The generation of vibration in bearings Generally speaking, rolling bearings themselves do not produce noise.The “bearing noise” usually felt is in fact the sound effect of the vibration of the bearing directly or indirectly with the surrounding structure.

A. Excitation caused by the change of the number of loading rollers:

When a radial load is loaded on a bearing, the number of rollers carrying the load will change slightly during operation, which causes the offset of the load direction.The resulting vibration is unavoidable but can be mitigated by axial preloading on all rolling elements (not applicable to cylindrical roller bearings).

B.Local Damage:

Small parts of bearing raceways and rollers may be damaged due to handling or installation errors.In operation, rolling over a damaged bearing component will produce a specific vibration frequency.Damaged bearing parts can be identified by vibration frequency analysis.This principle has been used in condition monitoring equipment to detect bearing damage.To calculate the bearing frequency, see the calculation program “Bearing frequency”.

C.Accuracy of related parts:

In the case of close match between the bearing ring and the bearing seat or the drive shaft, the bearing ring may be deformed with the shape of the adjacent parts.If deformation occurs, vibration may occur during operation.

D.Contaminants:

If operating in a polluted environment, impurities may enter the bearing and be crushed by the rolling element.The degree of vibration produced depends on the number, size, and composition of the crushed impurity particles. Although it does not produce the typical frequency pattern, a disturbing noise can be heard.