Introduction to DC motors.

2024-01-11

Direct current motor is a motor that converts direct current energy into mechanical energy. Because of its good speed regulation performance, it has been widely used in electric drive. Dc motor according to the excitation mode is divided into permanent magnet, separate excitation and self-excitation 3 categories, of which self-excitation is divided into parallel excitation, series excitation and compound excitation 3. When the DC power supply is supplied to the armature winding through the brush, the lower conductor of the N pole on the armature surface can flow current in the same direction, and the conductor will be subjected to counterclockwise torque according to the left-hand rule. The conductor under S pole on the armature surface also flows current in the same direction, and the conductor will also be subjected to counterclockwise torque according to the left-hand rule.


In this way, the entire armature winding, the rotor, will rotate counterclockwise, and the input direct current energy will be converted into the mechanical energy output on the rotor shaft. Composed of stator and rotor, stator: base, main magnetic pole, commutator pole, brush device, etc. Rotor (armature) : armature core, armature winding, commutator, rotor and fan, etc.


The basic structure is divided into two parts: the stator and the rotor. Note: Do not confuse the commutator pole with the commutator stator including: main magnetic pole, frame, commutator pole, brush device, etc. Rotors include: armature core, armature (shu) winding, commutator, shaft and fan, etc. The rotor part of a DC motor is composed of an armature core, an armature, a commutator and other devices.


The components of the structure are described in detail below.

1. Armature core part: Its role is to insert the armature winding and the flux at the end, in order to reduce the eddy current loss and hysteresis loss in the armature core when the motor is working.


2. Armature part: The role is to attack electromagnetic torque and induced electromotive force, and carry out energy transformation. The armature winding has many coils or glass-fiber-covered flat steel copper wire or strength enamelled wire.


3. Commutator, also known as commutator, in the DC motor, its role is to convert the current of the DC power supply on the brush into the communication current in the armature winding, so that the electromagnetic torque tendency is stable and unchanged, in the DC generator, it converts the armature winding communication electromotive force into the DC electromotive force on the output of the brush end. The commutator consists of a cylinder composed of many pieces insulated with mica, and each end of the armature winding is separately connected to two commutator pieces.


The role of the commutator in the DC generator is to convert the alternating electric heat in the armature winding into the direct current electromotive force between the brushes, there is current through the load, the DC generator outputs electric power to the load, and there is certainly current through the armature coil. It interacts with the magnetic field to attack the electromagnetic torque, which tends to be the opposite of the generator, the original idea is simply to suppress this magnetic field torque talented dynamic armature change. Therefore, the generator outputs electrical power to the load and outputs mechanical power from the original idea, completing the role of the DC generator in converting mechanical energy into electrical energy.