In industrial sites, more than half of equipment downtime is related to bearing failures. Many users attribute bearing damage to quality issues, but in fact, less than 10% of failures are caused by material or manufacturing defects. The vast majority of bearing damage stems from external factors such as improper use, non-standard installation, incorrect lubrication, contamination, and overload. Understanding the causes of failure is the key to fundamentally extending bearing life.

The leading cause of failure is improper lubrication, accounting for over 40%. Excessive grease causes churning and overheating, while insufficient grease fails to form an effective oil film; using mismatched grease (e.g., high-temperature grease for low-temperature applications or ordinary grease for high-speed operations) will quickly damage the friction pair. When grease ages, becomes contaminated, or mixes with water, its lubricating function deteriorates sharply, eventually leading to wear, gluing, and pitting.

Second is contaminant intrusion. Dust, metal chips, sediment, and moisture entering the bearing cause abrasive wear, surface scratches, and corrosion. Contamination is especially severe in open bearings or those with failed seals. Equipment operating in harsh environments for a long time must adopt reliable sealing structures.

Third is improper installation and fit. Too small an interference fit on the inner ring causes inner ring creep, while too large an interference deforms the raceway; an overly tight fit on the outer ring leads to excessive preload and additional stress. Direct hammering during installation, uneven force, and misalignment between the shaft and housing bore will cause early fatigue damage.

Fourth is overload and impact. Instantaneous shock, frequent start-stop, and overloading subject bearings to stress far exceeding the design value, resulting in surface spalling, cracks, and even fracture.

To effectively prevent failures, enterprises should establish standardized procedures: strictly select grease according to the manufacturer’s recommendations; keep the environment clean and use sealed bearings; standardize installation tools and processes to avoid impact deformation; regularly monitor temperature, vibration, and noise; and avoid long-term overloading. Meanwhile, choosing stable and reliable bearing brands can significantly improve system safety.