Inspection of rolling bearings

Inspection and troubleshooting of water pumps during operation: The main items for inspection during operation include the rolling sound of the bearings, vibration, temperature, and the condition of lubrication. The details are as follows: When abnormal conditions are detected during operation, 1. Rolling sound of bearings – A sound level meter is used to examine the volume and quality of the rolling sound of the bearings while they are in operation; even minor damage such as slight stripping can cause abnormal sounds and irregular noises, which can be detected using a listening rod. 2. Bearing vibration: Bearing vibration is highly sensitive to damage to the bearings; issues such as flaking, indentation, rusting, cracks, and wear all show up in measurements of bearing vibration. Therefore, by using special devices for measuring bearing vibration (such as frequency analyzers), it is possible to determine the magnitude of the vibration, and frequency analysis can be used to identify the specific nature of any abnormalities. The measured values vary depending on the operating conditions of the bearings or the installation location of the sensors, etc.; therefore, it is necessary to analyze and compare the measurement values for each machine in advance in order to establish judgment criteria. 3. Bearing temperature: The bearing temperature can generally be estimated from the temperature outside the bearing housing; it would be more appropriate if the temperature of the outer ring of the bearing could be measured directly through the oil holes. Typically, the temperature of the bearing rises gradually as operation begins, and it reaches a stable level after 1-2 hours. The normal temperature of a bearing varies depending on the machine’s heat capacity, heat dissipation rate, speed, and load. If the lubrication and mounting are inadequate, the bearing temperature will rise sharply, resulting in abnormally high temperatures; in such cases, operation must be stopped and necessary preventive measures taken. 4. The role of bearing lubrication Lubrication has a significant impact on the fatigue life of rolling bearings, as well as on factors such as friction, wear, temperature rise, and vibration. Without proper lubrication, bearings cannot function. An analysis of the causes of bearing damage shows that about 40% of such damages are related to poor lubrication. Therefore, proper lubrication of bearings is an effective measure to reduce bearing friction and wear. In addition to that, bearing lubrication also serves multiple functions such as heat dissipation, rust prevention, sealing, and shock absorption.

Inspection of rolling bearings: 1. The surfaces of the rolling elements and raceways must not have spots, holes, dents, peeling, or similar defects； 2. It should rotate smoothly; when turned by hand, it must stop gradually without any sudden stops or vibrations ； 3. There should be a certain gap between the separator frame and the inner and outer rings; the separator frame can be pushed radially by hand to conduct a test ； 4. The clearance is within acceptable limits and meets the requirements.