The reasons of Bearing Cage Noise and Preventive Measures

Sep 13, 2023

1. Bearing cage noise

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

This noise can occur in various bearings, but the sound pressure level is low and frequency.

Its characteristics are:

(1) This noise may be generated, Whether a stamping or plastic cage. 

(2) This noise will appear regardless of whether it is thin oil or grease lubrication. 

(3) The noise will most likely appear When the outer ring bears the bending moment. 

(4) This noise will likely appear When the radial clearance is large.

Since the clearance between the cage pocket and the clearance between the cage and the ring inevitably exists in the finished bearing, it is very difficult to eliminate the noise of the cage. Still, it can be improved by reducing the assembly error, optimizing the reasonable clearance, and improving the movement of the cage.

Another special sound of the cage is the noise caused by the self-excited vibration of the cage caused by the friction between the cage and the guiding surface of other bearing parts. The bearing's thin stamping cage produces low bending stiffness and instability during high-speed rotation. It will generate self-excited vibration due to bending deformation, causing "buzzing."

When the bearing is under the action of a radial load and the performance of the grease is poor, the noise of "click, click" will be heard at the beginning of the operation. It is mainly due to the sudden acceleration of the rolling body after leaving the load zone and the collision with the cage, resulting in noise. This kind of impact sound is inevitable, but its sound will gradually disappear as the running time increases.

2. The method to solve the noise of the bearing due to improper lubricant

There are occasions when bearings make noise due to improper use of lubricants. There are three solutions:

(1) Choose the correct lubricant;

(2) Add lubricant according to the specified amount of lubrication;

(3) Regularly replace the lubricant to avoid aging and hardening of the lubricant.

Don't worry too much if the bearings are making noise due to improper lubricant, as this problem can be effectively solved. If the bearing surface is damaged and dust enters, there is no need to worry because there are corresponding solutions.

3. Bearing cleaning

Cleaning is also very important to prevent the bearing cage's noise. First, the bearing must be removed for inspection, and its appearance must be 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, non-aqueous diesel or kerosene is usually used as a cleaning agent and is often filtered to keep it clean. After cleaning, anti-rust oil or grease should be applied to the bearing surface immediately to avoid oxidative corrosion.

4. Inspection and Judgment

When deciding whether a disassembled bearing can be reused, verifying its dimensional accuracy, rotation accuracy, internal clearance, mating surface, raceway surface, cage, and sealing ring is essential. The inspection results can be assessed by individuals who understand bearings well or are well-versed in bearing technology. Judgment criteria may vary depending on mechanical properties, criticality, inspection cycle, etc.

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

(1) The bearing parts are broken and defective. 

(2) The raceway surface and the rolling surface are peeled off.

After all, when judging whether the bearing can continue to be used, it is necessary to conduct a comprehensive inspection and evaluation and judge according to relevant standards. If the above damage occurs, the bearing must be replaced at once to ensure the safe operation of the machine equipment.

FV Bearing has a strong team of technical engineers to solve your pre-sale doubts and provide perfect after-sales service. We provide you with best solution.