Reasons for Abnormal Noise for Rolling Bearing

Aug 20, 2021

Rolling bearings are precision products, and generally, there will be no abnormal noise during use. However, some customers will find abnormal noise in the bearing during actual use, so they worry about whether the quality of the bearing is not good. There are many reasons for the abnormal noise of the bearing. Today we will analyze it.

Excited vibration due to changes in the number of rolling elements: When a radial load is applied to a certain bearing, the number of rolling elements carrying the load will slightly change during operation, causing the deviation of the load direction. The resulting vibration is unavoidable, but it can be reduced by axial preloading, which is loaded on all rolling elements. This method is not suitable for cylindrical roller bearings.

Partial damage: due to the operation or installation errors, a small part of the bearing raceways and rolling elements may be damaged. In operation, damaged bearing components will produce specific vibration frequencies; vibration frequency analysis can identify damaged bearing components. This principle has been applied to condition monitoring equipment to monitor bearing damage.

Accuracy of related parts: In the case of close cooperation between the inner and outer rings of the bearing and the bearing seat or the transmission shaft, the inner and outer rings of the bearing may be deformed due to improper fit with the adjacent parts. If deformation occurs, vibration may occur during operation.

Contaminants: If the equipment is operated in a polluted environment, impurities may enter the rolling bearing and be crushed by the rolling elements. The degree of vibration generated depends on the number, size, and composition of foreign objects. Although this situation does not produce a typical frequency pattern, a disturbing noise can be heard.

Others: Wear on the mating surfaces of the inner and outer rings of the rolling bearing. Due to this wear, the matching relationship between the bearing and the housing, the bearing and the shaft is destroyed, and the axis deviates from the correct position. The shaft produces abnormal noise when it is moving at high speed. When the bearing is fatigued, the metal on its surface will peel off, which will also increase the radial clearance of the bearing and produce abnormal noise. In addition, insufficient bearing lubrication, formation of dry friction, and bearing breakage will cause abnormal noise. Abnormal noise can also be caused by bearing wear and cage loosening and damage.

Therefore, the user must find out the cause of the abnormal noise and then adopt the corresponding solution.