How to judge whether the bearing is damaged?

Aug 29, 2024

As an important component in mechanical equipment, the operating status of the bearing directly affects the performance and life of the entire equipment. Therefore, timely and accurate judgment of whether the bearing is damaged is of great significance to ensure the normal operation of the equipment and prevent the expansion of faults. The following will introduce in detail how to judge bearing damage from multiple aspects.

1. Observe the appearance

First, by observing the appearance of the bearing, you can preliminarily judge whether it is not very accurate. Under normal circumstances, the bearing surface should be smooth, without wear, cracks, and other defects. If the bearing surface is found to have obvious wear, depression, cracks, peeling, or color changes (such as color changes caused by overheating), the bearing is likely faulty. At this time, the machine should be stopped and checked in time to avoid further expansion of the fault.

2. Listening to the sound

Sound is an important basis for judging the operating status of the bearing. When the bearing is operating normally, its sound should be smooth and uniform. If the bearing makes abnormal sounds, such as metal impact, friction, or periodic humming, it indicates that the bearing may be faulty. Through training and the use of professional listening devices or listening sticks, the sound characteristics of the bearing can be more accurately identified to determine whether it is damaged.

3. Measure temperature and vibration

When the bearing is operating normally, its temperature and vibration should be stable within a certain range. If the bearing temperature is found to be abnormally high or the vibration is abnormally increased, the bearing likely has a fault. At this time, tools such as thermometers and vibrometers can be used for measurement further to determine the cause and extent of the fault. The abnormal temperature increase may be caused by insufficient lubrication, excessive load, or internal wear of the bearing, whereas while unbalanced, loose, or damaged bearings may cause an abnormal increase in vibrations.

4. Check lubricant

The state of the lubricant is also an important indicator for judging whether the bearing is damaged. By sampling and analyzing the lubricant, you can observe its degree of contamination, whether foreign matter or metal powder is mixed in, etc. If the lubricant becomes turbid or contains a large amount of metal powder, it indicates that wear or damage may have occurred inside the bearing. In addition, the loss or deterioration of the lubricant can also cause bearing failure, so the lubricant should be checked and replaced regularly.

5. Specific damage forms and judgments.

Cracks and fragments: If cracks and fragments appear on the inner and outer rings, rolling elements, or cages of the bearing, it indicates that the bearing has been severely damaged and needs to be replaced immediately.

Stripping: Stripping occurs on the running surface of the bearing, usually due to excessive load, poor installation, or poor bearing box accuracy. After stripping, the surface is obviously concave and convex, and the use conditions and bearing selection need to be rechecked.

Jams and indentations: Significant jams and indentations on the raceway surface, rolling elements, or cages are also common manifestations of bearing damage. These damages are usually caused by poor lubrication, foreign matter intrusion, or improper installation.

Overheating and discoloration: Overheating of the bearing can cause color changes (such as fading from gold to blue) and, in severe cases, even bearing deformation and lubricant failure. High electrothermal loads, improper heat channels, or insufficient cooling usually cause overheating.

Cage damage: Cage damage may be caused by excessive torque loads, high-speed rotation, or high vibration. A damaged cage can cause rolling elements to scatter, seriously affecting the normal operation of the bearing.

Rust and corrosion: Rust and corrosion occur on the bearing surface, usually due to poor storage conditions, improper packaging, or exposure to corrosive environments. Rust and corrosion will increase the wear and damage of the bearing.

Wear: Wear on the bearing surface can cause dimensional changes and multiple wear marks. Wear is usually caused by foreign matter mixed into the lubricant, poor lubrication, or roller deflection.

6. Use professional detection tools

In order to more accurately determine whether the bearing is damaged, you can also use professional detection tools, such as intelligent handheld bearing fault detectors, vibration fault detectors, etc. These tools can monitor the vibration, temperature, and other parameters of the bearing in real time and determine the operating status of the bearing through data analysis.

FV engineers are detecting bearing runout.

7. Summary

To determine whether the bearing is damaged, it is necessary to consider multiple factors, including appearance, sound, temperature, vibration, and the state of the lubricant. At the same time, the use of professional detection tools can further improve the accuracy and efficiency of the judgment. Once the bearing shows signs of damage, it should be stopped for inspection and appropriate maintenance measures should be taken in time to ensure the normal operation of the equipment and extend the service life of the bearing.