Compared with low-voltage motors, high-voltage motors, especially high-voltage asynchronous motors, are mostly based on cage rotor structure. During motor manufacturing and operation, due to inappropriate coordination of mechanical structural parts, it may lead to serious vibration of the motor, which may be radial vibration or axial vibration.
The uneven air gap between stator and rotor is the key factor of motor vibration. In the process of production and processing, when the motor frame, stator core and rotor part are not coaxial, it will directly lead to the uneven air gap of the motor, and after the motor is energized, it will cause electromagnetic vibration of the motor because of the unilateral magnetic tension, which causes vibration, in addition to mechanical vibration, but also accompanied by low-frequency electromagnetic sound. For the motor in operation, especially the motor after repair, due to the long-term operation, the motor bearing, bearing chamber, bearing diameter may occur some dimensional deviation, resulting in unreasonable coordination between each other, resulting in motor vibration problems. For the matching parts of the bearing inner and outer rings, when there is a serious loosening problem, the fatal quality failure of the bearing will occur in a short time because of the bearing running ring and the bearing will heat up until it is burned.
For the rotor part of the motor, due to the deformation of the rotor guide bar and the failure of the original balance state during the operation of the motor, the rotor body is out of balance, which is a common fault cause in the operation of high and low voltage motors. For high-voltage motors, especially those with sliding bearings, the misalignment of the magnetic center line is the fundamental cause of axial vibration of the motor, which is the key to good control during the installation and use of high-voltage motors. In order to prevent similar problems, starting process control is particularly important for cage high-voltage motors to prevent motor starting difficulties caused by insufficient power supply capacity.
In the analysis and inspection of motor vibration problems, the necessary item inspection should be carried out to find out the root cause of vibration. Some motor repair units, more inclined to replace the bearing, objectively speaking, the bearing does not meet the motor vibration problem, but the bearing does not necessarily solve the motor vibration problem, so the in-depth comprehensive analysis is more conducive to the solution of the problem. For electromagnetic reasons, the asymmetry of the winding and the electrical quality failure of the winding will lead to the uneven magnetic field of the motor, which will also lead to the electromagnetic vibration of the motor, which is more manifested as violent jitter accompanied by serious dull sound, and mechanical vibration is still different, and can be clearly distinguished in the analysis process.
Post time: Mar-04-2025