During the operation of a motor, the most ideal state is to have the stator and rotor iron cores axially aligned, ensuring maximum effective iron length. However, in practical situations, due to the heat generated during motor operation, components will expand and thus require determining the movable end and the fixed end according to the actual structure of the motor, leaving necessary axial clearances. In addition to normal thermal deformation, misalignment of the stator and rotor iron cores can occur during motor operation due to magnetic forces, leading to axial movement of the motor rotor. The direct consequence of this issue is misalignment between the stator and rotor, resulting in axial forces on the bearings.
For Electric motor products, ensuring coaxial alignment of multiple cylindrical surfaces in the radial direction can meet radial mechanical performance requirements. Controlling the magnetic center line prevents axial movement.
In addressing this issue, we introduce the concept of the magnetic center line. The magnetic field of the electric motor is mainly manifested in the air gap between the stator and rotor, known as the "air gap magnetic field." At a certain position, the magnetic field lines of the air gap are all perpendicular to the axis of rotation and have no axial components. This position is referred to as the magnetic center line. Ensuring that the actual magnetic field lines of the product highly coincide with the design requires good equipment and processes to guarantee.