Analysis of the failure causes of radial bearings

Jun 05, 2024

Introduction

As crucial members of the mechanical equipment operation and maintenance team, your understanding of the failure causes of radial bearings is directly linked to the performance and life of the entire equipment. In real-world scenarios, radial bearings often fail for various reasons, leading to equipment downtime, increased maintenance costs, and other issues. Therefore, your in-depth analysis of the failure causes of radial bearings is of immense significance for improving equipment reliability and reducing maintenance costs. This article will assist you in this analysis by providing insights into the failure causes of radial bearings from multiple aspects, supported by relevant figures and information.

Comprehensive Analysis of the Failure Causes of Radial Bearings

Fatigue failure

Fatigue failure is one of the common failure forms of radial bearings. It is mainly due to the fact that fatigue cracks are generated inside the bearing material under the action of alternating loads and gradually expand, eventually leading to bearing fracture. The causes of fatigue failure mainly include the following aspects:

(1) Insufficient bearing material performance: The selection and manufacturing quality of bearing materials will affect their fatigue life. If the material strength, toughness, and other properties are insufficient, fatigue failure is likely to occur.

(2) Too large or too small load: The load refers to the force that the bearing is subjected to during operation. If the load is too large, it will cause the bearing to bear excessive stress, accelerating the generation and expansion of fatigue cracks. On the other hand, if the load is too small, it may cause tiny cracks on the bearing surface, which will gradually expand under the action of alternating loads.

(3) Poor lubrication: Poor lubrication will increase the friction on the bearing surface and increase the temperature, thereby accelerating material fatigue.

Wear failure

The wear failure is another common failure form of radial bearings. It is mainly caused by the relative sliding friction between the bearing surfaces, resulting in continuous wear and broken of the metal on the working surface. The main causes of wear failure include the following aspects:

(1) Poor lubrication: Poor lubrication will increase the friction on the bearing surface and accelerate wear. In addition, if the lubricant contains impurities or contaminants, it will also aggravate the wear of the bearing.

(2) Too large or too small bearing clearance: Too large bearing clearance will cause excessive relative displacement and vibration of the bearing during operation, thereby accelerating wear, while too small clearance may cause excessive contact stress on the bearing surface, which will also accelerate wear.

(3) Foreign matter intrusion: If foreign matter, such as hard particles and metal chips, intrudes into the bearing, they will produce plow-shaped scratches on the bearing surface, accelerating wear.

The above picture shows an axial crack on the inner ring raceway surface of a spherical roller bearing.

Corrosion failure

Corrosion failure refers to the failure of the bearing surface metal due to a chemical reaction between the bearing surface metal and the medium when the bearing is running in a corrosive medium. The main causes of corrosion failure include the following aspects:

(1) Medium corrosiveness: If the medium in contact with the bearing is highly corrosive, such as acid or alkali, it will corrode the metal on the bearing surface.

(2) Poor sealing: Poor sealing will cause corrosive media to intrude into the bearing, thereby accelerating corrosion failure.

(3) Poor material corrosion resistance: If the bearing material itself has poor corrosion resistance, it is easy to fail due to corrosion in a corrosive medium.

Improper installation

Improper installation is also an important cause of radial bearing failure. Improper installation mainly includes the following aspects:

(1) Improper bearing installation position: If the bearing is installed in an incorrect position, such as tilting or skewing, the bearing will be subjected to uneven load and stress during operation, thus accelerating failure.

(2) Overtight or loose bearing installation: Overtight installation will cause excessive stress inside the bearing, accelerating fatigue failure. In contrast, over-loose installation may cause excessive relative displacement and vibration during operation, thus accelerating wear and corrosion failure.

(3) Failure to clean and inspect before installation: If the bearing is not thoroughly cleaned and inspected before installation, impurities and foreign matter may be present inside the bearing, thus accelerating failure.

Conclusion

In conclusion, while there are numerous reasons for the failure of radial bearings, including fatigue failure, wear failure, corrosion failure, and improper installation, there is also a significant potential for improvement. By implementing measures such as selecting suitable bearing materials and lubricants, optimizing bearing design, and strengthening bearing installation and maintenance, we can effectively avoid or reduce the failure of radial bearings. It not only ensures the stable and reliable operation of radial bearings in mechanical equipment but also can reduce maintenance costs and enhance equipment performance.