When the imported bearing rotates, the free vibration of the cage and its impact with the rolling elements or rings will cause noise.

This kind of noise may appear in various bearings, but the sound pressure level is low and it is low frequency. Its characteristics are:

       a. This noise may occur whether it is a stamped cage or a plastic cage.

       b. This noise will occur whether it is thin oil or grease lubrication.

       c. This noise is most likely to occur when the outer ring is subjected to bending moment.

       d. When the radial clearance is large, this noise is likely to occur.

Since cage pocket clearance and cage and ring clearance inevitably exist in finished bearings, it is very difficult to completely eliminate cage noise, but it can be improved by reducing assembly errors and optimizing reasonable clearance and cage movement.

Another kind of special cage sound is the noisy sound caused by the self-excited vibration of the cage caused by the friction between the cage and the guide surface of other bearing parts. The stamped cage of imported bearings is thin, has low bending stiffness in the radial and axial planes, and has poor overall stability. When the bearing rotates at high speed, it will produce self-excited vibration due to bending deformation, causing "buzzing".

When the bearing is under radial load and the grease performance is poor, a "clicking, clicking" noise will be heard in the early stages of operation. This is mainly due to the sudden acceleration of the rolling elements after leaving the load area and collision with the cage, resulting in noise. This knocking sound is unavoidable, but as the operating time increases, its sound will gradually disappear.

There are three ways to solve the problem of noise caused by improper lubricant in imported bearings:

Choose the right lubricant;

Add lubricant according to the specified lubrication amount;

Change the lubricant regularly to avoid aging and hardening of the lubricant.

If a bearing is making noise due to improper lubricant, don’t worry too much as this problem can be effectively solved. If the bearing surface is damaged and dust enters, don't worry, because there are corresponding solutions.

Clean:

First, the bearing needs to be disassembled for inspection and its appearance recorded. At the same time, determine the amount of lubricant remaining in the bearing and take a sample before cleaning the bearing.

Cleaning can be divided into two steps: rough cleaning and fine cleaning. Neutral water-free diesel or kerosene is usually used as a cleaning agent, and it is often filtered to keep it clean. After cleaning, anti-rust oil or anti-rust grease should be applied to the bearing surface immediately to avoid oxidative corrosion.

Inspection and Judgment:

In order to determine whether the disassembled imported bearing can be reused, special inspection is required to check its dimensional accuracy, rotation accuracy, internal clearance, as well as the mating surface, raceway surface, cage and sealing ring. The inspection results can be evaluated by a person familiar with bearings or knowledgeable about bearings. Judgment criteria may vary depending on mechanical performance, importance, inspection cycle, etc.

If the following damage occurs, the rolling bearing must be replaced and cannot be reused:

Imported bearing parts appear broken and defective.

The raceway surface and rolling surface are peeling off.

In short, when judging whether imported bearings can continue to be used, they need to be comprehensively inspected and evaluated, and judged in accordance with relevant standards. If the above damage occurs, the bearing must be replaced immediately to ensure the safe operation of the machine and equipment.