Determine whether the bearing can be reused

To determine whether a bearing can be reused, one must consider the extent of the damage to the bearing, the performance of the machine, its importance, operating conditions, and the inspection cycle, etc. After considering these factors, a decision can be made.

If the inspection reveals damage or abnormal conditions in the bearing, the specific details of the damage should be identified, and countermeasures should be formulated. Additionally, if the inspection results show the presence of the following defects, the bearing cannot be reused, and a new one must be replaced.

a. Either the inner ring, the outer ring, the rolling elements, or the cage has cracks or fragments.
b. Either the inner or outer ring, or the rolling elements, have any peeling.
c. The raceway surface, edge guard, and rolling elements have significant scratches or damage.
d. Where the retaining rings are severely worn or the rivets are loose.
e. The raceway surface and rolling elements are rusty and have scratches.
f. With significant indentations and scratches on the rolling surface and rolling elements.
g. There is creep on the inner diameter surface of the inner ring or on the outer diameter of the outer ring.
h. With severe overheating discoloration.

The sealing ring and dust cover of the grease-sealed bearing have been severely damaged.
(1) Inspection and Fault Handling During Operation
The ongoing inspection items include the rolling sound of the bearings, vibration, temperature, and the lubrication status etc. The details are as follows:
1. The sound of the bearings' rolling motion
The operation of the bearings is inspected by using a sound detector to measure the volume and quality of the rolling sounds. Even if there are slight damages such as peeling on the bearings, abnormal sounds and irregular sounds will be emitted, and these can be distinguished using the sound detector.
Vibration of the bearing
The vibration of bearings is highly sensitive to damage to the bearings. For instance, phenomena such as peeling, indentation, rusting, cracks, and wear will all be reflected in the measurement of bearing vibration. By using special bearing vibration measuring devices (such as frequency analyzers), the magnitude of the vibration can be measured. However, frequency analysis cannot determine the specific nature of the anomaly. The measured values vary depending on the operating conditions of the bearings or the installation position of the sensors. Therefore, it is necessary to analyze and compare the measurement values of each machine in advance to determine the judgment criteria.