What are the causes of cross roller bearing failure, and how can you identify them?

The causes of cross roller bearing failure can generally be categorized into two types: rotational failure (fatigue failure) and wear-related failure (loss of precision). Rotational failure occurs when the bearing loses its ability to function and stops rotating, while loss of precision refers to situations where the bearing’s accuracy falls below design specifications due to wear and other factors. Below, our Ovite editor will provide a detailed introduction to the causes of cross roller bearing failure and offer guidance on how to accurately identify these failure causes in daily use.

I. Causes of Crossed Roller Bearing Failure

1. Fatigue failure—specifically, contact fatigue failure—is one of the most common failure modes in various types of bearings. It arises from the repeated action of cyclic contact stresses on the surface of cross roller bearings. The contact fatigue spalling on the surfaces of bearing components is a process during which fatigue cracks initiate, propagate, and eventually lead to material removal. Initially, contact fatigue cracks typically originate at locations on the contact surface where the orthogonal shear stress is relatively high. These cracks then propagate toward the surface, resulting in either pitting or small flake-like spalling. The former is referred to as pitting or pitted spalling, while the latter is known as shallow spalling. If the initial crack originates at the interface between the hardened layer and the core, causing premature spalling of the hardened layer, this phenomenon is termed hardened-layer spalling.

2. Wear-induced failure—adhesive wear and abrasive wear—are among the most common failure modes on bearing surfaces. Sliding wear refers to the continuous loss of surface metal caused by relative sliding friction between bearing components. Continuous wear leads to changes in component dimensions and shapes, increases in bearing clearance, and deterioration of the working surface topography, thereby compromising rotational accuracy and rendering cross roller bearings unable to function properly. Sliding wear can be categorized into several forms, including abrasive wear, adhesive wear, corrosive wear, and fretting wear; among these, abrasive wear and adhesive wear are the most common. These two types of wear often result in chisel-like or furrow-like scratches on bearing surfaces. Foreign hard particles typically originate from dust in the air or impurities in lubricants. Adhesive wear primarily occurs because the asperities on the friction surfaces cause uneven distribution of contact pressure, leading to localized temperature rises due to frictional heat. This can cause the lubricant film to break down; in severe cases, the surface layer metal may even partially melt. The contact points then undergo a cyclical process of adhesion, tearing, and re-adhesion, which, under extreme conditions, can lead to welding and seizing of the friction surfaces.

II. Methods for Identifying the Causes of Crossed Roller Bearing Failure

1. Obtain operational data from the cross roller bearing monitoring device.

2. Prepare a checklist to record all observation items.

3. Collect samples of used lubricants, package them separately, and label them appropriately.

4. Collect unused lubricant samples and record their specification data or batch information.

5. Check for external factors in the application environment of cross roller bearings.

6. Disassemble the equipment.

7. Inspect the condition of parts in other areas.

8. Before disassembly, mark the installation positions of the cross roller bearing and other components.

9. Measure the dimensions, roundness, and taper of the cross roller bearing and the cross roller bearing housing.

10. After completing the disassembly, before cleaning the components, record your observations on the distribution and condition of the lubricant.

11. Clean the parts and record their information.

12. Analyze the condition of the internal rolling contact surfaces, load zones, and corresponding external surfaces.

13. Apply rust-preventive oil and repackage the crossed roller bearing to prevent corrosion.

The above is a summary of the causes of cross roller bearing failure and methods for identifying those causes. We hope this information is helpful to everyone. In addition to the proper and routine application of bearings—paying attention to correct usage and maintenance practices—regular inspections are also crucial. At Aowite, we have extensive experience in the production of cross roller bearings. If you have any needs, feel free to give us a call for more information.