For the staff of the new contact bearing industry, many do not know what the failure mechanism of rolling bearings is. Let's look at it together: mainly abrasive wear, fretting wear, corrosion wear, scratch, gluing, fatigue peeling and so on.
1. Abrasive wear
Because of the different working conditions of bearings, the wear and tear of bearings are also different. In normal working environment, there will also be abrasive particles (such as dust, sand and other hard particles) into the surface of the bearing; when the bearing works, the abrasive particles will treat the bearing surface as a grinding plane, which will damage the surface, so that the performance of the bearing will deteriorate sharply before life, mainly in the start, stop or shaft. When the edge contact occurs between the neck and the bearing, the anticipated life causes geometric shape change, precision loss and bearing clearance increase.
2. Fretting wear
When the rolling bearing is in a non-working state, due to the external vibration load, or in a slightly swinging condition, the relative motion of the rolling element near the contact area of the raceway will occur, because the motion range is very small. Lubricating oil can not be redistributed on the surface of contact zone, which makes the metal surface contact directly and interact with each other under the participation of oxygen, resulting in corrosion of metal surface and metal oxide debris. This phenomenon is called fretting wear of rolling bearings, which is inevitable wear caused by external environment.
3. Corrosion and Wear
During the operation of rolling bearings, water, gas and corrosive media are unavoidable. These substances will cause rust and corrosion of rolling bearings. In addition, in the operation of rolling bearings, they will also be subjected to micro-current and static electricity, which will cause current corrosion of rolling bearings. Rust and corrosion of rolling bearings will cause rings. The pit rust and pear skin rust on the surface of the rolling element eventually result in the failure of the bearing.
4. Scratches
During the operation of rolling bearings, large hard impurities enter into the bearing clearance. When relative motion occurs, impurities will not move at the same speed. The resulting velocity difference will cause shallow marks or deep grooves on the surface, leading to the loss of bearing performance.
5. Cementing
Long-term continuous operation or improper maintenance of bearings, as well as excessive load will make the overall temperature of bearings rise sharply, leading to the rupture of lubrication film; in the absence of lubrication and heavy load, the surface of bearings will appear sticking phenomenon, in the event of relative motion, the surface of bearings will rupture or the bearings will not be able to transport. Turn.
6. Fatigue exfoliation
Long-term heavy-duty work will make the metal on the bearing surface reach its fatigue limit. Crack-like fatigue cracks will appear on the surface perpendicular to the direction of motion, and then gradually expand. Finally, the metal will appear fatigue spalling, resulting in the loss of working performance of the bearing.
Because of the complex use of rolling bearings and the changeable environment, the loss of working performance of rolling bearings is a comprehensive manifestation of various failure modes.
