What is a Brushless DC Motor?
A brushless DC motor (Brushless DC motor) is a motor that uses a brushless converter to achieve synchronous rotation between the rotor magnetic field and the stator magnetic field.
BLDC motor consists of three parts: stator, rotor and electronic controller. Several coils with the same number of phases are wound on the stator, and the electronic controller outputs timing signals to the coils on the stator, so that the magnetic field between the coils changes continuously with time, thereby driving the rotor to rotate.
Structure of Brushless DC Motor
There are some differences in the structural design of brushless DC motors from traditional brushed DC motors. The structure of BLDC motor generally includes three parts: rotor, stator and electronic controller.
Rotor: The rotors of BLDC motors generally use permanent magnet materials, such as NdFeB, SmCo, etc. The number of poles of the permanent magnets on the rotor is usually equal to the number of coils of the stator to achieve synchronous rotation. In rotor design, the shape and field distribution of the permanent magnets also need to be considered to meet the specific needs of the motor.
Stator: The stator of a BLDC motor usually employs multi-phase windings to achieve high efficiency and high power density of the motor. In the stator design, factors such as the number, shape, size and layout of the coils need to be considered to achieve the best electromagnetic performance.
Electronic controller : The electronic controller of the BLDC motor usually uses a special chip or module to realize the control of the rotor. In controller design, factors such as control algorithm, power supply circuit, and drive circuit need to be considered to achieve efficient control and drive.
Diffenrences Between Brush DC Motor
Compared with brushed DC motors, the structural design of BLDC motors has the following differences:
Brushless converter: The rotor of the BLDC motor does not need carbon brushes and commutators to change the direction of rotation, but uses an electronic controller to control the timing signal to realize the alternate work of the coils on the stator, thereby realizing the synchronous rotation of the rotor .
Permanent magnet rotor: The rotor of a BLDC motor generally uses permanent magnet materials to improve the power density and efficiency of the motor.
Multi-phase windings: The stator of a BLDC motor usually employs multi-phase windings to improve the efficiency and power density of the motor.
What are the advantages of Brushless DC motors ?
The main advantages of BLDC motors over traditional brushed DC motors are:
BLDC motors do not need to use brushes and commutators, reducing mechanical friction and energy loss, so higher efficiency can be achieved.
| Parameter | BLDC Motor | DC Brush Motor | Advantages of BLDC Motor |
|---|---|---|---|
| Efficiency | High (85-90% or more) | Moderate (75-80%) | BLDC motors are more energy-efficient |
| Lifespan | Long | Shorter | BLDC motors have a significantly longer lifespan. |
| Speed Range | Wide | Limited | BLDC motors can operate at higher speeds with better control. |
| Torque | +++++ | +++ | BLDC motors provide better torque |
| Heat Dissipation | Better | Poorer | BLDC motors dissipate heat more effectively |
| Noise Level | Low | Higher | BLDC motors operate more quietly |
| Control Precision | High (Electronic commutation) | Lower (Mechanical commutation) | BLDC motors offer precise speed and position control |
| Size and Weight | Compact and lightweight | Heavier |
Attention: The above comparison is based only on DONCEN MOTOR’s product series. Different product designs have different standards. Please consult our engineering team for specific motor parameter questions.
Types of BLDC Motors
According to different structural designs, brushless motors are divided into inner BLDC motors and outrunner BLDC motors.
Related Article: Outrunner BLDC Motor vs Inner BLDC Motor
Applications for BLDC Motors
Thanks to their superior design, BLDC motors are favored by engineers for high-value applications that demand precise control and extended operational life.
