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How to solve the vibration problem of motor?

Motors, like all other machines and equipment, undergo transmission and changes in various physical and chemical parameters such as energy, heat, wear, and vibration during operation. These information changes directly and indirectly reflect the operating status of the motor, and vibration is Can sensitively reflect the operating status of the motor. There are many factors that cause motor vibration, including the quality of the motor itself, the matching of the motor and equipment, and the actual working conditions of use, etc.


As far as the motor body is concerned, the processing of parts, the fixation of windings, the dynamic balance of the rotor, and the coordination of parts can be controlled to ensure that the inherent mechanical vibration characteristics of the motor meet the requirements. In addition to vibrations caused by mechanical factors, vibrations caused by electrical factors are also common, such as vibrations caused by uneven air gaps between the stator and rotor, axial movement caused by misalignment of the stator and rotor cores, resonance caused by power frequency, etc. wait. Vibration analysis caused by electrical factors may be directly judged by cutting off the power supply.

It is particularly important to remind that different operating conditions have different vibration requirements for the motor, which in turn requires special requirements for the overall strength of the motor. Therefore, full communication between the supply and demand parties is particularly important.


Analysis of causes of motor vibration:

●Caused by unevenness of the rotor, coupler, coupling and transmission wheel.

●The iron core bracket is loose, the tilt and pin failure are loose, the winding rotor is not tied tightly, the rotor is poorly balanced, etc., causing the rotating part to be unbalanced.

●The linkage parts are misaligned, the center lines do not coincide with each other, and the centering is incorrect. The main cause of this failure is poor alignment and improper installation during the installation process.

●The center lines of the linkage part are coincident in the cold state, but after running for a period of time, vibration occurs due to the deformation of the rotor fulcrum, its foundation, etc., and the destruction of the center line.

●The gears and couplings connected to the motor are faulty, the gears are poorly engaged, the gear teeth are severely worn, the couplings are skewed or misaligned, the tooth shape and pitch of the gear coupling are incorrect, the clearance is too large or the wear is severe, all of these problems will occur. Cause some vibration.

●Structure defects of the motor itself, such as elliptical journal, bent shaft, too large or too small gap between shaft and bearing, insufficient stiffness of bearing seat, base plate, certain parts of the foundation and even the entire motor installation foundation.

●The motor and the base plate are not firmly fixed, the foot bolts are loose, the bearing seat and the base plate are loose, etc.

●The gap between the shaft and the bearing bush is too large or too small, which can not only cause vibration but also cause abnormalities in the lubrication and temperature of the bearing bush.

●The load driven by the motor conducts vibration. For example, the fan or water pump driven by the motor vibrates, causing the motor to vibrate.

●AC motor stator wiring errors, winding asynchronous motor rotor winding short circuit, synchronous motor field winding inter-turn short circuit, synchronous motor field wire circle connection error, cage asynchronous motor rotor broken bars, rotor core deformation resulting in stator and rotor air gap misalignment uniformly, resulting in unbalanced air gap flux and resulting in vibration.