Emergency measures for limit speed noise of cylindrical roller bearings

Writer： admin Time：2022-06-28

There are many reasons for the failure of cylindrical roller bearings. In addition to normal bearing fatigue spalling, factors such as failed seals, too small bearing clearance or poor lubrication caused by tight fit can leave special failure traces and failure forms. Therefore, checking the bearing failure can find the cause of the bearing failure in most of the time, so as to take corresponding measures in time to prevent it.

Generally speaking, 1/3 of the failure of the bearing is because the bearing has reached the fatigue spalling period, which is a normal failure; 1/3 is due to the poor lubrication of the bearing, which leads to early failure, and 1/3 is due to the contamination entering the outer spherical bearing or the incorrect installation, which causes the bearing to fail in advance. invalid. Generally speaking, there are seven common symptoms when the bearing is not running normally: the bearing is overheated, the bearing noise is too large, the bearing life is too low, the vibration is too large, the machine performance requirements cannot be met, the bearing is loose on the shaft, and the shaft is difficult to rotate.

The raceway sound of the bearing and its control method The raceway sound is a slippery and continuous sound emitted by the rolling elements rolling on the raceway surface when the second-class bearing is running. It is a unique basic sound that occurs in all rolling bearings. The general outer spherical bearing sound is the raceway sound plus other sounds. The raceway sound of the bearing is irregular, the frequency is above 1000Hz, its main frequency does not change with the rotation speed, but its total sound pressure level increases with the acceleration of the rotation speed. For bearings with loud raceway sound, the sound pressure level of the raceway sound decreases with the increase of viscosity; for the second-class bearings with small raceway sound, the sound pressure level of the bearings increases from about 20mm2/s to about 20mm2/s. And turned to increase. The more rigid the housing, the lower the total sound pressure level of the raceway sound. If the radial clearance is too small, the total sound pressure level and dominant frequency of the raceway sound will increase sharply with the reduction of the radial clearance. The methods of controlling the sound of the raceway are as follows: choose low-noise bearings, that is, bearings with small waviness, and carefully select the conditions of use. The sound of the raceway often affects the noise of the entire machine, and reducing the sound of the raceway can reduce the noise of the entire machine.

Impact sound of rolling elements and its control method, when larger type bearings or outer spherical bearings run at low speed under pure radial load, due to the small centrifugal force of rolling elements, the rolling elements in the non-load zone will impact the cage or The raceway makes noise. But as the revs increase, the noise disappears. The control methods for the impact sound of the rolling elements are: reducing the radial clearance appropriately, and using the second-class bearing with a cage with a reasonable structure and a flexible material.

Rolling sound of bearing and its control method Rolling sound is a harsh metal friction sound that may occur in bearings in all occasions. Most of them occur in larger types of bearings lubricated by grease, and are more likely to be used in greases with degraded base oil performance. Occurs, hardly occurs with oil lubrication. In addition, it is more likely to occur in winter. When subjected to pure radial load, it is prone to occur in occasions with large radial clearance, and it is prone to occur within a specific speed range depending on the size of the model, and it will occur continuously. Reappears intermittently. Adopting a special processing method for the outer ring raceway can prevent the occurrence of rolling noise. If necessary, this kind of outer spherical bearing can be used, or the radial clearance of the bearing can be appropriately reduced, the grease with excellent performance is used, and the matching parts of the bearing can be improved. rigidity.