tailieunhanh - Rolling Bearing Damage 2009 Part 8

Tham khảo tài liệu 'rolling bearing damage 2009 part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Evaluation of running features and damage to dismounted bearings Lip contact Assessment of lip contact Fig. 78 illustrates a well run-in lip surface. Damage to lip and roller faces in roller bearings Scoring due to foreign particles Symptoms Arc-shaped scratches in the lip surface or roller face particularly frequent with tapered roller bearings figs. 79 and 80. Their depth into the lip area depends on the rolling element radius the foreign particle became stuck in. Causes Hard foreign particles in lubricant which are drawn into the area of contact between roller face and lip. Remedial measures Improve lubricant cleanliness. 78 Normal run-in lip contact track in a tapered roller bearing 79 Lip area scoring due to foreign particles 80 Scoring on the face of a tapered roller FAG I 48 Evaluation of running features and damage to dismounted bearings Lip contact Seizure in lip contact Symptoms Partial or large-area welding and deep scratches in the lip and roller face areas figs. 81 and 82. Also lubricant coking in this area. Frequently related to very high loads. Causes Inadequate lubrication with high loads and high speeds quantity or operating viscosity of lubricant too low Inadequate lubrication with high loads and low speeds when there is no hydrodynamic lubricating film between roller face and lip Too high preload of tapered roller bearings Detrimental preload due to heat expansion Skewing of rollers for example in the case of raceway wear ring tilting or insufficient adjustment fig. 81 Axial load too high on cylindrical roller bearings Axial preload of inner ring too high for out-of-square mating surfaces. Remedial measures Improve lubrication increase viscosity EP additives increase lubricant quantity Ensure correct adjustment of bearings 81 Skewing rollers caused seizure marks at the lip when in contact with its edges. 82 Seizure can arise at the roller face and lip when the lubricant supply is inadequate and loads are high. 49 I FAG .