Factors Affecting the Service Life of Crossed Roller Bearings and Methods for Extending Their Service Life

Every mechanical component has a certain service life. As time passes or due to wear and tear, its performance gradually deteriorates, eventually failing to meet the demands of production and use. Below, the editor from Aowite will provide you with a detailed explanation of the factors that affect the service life of cross roller bearings, as well as methods for extending their service life.

I. Factors Affecting the Service Life of Crossed Roller Bearings

1. Influence of the number of rollers: When the number of rollers is relatively small (Z = 15), the bearing’s fatigue life is very low, at approximately 540 hours. As the number of rollers increases—reaching full complement (Z = 34)—the load-carrying capacity of the crossed roller bearing improves, and its fatigue life also increases accordingly, reaching about 3,879 hours, an improvement of roughly seven times. However, the number of rollers cannot be increased indefinitely. Moreover, from the perspective of manufacturing processes and production costs, increasing the number of rollers will also lead to higher costs as well as greater difficulties in manufacturing and installation.

2. Influence of Load Magnitude: At different bearing speeds, the bearing fatigue life decreases as the load increases. The higher the bearing speed, the less significant the effect of radial load on bearing life.

3. Influence of Rotational Speed: Under different radial load conditions, the fatigue life of cross roller bearings varies with changes in rotational speed. As the bearing’s rotational speed increases, the centrifugal force acting on the bearing also increases, leading to higher contact stresses between the bearing rollers and the outer race. Meanwhile, under different radial load conditions, the greater the load, the smaller the impact of rotational speed on the fatigue life.

4. Influence of Pitch Circle Diameter: As the pitch circle diameter of a cross roller bearing increases, the bearing’s fatigue life continuously decreases. This is mainly because, as the pitch circle diameter grows, the centrifugal force acting on the bearing also increases, leading to higher contact stress between the rollers and the outer race, thereby reducing the bearing’s fatigue life.

II. Methods for Extending Service Life

1. Proper Selection: Only when an item is used in the right place can it truly realize its full value. Similarly, selecting the right bearing has a direct impact on extending its service life. The selection should be based on the bearing’s structure, its theoretical service life, and its specific application. Depending on the particular application, it may be necessary to choose bearings that have been specially designed to meet specific requirements regarding precision, clearance, retainer design, lubricant, and other factors. However, there is no fixed sequence or set of rules for selecting bearings; rather, the primary consideration should always be the conditions and performance characteristics required for the bearing itself.

2. Proper Installation: The correct assembly procedure is also crucial for extending the service life of cross roller bearings. Whether the assembly method is appropriate or not directly affects whether a proper clearance can be maintained. If the bearing is improperly installed or removed, it may result in indentation on the raceway at best, and at worst, render the bearing unusable. If the clearance is too small, it will increase the additional torque acting on the cross roller bearing. Moreover, an increased angular displacement between the bearing’s centerline and the centerline of the bearing bore will inevitably shorten the working life of the cross roller bearing—these issues should be avoided as much as possible.

3. Proper Use: Crossed roller bearings are high-precision components, and their use must be handled with commensurate care. Keep the bearing and its surrounding area clean—avoid subjecting the bearing to strong impacts, use appropriate handling tools, and take measures to prevent rusting of the bearing.

The above is a summary of the factors affecting the service life of crossed roller bearings and methods for extending their service life. By selecting the right model, ensuring proper installation, and following standardized operating procedures, we can to some extent extend the bearing’s service life and reduce production costs. At Aowei Bearing, we have extensive experience in manufacturing crossed roller bearings and offer custom-made solutions tailored to specific requirements. If you have any needs, please feel free to call us for further information and consultation.