Advantages and disadvantages of motors

DC

DC motor is a motor that converts DC electrical energy into mechanical energy. Because of its good speed regulation performance, it is widely used in electric drive. According to the excitation mode, DC motors are divided into three types: permanent magnet, separate excitation and self-excitation. Among them, self-excitation is divided into three types: parallel excitation, series excitation and compound excitation. When the DC power supply supplies power to the armature winding through the brush, the current in the same direction can flow through the N-pole lower conductor on the armature surface. According to the left-hand rule, the conductor will be subjected to a counterclockwise torque; the S-pole lower part of the armature surface The conductor also flows in the same direction, and according to the left-hand rule, the conductor will also be subjected to a counterclockwise moment. In this way, the entire armature winding, that is, the rotor, will rotate counterclockwise, and the input DC electrical energy will be converted into mechanical energy output on the rotor shaft. It consists of a stator and a rotor. Stator: base, main magnetic pole, commutating pole, brush device, etc.; Rotor (armature): armature core, armature winding, commutator, shaft and fan, etc.

The basic structure is divided into two parts: stator and rotor. Note: Don't confuse the commutator pole with the commutator. The stator includes: main magnetic pole, frame, commutator pole, brush device, etc. The rotor includes: armature core, armature (shu) winding, commutator, shaft, fan, etc. Rotor composition The rotor part of the DC motor is composed of armature core, armature, commutator and other devices. The components in the structure are described in detail below. 1. Armature core part: its function is to embed the discharge armature winding and reverse the magnetic flux, in order to reduce the eddy current loss and hysteresis loss in the armature core when the motor is working. 2. Armature part: the function is to generate electromagnetic torque and induced electromotive force, and carry out energy conversion. The armature winding has many coils or glass fiber-coated flat steel copper wire or strength enameled wire. 3. The commutator is also called the commutator. In a DC motor, its function is to convert the current of the DC power supply on the brush into the communication current in the armature winding, so that the tendency of electromagnetic torque is stable. In the generator, it transforms the electromotive force of the armature winding into the DC electromotive force output on the brush end. The commutator is insulated with mica between the cylinders composed of many pieces, and the two ends of each coil of the armature winding are separately connected to two commutating pieces. The function of the commutator in the DC generator is to convert the alternating electric heat in the armature windings into the DC electromotive force between the brushes. There is current passing through the load, and the DC generator outputs electric power to the load. At the same time, the armature coil is also There must be current passing through. It interacts with the magnetic field to generate electromagnetic torque, and its tendency is opposite to that of a generator. The original idea only needs to suppress this magnetic field torque to change the armature. Therefore, when the generator outputs electrical power to the load, it outputs mechanical power from the original idea, completing the function of the DC generator to convert mechanical energy into electrical energy.



What are the advantages and disadvantages of DC motors

DC motor advantages:

1. Good starting and speed regulation performance, wide and smooth speed regulation range, strong overload capacity, and little influence by electromagnetic interference;

2, DC motor has good starting characteristics and speed regulation characteristics;

3, the torque of the DC motor is relatively large

4, maintenance is cheaper;

5. Compared with AC, the direct current of the direct current motor is more energy-saving and environmentally friendly.

Disadvantages of DC motor:

1. DC motors are more expensive to manufacture and have carbon brushes;

2. Compared with asynchronous motors, DC motors have complex structure, inconvenient use and maintenance, and DC power supplies are needed;

3. The complex structure limits the further reduction of the volume and weight of the DC motor, especially the sliding contact between the brush and the commutator causes mechanical wear and sparks, which makes the DC motor have many failures, low reliability, short life and maintenance. The maintenance workload is heavy.

4. Reversing sparks not only cause electrical corrosion of the commutator, but also a source of radio interference, which will have harmful effects on the surrounding electrical equipment. The larger the motor's capacity and the higher the speed, the more serious the problem. Therefore, the brushes and commutators of ordinary DC motors limit the development of DC motors to high speed and large capacity.


Summarize:

Through the above analysis of the advantages and disadvantages of DC motors, we can find that DC motors have good speed regulation performance, relatively cheap maintenance, strong overload capacity, and are less affected by electromagnetic interference, but they are more expensive to manufacture, have carbon brushes, and are reliable. Electrical equipment with low, short life and heavy maintenance workload. Even though DC motors still have many shortcomings, with the help of modern science and technology, DC motors will definitely have a better future.