The difference between the motor and brushless motors

As already mentioned in the basic working principle of dc motor, dc motor is the use of carbon brush commutation. Because carbon brush friction, making the motor brush and shorten service life. At the same time, the brush in the process of high-speed operation which sparks, also on the surrounding electronic circuit to form interference. For this reason, people invented a without carbon brush dc motors, also known as brushless motor (usually 无刷电机) 。
brushless motor winding as the stator, and permanent magnet as rotor ( As shown in figure 1) The structure with a brush motor, to the contrary. Brushless motor using electronic circuit switching winding current order to produce a rotating magnetic field, promote the rotation of the rotor. Figure 1

the principle diagram of the brushless dc motor
brushless motor with no carbon brush, no maintenance long life, high precision of speed regulation. Therefore, brushless motor is rapidly replacing the traditional brush motor, household appliances with frequency conversion technology ( Such as frequency conversion air conditioning, frequency conversion refrigerator, etc. ) Is the use of brushless motor, the cooling fan of almost all use brushless motor.