The essential noise of the bearing is the noise determined by the structure of the bearing itself, which will still occur even if the bearing is manufactured by modern processing technology. Intrinsic noise can be divided into three types: raceway sound, rolling body impact sound and rolling sound, which are described as follows: (1) Bearing raceway sound and its control method A slippery and continuous sound produced by rolling on the raceway surface is a unique basic sound that occurs in all rolling bearings. The general bearing sound is the raceway sound plus other sounds. The sound of the raceway of the ball bearing is irregular, and 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 noise, the sound pressure level of the raceway noise decreases with the increase of viscosity; while for bearings with low raceway noise, the sound pressure level of the bearing with the raceway noise increases from decrease to above 20mm2/s. for some increase.
The more rigid the bearing housing, the lower the total sound pressure level of the raceway noise. 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 noise of the raceway are: choose low-noise bearings, that is, bearings with small waviness, and carefully select the use conditions. The noise of the raceway often affects the noise of the whole machine, and reducing the noise of the raceway can reduce the noise of the whole machine. (2) Impact sound of rolling elements and its control method When larger ball bearings or cylindrical roller bearings operate at low speeds under pure radial loads, due to the small centrifugal force of rolling elements, the rolling elements in the non-load area will Noise due to impact on cage or raceway. But as the speed increases, this sound will disappear.
The control methods for the impact sound of the rolling elements include: appropriately reducing the radial clearance, and using a bearing with a cage with a reasonable structure and a flexible material. (3) The rolling sound of the bearing and its control method The rolling sound is the harsh metal friction sound that may occur in cylindrical roller bearings in all occasions, and most of them occur in larger grease-lubricated bearings. It is more likely to occur in deteriorated grease, and hardly occurs in oil lubrication. In addition, it is more likely to occur in winter. When bearing pure radial load, it is easy to occur in occasions with large radial clearance, and it is easy to occur in a specific speed range depending on the size of the model, and it will occur continuously. Happens intermittently. A special processing method for the raceway of the outer ring can prevent the appearance of rolling noise. If necessary, this kind of bearing can be selected, or the radial clearance of the bearing can be appropriately reduced, and the use of lubricating grease with excellent performance and the rigidity of the matching parts of the bearing can be improved. .
