How does a motor rotate?
1) Motor rotation relies on magnets and magnetic force
Around a permanent magnet with a rotating shaft, ① the magnet rotates (to generate a rotating magnetic field), ② then according to the principle that N poles and S poles attract each other and same poles repel each other, ③ the magnet with the rotating shaft will rotate.
This is the basic principle of motor rotation.
When current flows through a wire, a rotating magnetic field (magnetic force) is generated around it, causing the magnet to rotate. This is actually the same operating state.
In addition, when the wire is wound into a coil, the magnetic force is synthesized to form a large magnetic field flux (magnetic flux), generating N poles and S poles.
In addition, when an iron core is inserted into the coiled wire, the magnetic lines of force become easier to pass through, and a stronger magnetic force can be generated.
2) Actual rotating motor
Here, as an actual method of rotating motors, a method of creating a rotating magnetic field using three-phase AC and coils is introduced.
(Three-phase AC is an AC signal with a phase interval of 120°)
The synthetic magnetic field in the above ① state corresponds to the following figure ①.
The synthetic magnetic field in the above ② state corresponds to the following figure ②.
The synthetic magnetic field in the above ③ state corresponds to the following figure ③.
As mentioned above, the coils wound around the core are divided into three phases, and the U-phase coil, V-phase coil, and W-phase coil are arranged at intervals of 120 degrees. The coil with a high voltage produces an N pole, and the coil with a low voltage produces an S pole.
Each phase changes according to a sine wave, so the polarity (N pole, S pole) and its magnetic field (magnetic force) generated by each coil will change.
At this time, looking at the coil that produces the N pole alone, it changes in the order of U-phase coil → V-phase coil → W-phase coil → U-phase coil, thereby rotating.
