What are the different functions of DC motor windings?

A motor that converts direct current energy and mechanical energy into each other. When it is used as a motor, it is a DC motor, which converts electrical energy into mechanical energy; When the generator is running, it is a direct current generator, which converts mechanical energy into electrical energy. The DC motor is composed of two parts, a stator and a rotor, and there is a certain air gap between them.

The main feature of its construction is the presence of an armature with a commutator. The stator of the DC motor is composed of components such as the base, the main magnetic pole, the commutation magnetic pole, the front and rear end covers, and the brush holder. The main magnetic pole is the main component that generates the air-gap magnetic field of the DC motor, which is composed of a permanent magnet or a laminated core with DC excitation windings.

The rotor of a DC motor is composed of an armature, a commutator (also known as a commutator) and a rotating shaft. The armature is composed of two parts: the armature core and the armature winding. The armature core is made of stacked sheets of silicon steel, and the cogging is evenly distributed in its outer circle, in which the armature windings are recessed.

A commutator is a mechanical rectifier component. After the commutation pieces are stacked into a cylindrical shape, they are molded into a whole with metal clips or plastic. Each commutator piece is insulated from each other.

The quality of the commutator has a great influence on operational reliability. When the prime mover drives the armature winding to rotate between the main magnetic poles N and S, the armature winding induces an electromotive force, which is rectified to DC by the brush and commutator device, and then leads to the external load (or power grid) to supply power to the outside world, and the motor runs as a DC generator. If an external DC power supply is used, the DC current is directed to the armature winding through the brush commutator device, and the current interacts with the magnetic field generated by the main magnetic pole to generate torque, which drives the rotor to work with the mechanical load connected to it, and the motor runs as a DC motor.

There is a brushed disc winding motor. The brushed disc winding motor is bonded to a cylinder block with rare earth materials, and the disc winding formed by enameled copper wire is placed in the cylinder block to form a rotor. The phase of the motor is adjusted by a mechanical commutator.

The mechanical commutator adjusts the voltage phase by the friction between a fixed carbon brush and a rotating copper commutation surface. The brushes of this kind of motor have been worn out in use, and the life of the motor is difficult to exceed 2000h. At the same time, due to the high speed of the motor, two-stage gear reduction must be adopted, which brings two problems, one is the noise, the other is the efficiency loss, the rated efficiency of the motor after deceleration can often only reach 68% 72%.

The capacity of the battery used in the electric bicycle is limited, generally the capacity of 36V 12Ah, if the motor efficiency is not high, the power consumption will increase, affecting the driving range.

A pair of stationary main poles N and S of DC excitation are installed on the fixed part (stator) of the two-pole brushed DC motor, and an armature core is installed on the rotating part (rotor). There is an air gap between the stator and the rotor. On the armature core, an armature coil composed of two conductors, A and X, is placed, and the first and last ends of the coil are connected to two arc-shaped copper plates, which are called commutation plates.

The commutators are insulated from each other, and the whole composed of commutators is called a commutator. The commutator is fixed on the rotating shaft, and the commutator and the rotating shaft are also insulated from each other. A pair of fixed brushes B1 and B2 are placed on the commutator piece, and when the armature rotates, the armature coil is connected with the external circuit through the commutator piece and the brush.

Alternating current.

For DC motors, DC power is added to both ends of the armature, which becomes AC power through the commutator and flows through the armature windings. For DC generators, it is an inverse process.

When the coil edges are under the magnetic poles of different polarities, how to change the direction of the current flowing through the coil in time, that is, the so-called commutation. For this purpose, it is necessary to add a device called commutator, which can be combined with brushes to ensure that the current in the side of each lower coil is always in one direction, so that the motor can rotate continuously, which is the working principle of DC motor.

The excitation winding of the DC motor is fixed, the carbon brush is fixed, and the commutator accepts DC to the armature, due to the rotation of the armature, the direction of the current in the armature coil is constantly alternating, and the current in the armature can be said to be alternating current.

Because the stator of a DC motor has a fixed magnetic field, and if the armature winding is also DC, the magnetic field does not change, and the rotor cannot rotate, so the armature must be AC (but not a sine wave).

As long as it is direct current, it will always be direct current no matter where it flows, unless it flows into the oscillator, it becomes AC.

It seems that you are very entangled in this problem, so please carefully study the principle of the DC motor and the role of the commutator, and be sure to understand it, so that you are not only a junior electrician, but also a senior electrician until a senior technician!

What is the role of the commutator:1Sliding contact power supply to the armature. 2.When the armature turns to a certain angle, change the direction of the current entering the armature winding or switch the turned on winding to achieve the purpose of continuous rotation.

Think about it: what would happen if you were connected directly to DC instead of a commutator? The armature will become a magnet, directly or after turning at a certain angle, it will be firmly attracted by the stator magnetic field, let alone rotate, and you can't twist it.

The windings of DC motors are commonly used in two forms: series winding and parallel winding.

Series winding: Series winding refers to connecting armature windings and electric field windings in series. In series windings, the armature windings and the electric field windings are supplied with power from the same current source.

This form of winding allows the armature winding and the electric field winding to share the same current, so that the armature and electric field produce the same magnetic field direction. The series winding is characterized by a torque proportional to the current, which is suitable for applications that require high torque, such as starting heavy loads and starting large loads.

Parallel winding: Parallel winding refers to the armature winding and the electric field winding connected in parallel with the current source respectively. In parallel windings, the armature windings and the electric field windings are each supplied with power from separate current sources.

This form of winding causes the armature and the electric field to produce opposite magnetic field directions. The shunt windings feature a rotational speed proportional to the voltage, making them suitable for applications that require high-speed operation, such as power tools and fans.

The choice between series or parallel windings depends on the specific application requirements. Factors to consider include the required torque and speed range, as well as current or voltage requirements. Depending on the requirements of the application, the appropriate winding form can be selected to meet the performance requirements.

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There are two commonly used forms of DC motor winding: stacked winding and wave winding.

The windings of the motor are mainly divided into permanent magnet windings and excitation windings of DC motors and stator windings and rotor windings of AC motors.

Among them, the stator winding of the AC motor can be divided into the main winding and auxiliary winding of the single-phase motor, and the stator winding of the three-phase motor has different connection methods such as star and triangle.

In a DC motor, the armature winding is made up of a number of coils, which are usually equipotential, which are connected in series to form a complete armature winding.

Specifically, each coil of the armature winding is made up of a number of winding coils, which are usually made of copper or aluminum wire. These winding coils are connected together in a certain order to form a complete coil.

In armature windings, one terminal of the first coil is usually connected to the positive terminal of the motor, while the other terminal of the last coil is usually connected to the negative terminal of the motor. In this way, when an armature winding is passed with an electric current, the current will flow through all the coils as they are all connected in series in one collapse. This series connection helps to increase the resistance of the armature windings, thereby reducing the current and power losses of the motor.