How can we make the bearing run quietly?

Noise in bearings is generally caused by a variety of factors, but basically all of the factors are related to vibration. We analyze how bearing vibration and noise levels are affected by bearing manufacturing, tolerance fit and lubricant selection.

Bearing rings and rolling parts are not perfectly round, and even after a lot of fine grinding and polishing, the rolling parts and raceways can never be completely smooth. These defects can cause unnecessary vibration, which can damage the bearing during its service life.

Rough or damaged rolling element or raceway, poor ball or raceway roundness, internal bearing contamination, inadequate lubrication, improper shaft or bearing seat tolerances, and improper radial clearance can all cause bearing vibration, which can lead to excessive noise.

1. Bearing manufacturing impact on sound

Quiet bearings with excellent surface finish on ball and raceway. In the manufacturing process, the roundness of the ball and bearing rings will be strictly controlled. The smoothness or quietness of the bearing can be detected by an accelerometer that measures bearing vibration at the outer ring, which generally rotates at a speed of 1800rpm.

Another way to control noise is to set the radial clearance so that the bearing has almost zero radial clearance when in use. If the shaft or housing tolerance is wrong, the bearing may be too tight, which will cause excessive noise. Similarly, the roundness of the shaft or bearing seat will deform the bearing ring, which will affect the vibration and noise of the bearing.

2. Impact of bearing tolerance on sound

Bearing fit is another important factor to consider. Poor matching practices can lead to bearing raceway dents, which greatly increases vibration. Similarly, pollutants in bearings can also cause unnecessary vibration.

3. The effect of lubricant on sound

In order to remain silent, bearings must be free of contaminants. If the bearing is not used in a very clean environment, dust protection, such as contact seals, should be considered.

In high quality bearings, the use of silent lubricants is also recommended. These finely filtered greases will allow the bearing to run quietly because there are no large solid particles.