Technical News

Bearing shells, as key components for transmitting loads and reducing friction in mechanical equipment, are prone to failure due to wear, fatigue spalling and other issues after long-term operation. The traditional method of replacing new bearing shells is costly and time-consuming. In contrast, laser quenching repair processing technology, with its advantages of high precision, low damage, and high efficiency and energy conservation, has become the mainstream solution in the field of bearing shell repair.

I. Core Advantages of Laser Repair Processing for Bearing Shells: Why Choose Laser Quenching Repair?

Compared with traditional repair techniques (such as arc surfacing, electroplating, and flame quenching), laser quenching repair of bearing shells has significant advantages:

1. Small heat-affected zone and extremely low deformation: Laser heating is concentrated in the 0.1-1.5mm area on the surface, with small internal temperature changes in the base material. The overall deformation of the bearing bush can be controlled within 0.005mm, avoiding the warping of the bearing bush caused by traditional flame quenching.

2. Uniform hardness and strong wear resistance: The quenched layer has a fine and uniform structure, with a hardness deviation of ≤HV30. Moreover, a compressive stress layer is formed on the surface (the stress value can reach 200-500 mpa), effectively inhibiting the propagation of fatigue cracks. The service life is 1.5 to 2 times longer than that of new bearing bush.

3. Environmentally friendly and green, with no secondary pollution: The processing does not require the use of welding wires, electroplating solutions or other consumables, and there is no emission of cooking fumes or wastewater, meeting environmental protection requirements.

4. High degree of flexibility and adaptability to complex shapes: Through the numerical control system, laser scanning of any trajectory can be achieved, which is suitable for the repair of bearing shells with oil grooves and irregular structures, solving the problem of complex areas that are difficult to cover with traditional technologies.

5. Low cost and short cycle: The repair cost is only 30% to 50% of that for replacing new bearing shells, and the processing cycle (including inspection, repair, and acceptance) is usually 1 to 3 days, which is much shorter than the 1 to 2-week cycle for purchasing new parts, significantly reducing equipment downtime.

Ii. Applicable Scenarios and Limitations of Laser Quenching Repair Processing for Bearing Shells

1. Applicable scenarios

Wear repair: For uniform wear on the inner surface of bearing shells caused by long-term friction (wear amount ≤1.5mm), such as motor bearing shells, steam turbine bearing shells, machine tool spindle bearing shells, etc.

Local defect repair: Repair scratches, pits and slight spalling on the surface of the bearing bush (defect depth ≤1mm), without the need for overall replacement.

Preventive strengthening: Perform laser quenching on new or slightly worn bearing shells to enhance surface hardness in advance and extend service life (especially suitable for bearing shells with high loads and high-speed operation).

2. Limitations

The repair depth is limited: The depth of the laser quenching layer usually does not exceed 1.5mm. If the wear depth of the bearing bush exceeds 2mm, it needs to be filled by surfacing welding first, and then laser quenching is carried out.

Material compatibility: For bearing shells made of materials prone to cracking such as high-carbon and high-chromium steel, the heating and cooling rates must be strictly controlled to increase the complexity of the process.

The equipment cost is relatively high: The initial investment in laser quenching equipment (especially high-power fiber laser equipment) is considerable, making it suitable for batch repair or high-value bearing bush repair scenarios.

Practical application precautions

Parameter matching is key: Laser parameters for different material bearing shells need to be adjusted specifically (for example, tin-based Babbitt alloy requires low power and fast scanning, while copper alloy requires high power and slow scanning). It is recommended to conduct a small sample test before the first repair to verify hardness and deformation.

Avoid repeated quenching: Repeated quenching in the same area can easily lead to coarse structure and superimposed internal stress. If the repair effect does not meet the standards, the original quenched layer should be removed first (by grinding), and then reprocessed.

Subsequent use and maintenance: Before installing the repaired bearing shells, apply grease. During the initial operation, avoid overloading (it is recommended that the load be controlled within 70% of the rated load, and then gradually increase after 100 hours of operation) to extend the service life.

Choose a professional service provider: Laser quenching has high requirements for equipment precision and the technical skills of operators. It is recommended to choose a service provider with ISO9001 certification and over 5 years of experience in bearing bush repair to avoid repair failure due to non-standard processes.

Iii. Summary

The laser quenching repair processing technology for bearing shells, based on the core principle of "precise heating - rapid cooling - micro-melting repair", has achieved efficient repair and performance enhancement of bearing shells. Compared with traditional methods, it has advantages such as small deformation, strong wear resistance, and low cost. It has been widely applied in the maintenance of bearing shells in fields such as power, machine tools, metallurgy, and shipping. In practical applications, it is necessary to ensure that the repair effect meets the standards through strict pre-detection, parameter optimization and post-processing. At the same time, combined with subsequent maintenance, the service life of the bearing bush can be maximized, providing strong support for enterprises to reduce equipment operation and maintenance costs and minimize downtime losses.