Permanent magnet synchronous motor stator and rotor assembly process

1. Customize the rotor assembly process plan

By using the knowledge of electromagnetics, since the stator and rotor are basically symmetrical circular structures, if the stator and rotor pass absolutely, then the axial centerlines of the stator and rotor will be completely coincident, so the electromagnetic attraction of the rotor to the stator basically does not exist. There will be no suction between the stator and the rotor, and the vertical stator and rotor of the motor can be assembled by the gravity of the rotor itself. The greater the deviation of the axial centerline of the stator and the rotor, the stronger the unilateral sub-pull between the stator and the rotor, and the rotors are easily biased towards one side to attract each other. Therefore, how to ensure accurate guidance in the combination of the stator and rotor to ensure the concentricity of the stator and rotor when the stator and rotor are combined is the main key to solve the problem of rotor attraction. 

In the process of assembling the stator and rotor, the resistance is generally greater than the gravity of the rotor itself, so the falling process of the rotor is affected by the relatively strong magnetic force between the stator and the rotor. The more the rotor falls, the more overlapping parts will be customized The more, the stronger the magnetic force will be, resulting in the tooling being easily deformed and twisted. Therefore, we can continuously enhance the bending resistance of the guide tooling, reduce the deflection of the rotor during the assembly process, and continuously increase the quality of the rotor by selecting the appropriate tolerance and material of the guide tooling. The suction force is effectively reduced. At the same time, it can also ensure that the gravity of the rotor itself can be greater than the resistance received by the rotor during the falling process. The stator and rotor are assembled by accurately positioning the guide device, and the rotor can be assembled by slowly falling under the action of its own gravity. 

2. Verification of the stator and rotor assembly process plan

The permanent magnet motor used in the experiment is a traction motor of an air rail vehicle. It mainly adopts a suspension structure. The volume of the motor is relatively small, but the structure is relatively mature. Most of the permanent magnet traction motors currently produced are solid. shaft, so this permanent magnet motor has a strong representation. The other motor is a permanent magnet synchronous direct drive traction motor, which adopts the structure of a hollow shaft, so the volume is relatively large. The structures of several synchronous direct drive traction motors currently used generally adopt this kind of structure. structure is designed. Through field experiments and analysis, we found that in the process of assembling the stator and rotor of the permanent magnet motor, with the assistance of precise positioning and guiding tooling, it can ensure that the eccentricity of the stator and rotor can be kept within the theoretical range during the assembling process. Thereby, it is ensured that the pulling force is the main force during the descending process of the rotor. The resistance is smaller than the gravity of the rotor itself. In the vertical state, the combination of the stator and the rotor is completed by the gravity of the rotor itself.