The noise of the bearing is determined by the bearing structure itself, called Essential noise which can be divided into three types: raceway sound, rolling element impact sound, and rolling sound.

China Stainless steel bearing expert ,BoYang Bearing leads you to acknowlege one of the essential noise ----Raceway Sound 

Bearing raceway sound and its control method Raceway sound is a slippery and continuous sound produced by rolling elements on the raceway surface when the bearing is running. It is a unique basic sound that occurs in all rolling bearings. The general bearing sound is the raceway sound plus other sounds. The raceway sound of a ball bearing is irregular, the frequency is above 1000Hz, its main frequency does not change with the speed, but its total sound pressure level increases with the speed of the speed. For bearings with loud raceway sound, the sound pressure level of the raceway sound decreases with the increase of viscosity; while for bearings with low raceway sound, the sound pressure level of the bearing with low raceway sound changes from a decrease when the viscosity increases to more than about 20mm2/s. To have increased. 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 and main frequency of the raceway sound will increase sharply as the radial clearance decreases. The methods to control the raceway sound are: select low-noise bearings, that is, bearings with small waviness, and carefully select the conditions of use. The noise of the raceway often affects the noise of the entire machine, reducing the noise of the raceway can reduce the noise of the entire machine.