Is the number of poles of the motor rotor fixed?

The number of rotor poles of a motor refers to the number of magnetic poles on the motor rotor; the number of rotor poles of a motor affects the motor speed and torque. For cage-type motors, the number of rotor poles is automatically sensed according to the number of stator poles; theoretically, the same cage-type rotor can cope with motor stators with different pole numbers, that is, the basic performance requirements of the motor can be met through induction matching. However, from the perspective of overall performance compliance, if the slot matching between the stator and the rotor is unreasonable, it may cause problems such as difficulty in starting the motor, starting dead points, and electromagnetic noise. Therefore, in the design of the motor rotor slot shape and number of slots, a relatively optimized slot matching relationship must also be selected.
For wound rotors, the design of the motor windings has fixed the matching relationship with the number of stator poles; for permanent magnet motor rotors, the number of poles is fixed by the arrangement of magnetic steel. Once the number of poles of this type of rotor is fixed, it will not change and can only match the stator with the same number of poles. In motor products, the number of stator poles and the number of rotor poles are important parameters of the motor. The number of stator poles determines the speed of the motor's rotating magnetic field, and the number of rotor poles must be the same as or match the stator. When the two are different or mismatched, the motor stator and rotor magnetic fields are not synchronized, and it is impossible to generate a fixed direction of torque to drive the device to operate.
low voltage electric motor, Ex motor, Motor manufacturers in China, three phase induction motor, Wolong Nanyang Explosion Protection