Bearing vibration in general, the rolling bearing itself does not produce noise. The "bearing noise" that is usually felt is in fact a sound effect in which the bearing directly or indirectly vibrates with the surrounding structure. This is why many times the noise problem can be seen as affecting the vibration of the entire bearing application.
(1) Excitation caused by the change in the number of rolling elements loaded: When a radial load is applied to a bearing, the number of rolling elements carrying the load will change slightly during operation, which causes the load direction offset The The resulting vibration is unavoidable but can be relieved by axial preloading and applied to all rolling elements (not for cylindrical roller bearings).
(2) local damage: due to operation or installation errors, a small part of the bearing raceway and rolling body may be damaged. In operation, rolling through the damaged bearing parts will produce a specific vibration frequency. Vibration frequency analysis can identify damaged bearing parts. This principle has been applied to condition monitoring equipment to detect bearing damage. To calculate the bearing frequency, see Calculating the program "Bearing frequency".
(3) Accuracy of the relevant parts: In the case where the bearing ring is in close contact with the bearing seat or the drive shaft, the bearing ring may be deformed in accordance with the outer shape of the adjacent part. If a deformation occurs, vibration may occur during operation.
(4) Contaminants: If operated in a polluted environment, impurities may enter the bearing and be rolled by rolling elements. The degree of vibration generated depends on the number, size and composition of the imprinted impurity particles, although a typical frequency form does not occur, but a disturbing noise can be heard.
Rolling bearing noise causes more complex, one is the bearing, the outer ring with the surface wear. As a result of this wear and tear, damage the bearing and shell, bearing and shaft with the relationship, resulting in the axis deviation from the correct position in the shaft at high speed movement abnormal sound. When the bearing fatigue, the surface of the metal peeling off, but also the bearing radial clearance increased abnormal sound. In addition, the bearing lubrication is insufficient, the formation of dry friction, and bearing broken, etc. will produce abnormal sound. Bearing wear loose, the cage loose damage, will produce abnormal sound.