The culprit of bearing noise


In general, the vibration in the bearing, the rolling b […]

In general, the vibration in the bearing, the rolling bearing itself does not produce noise, and the usual "bearing noise" is actually the sound effect of the bearing directly or indirectly vibrating with the surrounding structure. This is why many times noise problems can be considered as vibration problems involving the entire bearing application. When a radial load is applied to a bearing, the number of rolling elements carrying the load changes slightly during operation, which causes a shift in the load direction. The resulting vibration is unavoidable, but can be mitigated by axial preloading and applied to all rolling elements (not for cylindrical roller bearings).
Small parts of the bearing raceways and rolling elements may be damaged due to handling or installation errors. In operation, rolling a damaged bearing component produces a specific vibration frequency. Vibration frequency analysis identifies damaged bearing components. This principle has been applied to condition monitoring equipment to detect bearing damage. To calculate the bearing frequency, please refer to the calculation program "bearing frequency".
In the case of a tight fit between the bearing ring and the bearing housing or the drive shaft, the bearing ring may be deformed in accordance with the shape of the adjacent member. If deformation occurs, vibration may occur during operation.
If operating in a polluted environment, impurities may enter the bearing and be crushed by the rolling elements. The degree of vibration generated depends on the amount, size and composition of the particles being crushed, although it does not produce a typical frequency form, but an irritating noise can be heard.
The causes of noise generated by rolling bearings are more complicated. One is the wear of the inner and outer rings of the bearing. Due to this wear, the bearing and the housing, the bearing and the shaft are broken, resulting in the axis deviating from the correct position and generating an abnormal sound when the shaft is moving at a high speed. When the bearing is fatigued, the surface metal peeling off will also increase the radial clearance of the bearing to produce abnormal noise. In addition, insufficient bearing lubrication, dry friction, and bearing crushing can produce abnormal sounds. After the bearing wears loose, the cage is loose and damaged, and abnormal noise is also generated.