To solve the vibration problem of the motor must be to the point

Like all other machinery and equipment, motors have the transfer and change of various physical and chemical parameters such as energy, heat, wear, and vibration during the operation process. These changes in information directly and indirectly reflect the operation status of the motor, and vibration can sensitively reflect the operation status of the motor. There are many factors that cause motor vibration, including the quality problem of the motor itself, the matching problem between the motor and the equipment, and the actual operating conditions, etc.

As for the motor body itself, by controlling aspects such as the processing of components, the fixation of the windings, the dynamic balance of the rotor, and the fitting of components, it can be ensured that the inherent mechanical vibration characteristics of the motor meet the requirements. In addition to the vibration caused by mechanical factors, the vibration caused by electrical reasons is also relatively common. For example, the vibration caused by uneven air gaps between the stator and the rotor, the axial movement caused by the misalignment of the stator and rotor iron cores, the resonance caused by the power frequency, and so on. The analysis of the vibration caused by electrical factors can be directly judged by cutting off the power supply.

It is particularly important to note that different operating conditions have different requirements for the vibration of the motor, and thus special requirements need to be put forward for the overall strength of the motor. Therefore, full communication between the supplier and the buyer is of great significance.

Analysis of the causes of motor vibration:
● Caused by the imbalance of the rotor, coupler, shaft coupling, and driving wheel.
● The looseness of the iron core support, the failure and looseness of the oblique keys and pins, the loose binding of the wound rotor, and the poor balance of the rotor, etc., result in the imbalance of the rotating part.
● The misalignment of the object system in the linkage part, the non-coincidence of the center lines, and the incorrect centering. The main reasons for this kind of fault are the poor alignment and improper installation during the installation process.
● The center lines of the linkage part coincide when it is in the cold state, but after running for a period of time, vibration occurs due to reasons such as the deformation of the rotor supports, the foundation, etc., and the destruction of the center lines.
● There are faults in the gears and shaft couplings connected to the motor. Poor gear meshing, severe gear tooth wear, the skew and misalignment of the shaft coupling, incorrect tooth shape and pitch of the gear coupling, excessive clearance or severe wear will all cause certain vibration.
● The defects in the structure of the motor itself, such as the oval journal, the bent shaft, the excessive or too small clearance between the shaft and the bearing bush, and the insufficient stiffness of a certain part of the bearing seat, the base plate, the foundation, or even the entire motor installation foundation.
● The motor is not firmly fixed to the base plate, the anchor bolts are loose, and the bearing seat is loose from the base plate, etc.
● The excessive or too small clearance between the shaft and the bearing bush can not only cause vibration but also lead to abnormal lubrication and temperature of the bearing bush.
● The vibration is transmitted from the load driven by the motor. For example, the vibration of the fan and water pump driven by the motor causes the motor to vibrate.
● The wrong wiring of the stator of the AC motor, the short circuit of the rotor winding of the wound-type asynchronous motor, the inter-turn short circuit of the excitation winding of the synchronous motor, the wrong connection of the excitation coil of the synchronous motor, the broken bars of the rotor of the cage-type asynchronous motor, and the deformation of the rotor iron core resulting in uneven air gaps between the stator and the rotor, which leads to the imbalance of the air gap magnetic flux and thus causes vibration.