Evaluation of Roller Bearing Rib Contact Figure 78 shows a functioning rib surface. Damage to the rib and roller end face of roller bearings Scratching phenomenon caused by foreign particles: arc-shaped scuffs on the rib surface and roller end face (especially in tapered roller bearings), see Figures 79 and 80 . The depth of the scratch in the rib area is related to the radius of the large end face of the rolling element in which the foreign particles are embedded. Reason: External hard particles in the lubricant enter the contact area between the roller end face and the rib. Remedy: Improve lubricant cleanliness. Adhesion at the rib contact: There is partial or large welding and deep scratching in the contact area between the rib and the roller end face, see Figures 81 and 82. There is also lubricant coking in this area. Often associated with excessive load. Causes: Insufficient lubrication at high load and high speed (too little lubricant quantity or too low operating viscosity) Insufficient lubrication at high load and low speed, no elastic hydrodynamic lubricant film between roller end face and rib tapered roller Preload of sub-bearings too high Excessive preload due to thermal expansion such as roller inclination due to raceway wear, ring inclination or insufficient adjustment, see Figure 81 Axial load of cylindrical roller bearings too high due to mating surfaces The inclination of the inner ring makes the axial load of the inner ring too high. Remedy: Improve lubrication (increase viscosity, EP additives, increase amount of lubricant) Ensure correct adjustment of bearings.