How to check the fault of double row cylindrical roller bearings?

In order to make the double row cylindrical roller bearings maintain their proper performance under good conditions and use them for a long time, the double row cylindrical roller bearings must be checked and maintained. Check cylindrical roller bearings for rolling noise, vibration, temperature and lubricant.

When the performance index of the double row cylindrical roller bearing is lower than the usage requirements and cannot work normally, the double row cylindrical roller bearing fails or even fails. Once the double row cylindrical roller bearing fails and other unexpected situations, the machine and equipment will stop. It is necessary to find out the cause of the occurrence in a short period of time and take corresponding measures.

1. Rolling sound of double row cylindrical roller bearings

The noise of double row cylindrical roller bearings is generated by the cylindrical roller bearing itself, that is, the inherent noise of the cylindrical roller bearing; the other is the noise generated after the double row cylindrical roller bearings is installed, which has nothing to do with the noise of the cylindrical roller bearing itself. Some problems can be analyzed by listening to the sound.

a) Noise related to the manufacture of double row cylindrical roller bearings: here includes cage noise and vibrato, cage noise mainly occurs in ball cylindrical roller bearings and tapered roller cylindrical roller bearings, when the cylindrical roller bearings rotate due to The vibration of the cage and the collision between the cage and the rolling elements will produce sound, which is periodic. Tremolo is a sound with a certain frequency, which is produced by the vibration caused by the large waviness on the raceway surface.

b) Inherent noise: Raceway sound: The raceway sound is produced by the elastic characteristics of the rolling elements when they are in contact with the raceway. When the double row cylindrical roller bearings rotates, the rolling elements roll on the raceway and emit a continuous and smooth sound. Sound; abnormal rolling friction sound can make uncomfortable abnormal metal friction sound such as "squeak, squeak", which will not be made when lubricated well. Therefore, it is not a problem in general, and it is only necessary to pay attention after the noise increases.

c) Noise caused by improper use: it exists for all kinds of cylindrical roller bearings. When the surface of the raceway or rolling element of the cylindrical roller bearing is bumped, cratered, and corroded, noise and vibration with a certain period will be generated. When the cylindrical roller bearing has dust intrusion during operation, it will generate dirt noise. This noise is aperiodic, and it is also accompanied by vibration. The sound level is not fixed and sometimes absent.

2. Vibration of double row cylindrical roller bearings

Vibration of double row cylindrical roller bearings has a significant effect on the failure of cylindrical roller bearings. For example, peeling, indentation, rust, cracks, wear, etc. will be reflected in the vibration detection of cylindrical roller bearings, so by using a special cylindrical roller bearing vibration measuring device, the magnitude of the vibration can be measured, and the frequency distribution can be inferred. For the specific situation of abnormal vibration, the measured value varies depending on the conditions of use of the cylindrical roller bearing or the installation position of the sensor. Therefore, it is necessary to analyze and compare the measured values ​​of each machine in advance to determine the judgment standard.

3. Temperature of double row cylindrical roller bearings

Usually, the temperature of cylindrical roller bearings gradually increases with the start of operation, and reaches a stable state after 1 to 2 hours. The normal temperature of cylindrical roller bearings varies with the heat capacity, heat dissipation, speed and load of the machine; if lubricated, installed If it is not suitable, the temperature of the cylindrical roller bearing will rise sharply, and abnormally high temperature will occur. At this time, the machine must be stopped and necessary preventive measures must be taken.

4. Lubricant

Lubrication has an important influence on the friction and wear, temperature rise and vibration of rolling cylindrical roller bearings. Without normal lubrication, cylindrical roller bearings cannot work. Analysis of the damage causes of cylindrical roller bearings shows that about 40% of cylindrical roller bearing damages are related to poor lubrication, so good lubrication of cylindrical roller bearings is an effective measure to reduce friction and wear of cylindrical roller bearings; In addition, the lubrication of cylindrical roller bearings also plays a role in heat dissipation, rust prevention, sealing, and shock mitigation. To ensure that the lubricant cannot expire and fail, the selection must be correct.

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