motor or a "beep" sound when turning the motor on or off.
**Causes:**
- Poor alignment of the shaft.
- Inadequate lubrication or improper installation.
**Solutions:**
- Use smooth and functional grease.
- Apply a proper preload and reduce device errors.
- Choose bearings with small radial clearance.
- Improve the rigidity of the bearing housing.
- Ensure proper centering of the bearing.
Note: Pay special attention to the curvature of the inner and outer grooves — select small groove curvature (02) or large groove curvature (01) based on the application.
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**3. "Rust" Sound – Causes and Solutions**
A rust-related noise usually appears after the paint on the bearing housing dries, leading to chemical corrosion on the end face, outer race, and rolling channels. This results in an abnormal sound due to surface damage.
**Solutions:**
- Rotate the rotor and ensure the housing is properly dried.
- Lower the motor temperature if possible.
- Choose appropriate paint types.
- Improve the ambient temperature around the bearing.
- Use non-corrosive greases such as silicone oil instead of mineral oil.
- Consider vacuum impregnation to prevent contamination.
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**4. "Impurity" Sound – Causes and Solutions**
This sound is caused by dirt or foreign particles in the bearing or grease. The noise is irregular and may vary in intensity.
**Solutions:**
- Use high-quality grease.
- Ensure cleanliness before grease application.
- Improve the sealing system of the bearing.
- Maintain a clean installation environment, especially for high-speed motors.
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**5. High-Frequency "Ticking" Sound – Causes and Solutions**
This sound is characterized by a high-pitched, rhythmic "tik-tik-tik," and its frequency changes with the speed of the bearing. It is mainly caused by waviness on the raceway.
**Solutions:**
- Improve the machining quality of the raceway to reduce waviness.
- Minimize any mechanical impact.
- Adjust the clearance and preloading.
- Ensure accurate alignment of the shaft and bearing components.
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**6. Excessive Heat – Causes and Solutions**
If the bearing becomes excessively hot during operation, it can lead to premature failure.
**Causes:**
- Over-greasing increases internal friction.
- Too small clearance leads to excessive internal load.
- Device misalignment or seal interference.
**Solutions:**
- Select the correct type and amount of grease.
- Adjust the clearance and preloading.
- Check the condition of the free-end bearing.
- Improve the accuracy of the bearing housing and installation method.
- Enhance the sealing system to prevent contamination.
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**7. Poor Bearing Feel – Causes and Solutions**
When manually rotating the rotor, you may feel resistance or roughness from the bearing, indicating potential issues.
**Causes:**
- Excessive clearance.
- Improper fit between the inner diameter and the shaft.
- Damage to the raceway.
**Solutions:**
- Adjust the clearance to an optimal level.
- Choose the right bearing type for the application.
- Improve the accuracy of the bearing and reduce channel damage.
- Use suitable grease that enhances performance and longevity.
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**Related Bearing Knowledge:**
- Self-lubricating bearings (oil-free bearings)
- Bearing conventions and preparation work
- Koyo bearing utilization and lubricant replacement
- Extending the service life of bearings
- Hollow shaft and rolling bearing equipment
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This article is originally published on China Bearing Network.
Link: http://www.chinabearing.net
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