Motor bearing is an important part of the motor, and its performance and state directly affect the running stability and service life of the motor. The vibration monitoring and fault diagnosis of motor bearing can find the potential trouble in time, avoid the occurrence of failure or reduce the impact of failure. In this paper, the vibration monitoring and fault diagnosis of motor bearings are introduced and analyzed in detail, so that readers can have a reference in practical application.
The main function of the motor bearing is to support the rotor, reduce the friction between the rotor and the stator, and ensure the normal operation of the motor. There are many types of motor bearings, such as deep groove ball bearings, cylindrical roller bearings, angular contact ball bearings, etc. Different kinds of bearings have different structures and characteristics, and need to be selected according to the specific situation.
Vibration monitoring is an effective method for motor bearing fault diagnosis. By collecting and analyzing the bearing vibration signal, the working state and fault type of the bearing can be judged. The following are the basic steps of motor bearing vibration monitoring:
Select the right vibration sensor: according to the specific situation of the motor, select the right vibration sensor for vibration signal acquisition. In general, the acceleration sensor is suitable for the acquisition of low-frequency vibration signals, the speed sensor is suitable for the acquisition of mid-frequency vibration signals, and the displacement sensor is suitable for the acquisition of high-frequency vibration signals.
Set monitoring parameters: according to the specific situation of the motor and monitoring requirements, set the appropriate monitoring parameters, such as sampling frequency, measurement range, etc.
Vibration signal acquisition: the vibration sensor is installed in the appropriate position of the motor to collect the vibration signal of the bearing. In the process of acquisition, attention should be paid to avoid the influence of external interference and noise.
Analysis of vibration signals: The collected vibration signals are analyzed and processed to extract useful characteristic information. The commonly used analysis methods are time domain analysis, frequency domain analysis, envelope analysis and so on.
Judging the bearing status: judging the working status and fault type of the bearing according to the analysis results. Generally speaking, the vibration signal of normal bearings has a stable amplitude and frequency, while the vibration signal of faulty bearings will have an abnormal amplitude and frequency.
Fault diagnosis is to judge and identify the fault type and cause of the motor bearing according to the monitoring results and analysis results. The following is the basic method of motor bearing fault diagnosis:
Auscultation: Determine the working state of the bearing by listening to the sound of the bearing during operation. The sound is crisp and uniform when the normal bearing is running, while the faulty bearing will emit abnormal noise and abnormal noise.
Observation method: By observing the appearance and operation of the bearing, judge the working state of the bearing. Normal bearings have smooth appearance and no wear, while faulty bearings will have abnormal conditions such as wear, rust, and discoloration.
Olfactory method: Sense the smell of the bearing when it is running, and judge the working state of the bearing. There is no obvious odor when the normal bearing is running, while the faulty bearing will emit abnormal odor such as burning and metal friction.
Instrument diagnosis method: Through the professional fault diagnosis instrument to diagnose the bearing, judge the working state of the bearing and the type of fault. Commonly used fault diagnosis instruments are vibration analyzer, acoustic emission detector and so on.
Comprehensive analysis method: comprehensive use of the above methods for fault diagnosis, combined with the actual situation for analysis and judgment, to obtain accurate diagnosis results.
Taking a certain type of motor as an example, abnormal vibration and noise occur during the operation of the motor, and it is suspected that there is a fault in the bearing. Through the vibration monitoring and fault diagnosis of the motor, it is found that the front bearing of the motor is wearing and loosening. In response to the fault, measures were taken to replace the front bearing, and other bearings were inspected and maintained. After treatment, the vibration and noise of the motor return to normal, and the running stability is improved.
This paper introduces the methods and steps of vibration monitoring and fault diagnosis of motor bearing, and analyzes the cases in practical application. Through the vibration monitoring and fault diagnosis of motor bearing, the potential trouble can be found in time to avoid the occurrence of failure or reduce the impact of failure. In practical application, it is necessary to choose the appropriate monitoring method and diagnosis method according to the specific situation, and analyze and judge the actual situation to get the accurate diagnosis result. In the future, with the continuous development of science and technology, it is believed that more advanced monitoring technologies and diagnostic methods will appear to provide more reliable support for the maintenance and maintenance of motor bearings.
