Measures taken 3.1.1 Mark the disassembled parts When there are multiple bearings of the same type in the same bearing arrangement, all the bearings must be numbered and their positions must be recorded. The side of the bearing configured to be used shall be marked including the installation position of the bearing. Mark the radial installation direction of the ferrule according to the external force. 3.1.2 Finished bearing test Noise test Test axial/radial clearance Test radial/axial runout Test friction torque 3.1.3 Bearing removal If the sealed bearing has grease leakage, determine the amount of grease. Carefully remove the dust cover or seal from the sealed bearing, avoiding deformation as much as possible. Evaluate the grease distribution in the bearing. Grease sampling; if there is an irregular lubrication pattern, take multiple samples. If the disassembly is destructive, you can damage the parts that will not affect the cause of the failure (such as cutting off or turning off the ribs of the small diameter end of the tapered roller bearing). If damage is unavoidable during the disassembly process, it must be marked and recorded. To evaluate the bearing parts, we must first carefully observe the main running surface and mounting surface. It is recommended to inspect bearing components with a microscope, which is usually necessary for most bearings. The following procedures are often applicable to the evaluation of bearing parts: Evaluation: Mating surface (axial mating surface, inner ring inner hole, outer ring outer surface) Raceway rib seal mating surface/contact surface Rolling element (outer surface And the end face of the roller) Cage seals are sometimes required for other tests to find out the cause of the failure. These inspection items include: lubricant analysis, measurement, electron microscope testing, etc. In the bearing laboratory, the relevant staff are willing to help with product development (refer to Chapter 4). A choice is often made: continue to use the bearing or replace it now? When the failure is obvious, there is no doubt that these procedures must be followed. However, such failures are rare. The evaluation of the bearing can usually reflect its operating conditions. When an abnormal condition and its cause are detected, it is usually possible to avoid further damage. The following sections include a description of the phenomenon, its cause, and appropriate and preventive measures that can be taken.