Generally speaking, rolling bearings themselves do not generate noise. The bearing noise that is usually felt is actually the sound effect of the bearing directly or indirectly vibrating with the surrounding structure. This is why many time...
Generally speaking, rolling bearings themselves do not generate noise. The “bearing noise” that is usually felt is actually the sound effect of the bearing directly or indirectly vibrating with the surrounding structure. This is why many times the noise problem can be regarded as a vibration problem involving the entire bearing application.
1.Excited vibration due to changes in the number of loaded rolling elements: When a radial load is loaded on a certain bearing, the number of rolling elements carrying the load will slightly change during operation, which causes 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 (not applicable to cylindrical roller bearings).
2.Partial damage: due to operation or installation errors, a small part of the bearing raceways and rolling elements may be damaged. In operation, rolling over 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 detect bearing damage. To calculate the bearing frequency, please refer to the calculation program "Bearing Frequency".
3.Accuracy of related parts: In the case of a close fit between the bearing ring and the bearing seat or drive shaft, the bearing ring may be deformed by matching the shape of the adjacent part. If deformation occurs, vibration may occur during operation.
4.Contaminants: If running in a polluted environment, impurities may enter the bearing and be crushed by the rolling elements. The degree of vibration produced depends on the number, size and composition of the crushed impurity particles. Although it does not produce a typical frequency form, a disturbing noise can be heard.
The causes of noise produced by rolling bearings are more complicated. One is the wear of the mating surfaces of the inner and outer rings of the bearing. Due to this kind of wear, the matching relationship between the bearing and the housing, and the bearing and the shaft is destroyed, causing the axis to deviate from the correct position, and abnormal noise occurs when the shaft 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. After the bearing is worn and loosened, the cage is loosened and damaged, and abnormal noise will also be produced.