Bearing scratches caused by roller bearing skidding is a common form of damage. Do you know what roller bearing skidding is? Why does the roller bearing slid? For these series of questions, roller bearing manufacturers share relevant content based on their understanding of bearing knowledge.
When the roller bearing is working, the rollers should perform pure rolling motion on the inner and outer ring raceways. If the drive roller cage is required to have enough drag force, it can overcome its resistance. When the roller drag force is not enough to overcome the resistance, at this time, in addition to rolling, it will also be accompanied by some sliding. Compared with the running speed difference of the inner ring (or outer ring), it is skidding.
Roller bearing skidding is a necessary condition for bearing scratches, but the occurrence of slipping does not necessarily cause surface scratches.
Roller bearing manufacturers believe that some of the factors that cause roller bearings to slip and scratch are, such as shaft vibration and alternating loads, which generate a force that can tear the lubricating oil film and cause the working surface (roller and inner ring raceway work Surface scratches are more common). Compared with fatigue peeling, bearing scratches have a shallower depth and are band-shaped; and compared with normal working surfaces, they are rough and uneven.
Therefore, it is conceivable that the slip injury is the result of material transfer due to the interaction of the uneven metal surface after the lubricant film is destroyed. Some materials are "stained away" to form pits; while the more stained parts protrude above the original surface. In addition, some parts of the working surface are scratched, which is closely related to the alternating load and the degree of damage to the oil film. In severe cases, the excessive frictional heat generated between the roller and the inner ring causes the inner ring to expand, reducing the radial clearance, and causing the bearing to jam.