Advantages of DC Brushless Motor over Brushed Motor

DC brushless motors are also known as electronically commutated motors and they are powered by a DC power supply through an integrated inverter or switching power supply. The inverter generates an AC signal which powers the motor.

In a DC brushless motor which can be found at Teco Electric Co. Ltd., the rotor is normally a permanent magnet synchronous motor, an induction motor or a switched reluctance motor. The permanent magnets in the motor rotate around an armature that is fixed which is better than a moving armature that tend to have connecting current problems. Instead of the brush, there is an electronic controller whose job is to switch the phase to the windings. This keeps the motor turning. Without the brush/commutator, a solid-state circuit is used for timed power distribution.

An electronic controller replaces the brush/commutator assembly of the brushed DC motor, which switches the phase continuously to the windings to keep the motor turning. The controller distributes the power in specified timings by using a solid-state circuit rather than the brush/commutator system.

There are quite a few advantages that the DC brushless motor has over the DC brushed motor. These include increased reliability, increased efficiency, less noise, longer life and removal of ionising sparks from the brush. There is also a reduction in the electromagnetic interference. The internal part of the motor can be protected from dirt and grease because of their closed model. This is possible because airflow is not needed for cooling inside the motor as the housing supports the windings. This means that the windings can be cooled by conduction.

Implementation of DC brushless motor commutation in software is possible with the use of a microprocessor computer or a microcontroller. Electronic commutation lends to speed limiting, holding torque, stepped operation and better flexibility which are not possible with brushed motors.