Lately, brushless DC motors have increasingly become of common use in many applications. This is due to the presence of some useful advantages that they entail compared to other motor types and that relate to their nature and composition. In the following lines we are going to explain how brushless DC motors (BLDC) are structured and, after that, we are going to list the elements that make them so important nowadays.
Differently from brushed DC motors, their brushless version do not use brushes, as the name suggests. Therefore, the following question naturally arises: “how can brushless DC motors pass current to the rotor coil?”. They simply do not, since coils are not located in the rotor. On the contrary, the rotor is a magnet which is fixed in place on the stator. Therefore, since the coils are stationary, brushes are not requested. While a brushed motor generates energy by controlling the magnetic fields created by the coils on the rotor, a
BLDC motor generates itby changing the direction of the magnetic fields that are activated by the fixed coils and that causethe stationary magnet to rotate. In order to control the rotation process it, is necessary to adjust two elements of the electricity into the coils: magnitude and direction.
To begin with, brushless DC motors are more efficient than most of other motor types. In fact, they are able to control constantly at maximum rotational force, called torque, and can achieve high amount of power. In addition, due to the absent of a brush, BLDC motors function considerably more quietly and have high durability compared to the ones equipped with the brush, which often wear down as a result of continuous moving contact and the sparks produced during the process. Finally, and perhaps most importantly, they are extremely easy to control. By using feedback mechanisms, they can reach the precise and aimed torque and rotation speed, an element that results in a consistent reduction of energy consumption and heat generation.
BLDC motors are being used widely nowadays. Due to a continuous decrease in costs since their birth they have become a perfect fit for consumer electronics such as washing machines and heating and ventilation devices such as air conditioners. However, they have become crucial for expanding sector as well, such as model engineering and industrial engineering,but also for transports of any kind. For instance, they are the kind of motors adopted by Formula E, because they guarantee considerable power associated with a long lasting life. Moreover, new developments and improvements are constantly made with the aim to achieve results that are even difficult to imagine.