Basic Functions Of A Brushless DC Motor

A lot of goods that we use in our day to day lives use a brushless DC motor often referred to as BLDC motor. Things like floppy drives, computer printers, electric wheelchairs, refrigeration units, and golf trolleys use this device. The main reason for people to opt for this motor is its efficiency. It has few moving parts and hence this reduces friction and wear and tear making the life span of the motor longer. Also, due to its limited number of moving parts, the probability of the motor being dysfunctional is also less. Even though the BLDC motor is more expensive than its peers, it seems to attract a user base that keeps an eye out for the future, as this motor has a long life.

The motor has a unique design. There is a magnet in the centre, and it is surrounded by three (at times more) electro magnets from its outer side. This combination is held together in place with the help of a ring. When the electro magnets are switched on, they create a pull towards its opposite pole, and a repelling force to its similar pole. This electro magnetic play turns the magnet (often called commutator) in the centre and enables it to spin. Since it is connected to the gearbox, the power flows into the device that is being operated with the help of the brushless DC motor.

Though this is the basic functioning of a brushless DC motor, it can be constructed with a few variations. The commonly used configuration is by using the permanent magnets as part of the rotor. However, there is another configuration, called the external rotor configuration. In this mode, the coils form the core, and the permanent magnets spin inside a hanging rotor that surrounds the core. Even the electrical winding configurations can be altered. Some use the Delta configuration while some use the Wyne structure. The former type connects three windings to look like a triangle, while the latter forms a star-like structure.

Any form of brushless DC motor is a wise choice given the efficiency and cost effectiveness it provides. It is due to this property that a brushless DC motor finds itself being used in RC cars, engineering parts, and motion control systems.