With the continuous improvement of people's living standards, noise control of motors has become an indispensable and important technology for reducing the noise of deep groove ball bearings, especially for motors operating in residential environments, where the requirements are even more stringent.
1. To effectively control noise by solving rotor mechanical imbalance, the amount of rotor imbalance should be minimized as much as possible, otherwise the balance accuracy will be low. The balance accuracy is related to the specifications, properties, and usage conditions of the motor. The larger the ratio of the diameter to the length of the rotor core, the greater the centrifugal force and the higher the balance accuracy. The higher the speed of the rotor, the higher the requirement for balance accuracy. The basic condition of the motor during use, such as the stiffness difference between the bearings and various supporting parts, requires high balance accuracy.
2. The methods for reducing bearing noise can mainly be approached from the following aspects
(1) Pay attention to the selection of bearings. During the operation of most motor bearings, the vibration level of the bearings increases with the increase of the bearing inner diameter. For every 5mm increase in diameter, the vibration increases by about 1-2dB.
(2) Pay attention to the size of the radial clearance of the bearing. Excessive radial clearance can cause an increase in low-frequency noise, while insufficient clearance can cause an increase in high-frequency noise. In order to reduce the vibration and noise during bearing rotation, it is advisable to control the radial working clearance of the bearing within the range of 1-9 μ m
(3) Apply moderate pressure to the bearings. Its purpose is to eliminate the axial clearance of the rotor. Usually, waveform spring washers or three-point elastic washers can be used and placed at the shaft extension end.
(4) For motors with high noise requirements, silent bearings should be selected. When the load is small, oil containing sliding bearings can be used, and their noise is usually about 10dB lower than rolling bearings of the same size.
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