Today, the machines and tools around us often utilize brushed and brushless DC motors to provide rotational motion, both of which essentially perform the same function, converting electrical current into rotational motion.
Brushed motors have been around for over 100 years, while brushless motors have been around since the 1960s. Both motors may look similar, but their design and operation are completely different. It is important to choose the right motor and ensure it is configured correctly for your application to get the best results.
In this article, AIP will cover the differences between brushed and brushless motors to better understand which motor is best suited for their application.
Ⅰ. Brushed DC motor
A brushed DC motor is mainly composed of components such as an armature, a commutator, and a magnetic field. These components, together with the DC power supply, form a rotating motor. As shown below.
(Brushed DC motor structure)
The picture above is a simplified armature. The armature of a brushed DC motor has multiple coil windings. The brushes charge the commutator, which carries current through the armature in opposite polarity to the permanent magnet, which causes the armature to rotate due to the attraction of the magnet.
Brushed DC motors are easy to operate as they are one of the simplest motor types, but they have a shorter lifespan compared to brushless motors. Sparks are a common problem with brushed motors because the brushes are in physical contact with the commutator. Over time, this physical contact also wears the brushes and causes some energy loss due to the friction created.
Ⅱ.Brushless DC motor
Brushless DC motors (BLDC) eliminate the inefficiency issues of brushed motors. The motor consists of permanent magnets and coils that cause the central permanent magnet to rotate around the coils through a series of perfectly timed energization intervals. As shown below:
(Brushless DC motor structure)
The difference between brushed motors and brushless motors is that brushed motors are mechanically driven while brushless motors are electronically driven.
①Brush motor: The stator (fixed part) contains permanent magnets, while the rotor (moving part) contains electromagnets. The carbon brushes are in physical contact with the commutator in the rotor, transmitting voltage to it. This voltage creates an electromagnetic field in the rotor. Rotational motion can be achieved by continuously flipping the polarity of the magnetic force through the commutator. Although this design is simple, it also has its disadvantages:
■ Lower efficiency
■ Shorter life
■ Requires more maintenance
②In brushless motors, the situation is the opposite. The rotor contains permanent magnets and the stator generates an electromagnetic field. An electronic controller replaces the brushes and generates a three-phase variable current to continuously power the motor coils. This creates a rotating magnetic field in the stator that powers the rotor magnets and creates rotational motion. Brushless designs have some disadvantages:
■ Requires electronic controller
■ More expensive
■ The structure is more complex
③Which one is better, brush or brushless?
Both designs have their merits, but neither is better. At the end of the day, cost is probably the biggest factor.
Brushed motors can be mass-produced and cost less. In addition to price, the advantages of brushed motors include:
■ Easy to operate
■ Available in a variety of sizes and grades
■ Easy control
■ Suitable for lower duty cycle
If your application requires a higher level of control and practicality outweighs the cost, a brushless motor may be a better choice. The advantages of brushless are:
■ Precise speed control
■ More suitable for continuous or long-running work cycles
■ Longer life
■ Reduce maintenance
■ High efficiency
While it is possible to use a controller on a brushed motor, the cost may make brushless motors a better choice.
Ⅳ.AIP brushed and brushless motor tester
AIP focuses on global motor testing. The above is what AIP has shared with you about the difference between brushless motors and brushed motors. For testing brushless motors and brushed motors, AIP already has relatively complete and mature testing solutions. Here are some of our brushed motor testers and brushless motor testers.
(Brushed motor testers) (Brushless motor testers)
AIP knows motors, If you have any questions or would like to discuss motors and our motor tester, please feel free to contact us! Tel/Whatsapp: +86-13969776659 or E-mail: email@example.com, We are experts in this field and want to help you find the best motor testing solution for your application.