Case one: bearing raceway sound and control methods Raceway sound is when the bearing is running, the rolling body rolling on the rolling surface and issued a slippery continuous sound, all rolling bearings will occur unique to the basic sound . The general bearing sound is the rolling sound plus other sounds. Ball bearing roller sound is irregular, the frequency of more than 1000Hz, its main frequency does not vary with the speed, but its total sound pressure level increases with the speed increase. Rolling sound big bearings, the sound pressure level of its raceway sound decreases with the increase of viscosity; and the small raceway sound pressure, the sound pressure level in the viscosity increases to about 20mm2 / s or more, by reducing the turn To increase. The greater the rigidity of the bearing seat, the lower the total sound pressure level of the raceway sound. If the radial clearance is too small, the total sound pressure level of the raceway sound and the main frequency will increase sharply with the reduction of the radial clearance. The method of controlling the raceway sound is: Use low noise bearing that is a very small waviness bearings, carefully choose the conditions of use. Rolling often affect the noise of the entire machinery, reducing raceway noise can reduce the noise of the entire machinery. Scenario 2: Impact sound of rolling elements and its control method Larger models of ball bearings or cylindrical roller bearings operate under low speed with purely radial load. Due to the small centrifugal force of the rolling elements, the rolling elements in the non-load area will Impact cage or raceway and make noise. But with the speed increase, this sound will disappear. The rolling body impact sound control methods are: Appropriate to reduce the radial clearance, the use of a reasonable structure and the material has the flexibility of the cage bearing. Scenario 3: Rolling noise of bearings and how they are controlled Rolling noise is the harsh metal friction noise that can occur on cylindrical roller bearings on all occasions, mostly in larger grease lubricated bearings, whereas in base oil properties Degraded grease is more likely to occur and hardly occurs when oil is lubricated. In addition, it is easy to happen in winter and when it is subjected to pure radial load, it is easy to occur when the radial clearance is large, and it will occur easily in a specific speed range depending on the model size. Will appear intermittently. Outer ring raceway to take special processing methods to prevent the emergence of rolling sound, if necessary, choose this bearing, or appropriate to reduce the radial bearing clearance, the use of high performance grease and improve the rigidity of the bearing and matching parts .