Why are brushed motors so widely used?

Most of our common electric products use brushed DC motors such as: smart home appliances, electric toys, sweeping robots, office equipment, bank communication equipment, electronic locks, beauty instruments, electric toothbrushes, power tools, industry, medical equipment, etc. Wait, why are miniature brushed DC motors so widely used?

The brushed DC motor is composed of stator (casing, bearing, magnetic field), rotor (iron core assembly, commutator/commutator, varistor, copper wire/enameled wire, tin wire), end cover (cover plate components) , bearing, collar, gasket, brush holder) three parts, the stator is installed with fixed magnetic poles, the rotor is installed with windings and commutator, when a bit tired, the direct current will enter the winding through the brush and the commutator, resulting in The armature current, the interaction of the armature current magnetic field with the main magnetic field will generate electromagnetic torque, which will make the motor rotate. When the motor is running, the brushes and the commutator will constantly rub. The function of the commutator in the micro motor is to convert the input DC current into the armature winding through the brush (or carbon brush) and the commutator into an alternating current.

The reason why the brushed DC motor is widely used is its low manufacturing cost, simple and convenient speed regulation, and under the premise of meeting the necessary performance, low cost and sufficient reliability, the brushed motor is a good choice. The speed adjustment can be realized by directly adjusting the input voltage, which greatly reduces the cost, and the starting torque is large. It can be matched with different types of gearboxes to increase the torque and reduce the speed.

Micro brush DC motor selection principle: the brush has a short life and low noise; the carbon brush has a long life, but the noise will be relatively high, and the faster the speed, the greater the noise; the more gear sets of the reduction motor, the reduction ratio will be The larger the gear, the lower the speed, the greater the torque, and the lower the efficiency; the fewer gear sets, the lower the torque, the higher the speed, and the higher the efficiency.