Generally speaking, the rolling bearing itself does not produce noise. The “bearing noise” usually felt is actually the sound effect of vibration between the bearing and the surrounding structure directly or indirectly. This is why many times noise problems can be regarded as vibration problems involving the whole bearing application.
1) Excitation caused by the change of the number of loaded rolling Bearing Noise elements: when a radial load is loaded on a bearing, the number of loaded rolling elements will change slightly during operation, which causes the deviation of the load direction. The resulting vibration is inevitable, but the vibration can be reduced by axial preloading.
(2) Local damage: a small number of bearing raceways and rolling Bearing Noise elements may be damaged due to incorrect operation or installation. During operation, damaged bearing components will produce specific vibration frequencies.
Vibration frequency analysis can identify damaged bearing Bearing Noise components. This principle has been applied to condition monitoring equipment to detect bearing damage.
(3) Accuracy of relevant parts: when the bearing ring is closely matched with the bearing seat or transmission shaft, the bearing ring may be Bearing Noise deformed by matching with the shape of adjacent parts. If deformation occurs, vibration may occur during operation.
(4) Pollutants: if operating in a polluted environment, impurities may enter the bearing and be rolled by the rolling element. The vibration degree depends on the quantity, size and Bearing Noise composition of the impurity particles being rolled. Although the typical frequency form will not be generated, a disturbing noise can be heard.
One is the wear of the mating surfaces of the inner and outer rings of the bearing. Due to this wear, the matching relationship between the bearing and the shell, the bearing and the shaft is damaged, resulting in the axis deviation from the correct position, and the bearing produces abnormal noise when moving at high speed.
When the bearing is tired, 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, dry friction and bearing breakage will produce abnormal sound. After the bearing is worn, the cage is loose and damaged, which will also produce abnormal noise.
In case of bearing failure in mechanical equipment, when disassembling the bearing for maintenance, record the appearance of the bearing, check the residual amount of lubricant in the bearing, sample and save the lubricant, and select kerosene or gasoline to simply clean the bearing.
Clean the disassembled bearing, first conduct rough cleaning, and then conduct fine cleaning. Place the bearing on the container and place the metal mesh as the bottom to prevent the bearing from directly removing the dirt at the bottom of the container.
During rough cleaning, the bearing shall not rotate with dirt to avoid damaging the rolling surface of the bearing. After removing the adhesive and grease with a brush, enter the fine washing step. Place the bearing in the cleaning oil and clean it while rotating. When the cleaning oil is dirty, replace it in time to ensure the fine cleaning effect.
In order to judge that the disassembled bearing can continue to be used, it is necessary to check after bearing cleaning. The inspection items of the bearing include: bearing foreign matters, bearing clearance, bearing dimensional accuracy, bearing frame wear, mating surface status, rolling surface status, raceway surface status, ball or roller operation status, etc.
For non separable small ball bearings, use one hand to level the inner ring of the bearing, and confirm whether the bearing can run smoothly by rotating the outer ring. For round cone roller bearings, the raceway surface and rolling element of the outer ring shall be inspected.