Why the tolerances of each row of rollers in multi-row cylindrical roller bearings should be as consistent as possible?

Aug 07, 2024

Multi-row cylindrical roller bearings are a key component widely used in large-scale equipment such as large and medium-sized electric motors, rolling stock, and lifting and transportation machinery. Their performance and life are directly related to the stability and reliability of the entire mechanical system. In these complex and demanding application environments, the consistent roller tolerances of multi-row cylindrical roller bearings are particularly important. This article will explore in depth from multiple angles why the tolerances of each row of rollers in multi-row cylindrical roller bearings should be as consistent as possible and explain its impact on bearing performance, operating stability, life, and the overall mechanical system.

1. The impact of tolerance consistency on bearing performance

1.1 Uniformity of carrying capacity

Multi-row cylindrical roller bearings are designed to maintain stable operation under high loads. If the tolerances of each row of rollers are very different, then the contact between different rows of rollers and the raceway will be significantly different when subjected to load. Rollers with larger tolerances may enter or exit the load-bearing area early, resulting in uneven load distribution and thus affecting the overall load-bearing capacity of the bearing. Rollers with consistent tolerances can ensure even load distribution and improve the bearing capacity and service life.

1.2 Improvement of rotation accuracy

The rotation accuracy of a bearing is one of the important indicators to measure its performance. Rollers with consistent tolerances can ensure that the contact state between each row of rollers and the raceway is consistent during the rotation of the bearing, thereby reducing vibration and noise caused by tolerance differences. On the contrary, rollers with large tolerance differences will cause the bearing to produce periodic vibrations during rotation, reduce rotation accuracy, and even cause bearing failure.

The picture above is a drawing of the four-row cylindrical roller bearing Z-524229.ZL issued by FV Bearing. The mutual difference of the four rows of rollers is controlled below 0.01MM.

2. The impact of tolerance consistency on work stability

2.1 Reduce vibration and noise

Vibration and noise are common problems during bearing operation. They not only affect the smooth operation of the equipment but may also cause interference with the surrounding environment. Rollers with consistent tolerances can ensure smooth contact between each row of rollers and the raceway when the bearing rotates, thereby reducing vibration and noise caused by changes in contact status. It is of great significance for improving the operational stability of the equipment and reducing noise pollution.

2.2 Improve repeat positioning accuracy

In applications that require high-precision positioning, the repeatable positioning accuracy of bearings is crucial. Rollers with consistent tolerances ensure that the bearing can accurately return to its original position after multiple rotations, thereby improving positioning repeatability. It is particularly important for precision machinery and automation equipment, which can significantly improve the processing accuracy and reliability of the equipment.

3. The impact of tolerance consistency on bearing life

3.1 Reduce wear and fatigue

Rollers with consistent tolerances can ensure that the contact state between each row of rollers and the raceway is consistent during bearing operation, thereby reducing wear and fatigue caused by contact stress concentration. On the contrary, rollers with large tolerance differences will lead to uneven distribution of contact stress, accelerate the wear of rollers and raceways, and shorten the service life of the bearing.

3.2 Improve overall reliability

As an important component in the mechanical system, the reliability of bearings directly affects the operation of the entire system. Rollers with consistent tolerances can reduce faults and failures caused by tolerance differences and improve the overall reliability of the bearing. It is of great significance to ensure the continuous and stable operation of the mechanical system.

Look, this is the four-row cylindrical roller bearing outer assembly R313824 manufactured by FV Bearings.

4. Ways to achieve tolerance consistency

4.1 Optimization of manufacturing process

In order to ensure the tolerance consistency of each row of rollers in a multi-row cylindrical roller bearing, the manufacturing process must be optimized. By using high-precision processing equipment, improving process flow, and strengthening quality inspection, the processing accuracy and tolerance consistency of rollers can be significantly improved.

4.2 Control of assembly process

During the assembly process, assembly should be carried out in accordance with the design requirements to ensure the matching accuracy between each row of rollers and the inner and outer rings. At the same time, cylindrical rollers of the same model are assembled in groups to ensure consistent tolerances of rollers in the same size group, thereby improving the overall performance of the bearing.

4.3 Strict quality management

Establish a complete quality management system and conduct strict quality control on all aspects of roller production, processing, testing, and assembly. Through regular testing and data analysis, tolerance deviation problems are discovered and corrected in a timely manner to ensure the manufacturing quality and performance of the bearings.

5. Conclusion

To sum up, the tolerance consistency of each row of rollers in a multi-row cylindrical roller bearing has an important impact on the performance, working stability, lifespan of the bearing, and reliability of the overall mechanical system. In order to ensure the high performance and reliability of bearings, the tolerance consistency of rollers must be strictly controlled from multiple aspects such as manufacturing technology, assembly process and quality management. Only in this way can the urgent needs of modern mechanical equipment for high-precision, high-reliability, and long-life bearings be met.