[Bearing knowledge] The cause of bearing noise

The cause of bearing noise

　　1. Excitation caused by changes in the number of loaded rolling elements When a radial load is loaded on a bearing, the number of rolling elements bearing the load will change slightly during operation, causing the load direction to shift. 2. Local damage Due to operation or installation errors, a small part of the bearing raceway and rolling element may be damaged. During operation, damaged bearing components produce specific vibration frequencies. Vibration frequency analysis identifies damaged bearing components. This principle has been applied to condition monitoring equipment to monitor bearing damage. 3. The accuracy of the relevant parts in the case of close coordination between the bearing inner and outer rings and the bearing seat or the drive shaft, the bearing inner and outer rings may be improperly matched with the shape of the adjacent parts and deformed. If deformation occurs, vibration and noise may occur during operation. 4. Contaminants If the equipment is operated in a polluted environment, impurities may enter the bearing rolling body, resulting in vibration and sound. In this case, a disturbing noise can usually be heard. 5. The causes of noise generated by other rolling bearings are more complex, one is the wear of the inner and outer rings of the bearing. Due to this wear, the mating relationship between the bearing and the housing and the bearing and the shaft is destroyed, resulting in the axis deviating from the correct position. The shaft produces abnormal sound when moving at high speed.

　　In addition, insufficient lubrication of bearings, the formation of dry friction, and bearing breakage will produce abnormal sounds. Bearing wear, cage loose damage, will also produce abnormal noise.

Bearing different noise size is not the same?

　　1, the noise of ball bearings is lower than that of roller bearings, and the (friction) noise of bearings with less relative sliding is lower than that of bearings with more relative sliding; The number of balls is large, the outer ring is thick, and the noise is smaller; 2, the noise of the bearing using the solid cage is relatively lower than that of the bearing using the stamped cage; 3, the noise of the bearing using plastic cage is lower than that of the bearing using the above two cages; 4, high precision bearings, especially bearings with higher rolling precision, the noise is relatively small than the noise of low precision bearings; 5, the noise of small bearings is relatively small than that of large bearings.

　　Of course, this is the case in theory, and the size of the noise in practical applications is also influenced by many factors.