Popular knowledge about brushless DC external rotor motor

As the name implies, the design of the external rotor motor is to place the rotor outside and the stator inside the rotor. The external rotor motor makes the magnetic steel originally in the center into pieces and sticks them to the outer shell. When the motor is running, the entire shell rotates, while the coil stator in the middle does not move. The moment of inertia of the rotor of the external rotor brushless DC motor is much larger than that of the internal rotor. The brushless motors of the same series and the same size will show different KV characteristics according to the number of winding turns.

External rotor motor applications

Due to the special design advantages of external rotor motors, they are widely used in home appliances, such as floor fans, fresh air systems, forced exhaust fans, air purifiers, fan lights, humidifiers, and mobile air conditioners.

Note: The motor shaft length and electrical performance can be customized according to customers

Supplementary knowledge about motors

KV value

The rated speed of brushed DC motors is marked according to the rated working voltage. The concept of KV value is introduced for brushless motors, which allows users to intuitively know the specific speed of brushless motors under specific working voltages. Actual speed = KV value * working voltage. This is the actual meaning of KV, which is the speed per minute under 1V working voltage. The speed of brushless DC motors is proportional to the voltage, and the speed of the motor will increase linearly as the voltage increases.

Rated voltage

The rated voltage is the suitable operating voltage for the brushless motor. The suitable operating voltage for the brushless motor is very wide, and the rated voltage is obtained by specifying the load conditions.

Torque (torque)

Torque (moment of force, torque): The driving torque generated by the rotor in the motor that can be used to drive the mechanical load. It can be used to understand the power of the motor.

Speed: The speed of the motor per minute, usually expressed in RPM.

Maximum current: The maximum current that the motor can withstand and work safely

Maximum power: the maximum power that the motor can withstand and work safely. Power = voltage * current

Brushless Motor Power and Efficiency

We can simply understand it as motor output power = speed * torque. Under the same power, torque and speed are in a trade-off relationship. That is, the higher the speed of the same motor, the lower its torque, and vice versa.

About Brushless Motor Magnets

NdFeB magnets are three times more magnetic than the black ferrite magnets that we often see in our daily lives! Of course, the price is more than 10 times that of ferrite magnets. Brushless motors are ultimately permanent magnet motors, and the power and characteristics of permanent magnet motors depend on magnets.