motor_what2
Magnetic Force
<How Does a Motor Work?>
Motor Rotation Using a Magnet/Magnetic Force
The basic operating principle of a motor is as follows.
Around a permanent magnet having a rotational axis:
① When the outer magnets rotate (referred to as a rotating magnetic field),② The N and S poles attract and repel each other, ③ Causing the magnet with the rotational axis (center) to turn.
![Basic Operating Principle of a Motor](/documents/11303/4385951/motor_what_en+%282%29.gif/7418a663-022b-4a93-9dc1-93c8a5ae4c8a?t=1543808358187)
Alternatively, supplying current to a conductor generates a magnetic field around, creating a magnetic force (Rotational magnetic field). This results in the same effect as rotating a magnet.
![Here magnetic field is generated by passing a current through a conductive wire](/documents/11303/4385951/motor_what_en+%283%29.gif/083c0c88-cf6a-4b96-86b0-08a771f950c1?t=1543808357480)
If we wind a conductive wire into a coil the magnetic force is combined, generating a large magnetic flux along with North and South poles.
![The magnetic force can be further strengthened by utilizing an iron core to increase magnetic flux density](/documents/11303/4385951/motor_what_en+%284%29.gif/09197e6e-f07d-42b0-a3dd-fa7e92dd9ab5?t=1543808356760)
Actual Motor Operation
Here we see an actual method used for rotating a motor by generating a rotational magnetic field from a 3-phase AC source and conductive coils (3-phase AC is an AC signal with phases shifted 120°).
![Current Change (Change in Magnetic Field Strength)](/documents/11303/4385951/motor_what_en+%285%29.gif/c24eb9c9-ac4f-4004-9037-496357eb163b?t=1474336108227)
- The synthetic magnetic field in ① above is shown in ① below
- The synthetic magnetic field in ② above is shown in ② below
- The synthetic magnetic field in ③ above is shown in ③ below
![Results from the above diagram](/documents/11303/4385951/motor_what_en+%286%29.gif/d5c9f2a3-c074-4a50-bf43-c1a3b15a7bda?t=1474336103890)
As mentioned above, the 3 phase coils (U, V, and W) are wrapped around an iron core, positioned 120° apart, with the higher voltage generated at the North pole(N) and the lower voltage at the South pole(S). Since each phase varies sinusoidally, the pole (N/S) generated from each coil will continue to change, along with the magnetic field.
If we look at just the North pole phase, it switches in order from the U coil → V coil → W coil → U coil, enabling rotation.