Working principle of brush motor

The main structure of brushed motor is stator, rotor and brush. The rotating torque is obtained by rotating magnetic field, and the dynamic energy is outputted. Brush and commutator continue to contact friction, in the rotation of the role of conduction and commutation.


The brush motor adopts mechanical commutation, the magnetic pole does not move, and the coil rotates. When the motor works, the coil and the commutator rotate, the magnetic steel and the carbon brush do not turn, and the alternation of the coil current direction is completed with the motor rotating phase changer and brush.


In brush motor, this process is to arrange the two power input ends of each coil into a ring in turn, separated by insulation material, to form something like a cylinder, which is connected to the motor shaft, and the power supply is made of two carbon elements (carbon brush). Under the action of spring pressure, from two specific fixed positions, the power supply of the coil is pressed on the two points of the annular cylinder input from the upper coil power supply.


With the rotation of the motor, the different poles of different coils or the same coil are electrified at different times, so that the N S pole of the coil produces a suitable angle difference between the N S pole of the nearest permanent magnet stator and the N S pole of the nearest permanent magnet stator. The magnetic field is opposite to each other, and the same sex repulsive force is generated to promote the rotation of the motor. The carbon electrode slips on the coil head, like a brush on the surface of an object, so it is called a carbon brush.


Sliding each other, it will rub the carbon brush, resulting in wear and tear, need to replace the carbon brush regularly, the carbon brush and coil junction on and off alternately, and there will be electric sparks, resulting in electromagnetic breakage, interference with electronic equipment.