How to test the noise of thin section bearings?

The noise test method of Thin section bearings mainly includes the following steps:

‌Select the test environment‌: The test should be carried out in an anechoic chamber with good acoustic performance. The anechoic chamber can effectively absorb the incident sound waves, and the influence of the reflected sound waves on the sound field can be basically ignored, thus providing an environment close to the free sound field‌.

‌Measuring instrument‌: Use the A-weighted network sound pressure level for measurement. The A-weighted sound level is suitable for simulating the frequency characteristics of the human ear to low-intensity noise below 55dB, and has a greater degree of attenuation for low-frequency components‌.

‌Background noise requirements‌: The background noise should generally be lower than 15dB(A) or even 12dB(A), and the difference between the bearing noise and the background noise should be more than 10dB(A) to ensure measurement accuracy‌.

‌Causes of bearing noise and its test methods‌:

The causes of bearing noise are diverse, including but not limited to the following:

‌Contact and collision between the raceway and the rolling element‌: During the operation of the bearing, the contact and collision between the raceway and the rolling element will generate vibration, which will then be converted into sound‌. ‌Improper lubrication‌: Improper lubrication can cause the bearing to make a sharp sound‌.

‌Installation problem‌: The knock marks caused by installation can also produce noise‌.

‌Contaminants‌: Contaminants in the bearing can cause hissing sounds‌.

In terms of test methods, the method of monitoring vibration noise is usually adopted because vibration and noise are closely related. The source and nature of the noise can be identified by monitoring vibration‌.

‌Precautions‌:

When conducting bearing noise tests, the following points should be noted:

‌The influence of background noise‌: If the measured noise sound pressure level of the tested bearing is more than 10dB(A) greater than the background noise sound pressure level, the background noise can be ignored; otherwise, correction is required‌.

‌Test environment preparation‌: Ensure that the test environment meets the conditions of a free sound field to reduce measurement errors‌.

Through the above methods and precautions, the noise test of equal-section bearings can be effectively carried out to ensure the accuracy and reliability of the test results.