The article analyzes and summarizes common faults and their causes in the operation of rolling bearings, which are the most crucial support components in operating equipment and are also prone to failures. It explains the diagnostic methods for common bearing faults and provides practical recommendations for handling them, ultimately extending the bearing's service life. This article offers valuable insights for routine equipment maintenance.
Ⅰ. Common Faults and Analysis of Rolling Bearings
Rolling bearing faults manifest in excessive temperature in the bearing installation area and noise during bearing operation. The analysis is as follows:
1.1 Excessive Bearing Temperature
During equipment operation, the bearing installation area allows for a certain range of temperature variation. When touching the bearing housing by hand, it should not feel excessively hot. Excessive bearing temperature can be caused by various factors, including inadequate or deteriorated lubricating oil, high lubricating oil viscosity, overly tight mechanical assembly, over-tightened bearing installation, rotation of the bearing seat on the shaft or in the housing, excessive load, or damage to the bearing cage or rolling elements.
1.2 Bearing Noise
While rolling bearings may produce slight operational sounds, abnormal noises or impact sounds indicate bearing faults. The causes of bearing noise are diverse, including surface wear on the inner and outer raceways, fatigue-related metal spalling, insufficient lubrication resulting in dry friction, and broken or loose components such as cages or rolling elements.
Ⅱ. Analysis of Bearing Damage
When disassembling rolling bearings for inspection, the condition of the bearings can provide insights into the nature of the fault and its causes. Specific analyses are as follows:
Surface Metal Spalling can occur due to cyclic stress from the rolling elements and inner and outer raceways. Excessive loads can exacerbate this fatigue-related spalling. Improper installation, shaft bending, or misalignment can also lead to surface spalling.
Bearing Scorching: Scorching of the bearing is indicated by a tempering color on the raceways or rolling elements. Insufficient or poor-quality lubrication and overly tight bearing assembly can cause scorching.
Plastic Deformation: Uneven pitting on the bearing's raceways suggests plastic deformation caused by local stresses exceeding the material's yield limit. It can occur in low-speed rotating bearings subjected to heavy static or impact loads.
Cracks in Bearing Raceways: Bearing raceway cracks may result from overly tight fits, loosening of the inner or outer ring, deformation of bearing components, or poor surface finishing during installation.
Cage Fracture: Inadequate lubrication, breakage of rolling elements, or misalignment can cause cage fracture.
Metal Adhesion to Rolling Elements: This can occur when rolling elements become stuck in the cage or due to insufficient lubrication.
Severe Wear on Raceways: Severe wear on raceways may be caused by inadequate lubrication or the use of inappropriate lubricants.
Ⅲ. Diagnosis and Treatment of Rolling Bearing Faults
Common diagnostic methods for bearing faults include acoustic listening, magnetic plug inspection, and temperature measurement.
3.1 Acoustic Listening
Using acoustic listening tools, abnormal bearing sounds can be identified, and the nature of the problem can be inferred. Various abnormal sounds may indicate specific issues, such as insufficient lubrication, surface wear, fatigue-related damage, or foreign particle contamination. These issues should be addressed accordingly.
3.2 Magnetic Plug Inspection
Magnetic plug inspection involves monitoring the presence of metal particles in lubricating oil. Different types of wear particles can provide insights into the condition of the bearing. This method is particularly suitable for monitoring larger equipment with dedicated oil return channels.
3.3 Temperature Measurement
Temperature measurements can be used to monitor bearing conditions. An abnormal increase in temperature indicates a problem, but this method may not detect localized defects in their early stages. Regular temperature measurements can help identify potential issues and allow for timely adjustments.
By analyzing common causes of rolling bearing faults and studying common damage patterns, this article has provided practical diagnostic methods and recommended actions for addressing these faults. Implementing these strategies can extend the service life of rolling bearings, offering valuable guidance for routine equipment maintenance and establishing a foundation for high-efficiency production.