Noise Characteristics and Countermeasures of Motor Bearings
Motor bearing noise is a main type of noise in the operation of motors. The unique noise characteristics of electrically excited bearing vibration have a great impact on the sound environment of operating venues, so the study of bearing noise characteristics and corresponding countermeasures has an important practical significance.
1 Noise Characteristics
The noise of motor bearing is mainly composed of two parts: impact sound and rolling element sound. The impact sound is caused by the periodic impact between the rolling elements and the inner and outer raceways of the bearing; the rolling element sound is caused by the bearing rolling fatigue, rolling body invasion and the impact between the rolling elements.
Under normal circumstances, the sound produced by motor bearing is periodic, with a clear frequency spectrum pattern. According to practical experience and experimental data, the low-frequency sound of motor bearing can be divided into three major frequency bands according to the sound pressure level. It is common for the sound pressure of bearing ring to form a peak at a certain frequency, which is called its resonance frequency. It is related to the bearing size and design parameters.
2 Causes of Bearing Noise
The main cause of bearing noise is the deterioration of bearing performance and quality.
(1) The design of bearing structure has errors, such as the inner and outer ring raceway size of the bearing, rolling elements size producing clearance, the force balance of rolling element group, the bearing loading condition, etc., which cause the bearing to vibrate abnormally and generate noise.
(2) Poor installation, improper mounting force during installation, load eccentricity, etc. affect the performance of bearing, resulting in damage and noise of bearing.
(3) Damage caused by poor lubrication, such as lack of lubricant, wrong lubricant, excessive lubricant, excessive filling temperature and excessive filling amount.
(4) Improper bearing working condition, such as incorrect lubrication,excessive speed, excessive and inadequate wobbels.
3 Countermeasures
(1) Improve the design of bearing structure: Properly adjust the bearing type, size and material selection, ensure that the bearing installation and usage meet the design requirements of the bearing.
(2) Improve the installation quality: Properly adjust the structure and installation of the bearing mounting parts, and determine the installation method and installation force of the bearing correctly.
(3) Pay attention to the bearing working conditions: Pay attention to bearing temperature and lubricant quality, regularly inspect and replace when necessary.
(4) The use of advanced anti-vibration and noise reduction technologies: Investigate and select appropriate noise reduction and anti-vibration measures to reduce bearing vibration and noise.
Through the study of noise characteristics and countermeasures of motor bearing, the maintenance and improvement of motor bearing can be effectively guaranteed, and the sound environment of motor operation can be improved.
