How a BLDC motor spins

The "BL" in the BLDC motor means "brushless", which means that the "brush" in the DC motor (brush motor) is gone. The role of the brushes in a DC motor (a brushed motor) is to energize the coils in the rotor through the commutator. So how does a BLDC motor without brushes energize the coils in the rotor? It turns out that the BLDC motor uses permanent magnets as the rotor, and there is no coil in the rotor. Since there are no coils in the rotor, there is no need for a commutator and brushes for energizing. Instead, the coils act as stators.

BLDC motors use permanent magnets as the rotor. Since there is no need to energize the rotor, no brushes, and commutator are required. The power to the coil is controlled externally.

The magnetic field produced by the fixed permanent magnet in the DC motor (brush motor) does not move, and it rotates by controlling the magnetic field generated by the coil (rotor) inside it. To change the number of rotations by changing the voltage. The rotor of the BLDC motor is a permanent magnet, which rotates the rotor by changing the direction of the magnetic field generated by the surrounding coils and controls the rotation of the rotor by controlling the direction and magnitude of the current to the coils.

Where are BLDC motors with high efficiency, diverse controls, and long life generally used? It is often used in products that can be used continuously due to its high efficiency and long life. For example home appliances. People have been using washing machines and air conditioners for a long time. Recently, BLDC motors have also been used in electric fans, and they have succeeded in significantly reducing power consumption. It is precisely because of the high efficiency that the power consumption is reduced.

BLDC motors are also used in vacuum cleaners. By changing the control system, a significant increase in the number of revolutions has been achieved. This reflects the good controllability of the BLDC motor.

As an important storage medium, the hard disk also uses a BLDC motor for its rotating part. Since it is a motor that needs to run for a long time, durability is important. Of course, it also has the purpose of suppressing power consumption as much as possible. The high efficiency here is also linked to the low consumption of electricity.