Stator

The term stator comes from the combination of two words. The first is stationary, and the second is a rotor. In short, a stator is a fixed part where a rotor is turned. The stator is one of the most important parts of an electric motor which, unlike the rotor, is always static. This characteristic fits in with the general function of an electric motor, which is to convert electrical energy into energy of motion – generally known as kinetic energy. The stator is the part in charge of working with this electrical energy to create a magnetic field.

The stator, therefore, is the part that acts as the magnetic pole within the electric motor; the movement of a compass could therefore be compared to a rotor’s movement, and the movement of magnetic north to a stator’s movement. The role of the rotor is to move in order to adjust itself to a fixed point at all times, which is the stator.

Functions of a stator

A stator acts as a reference point in an electric motor. As mentioned above, it is a part which, thanks to the position it occupies, allows the rotation of the rotor to take place. Generally, the stator consists of laminated steel sheet that allow the magnetic flux to pass through. In asynchronous motors there is alternating current which rotates at a speed different from that of the magnetic field of a stator. It can therefore be said that one of the functions of the stator is in fact to create a magnetic field by acting within the whole electric motor circuit like an inductor element. Its name does actually come from the fact that it remains static and produces an electromagnetic field that serves as a reference for the moving part, which is the rotor.

It should be noted that there are different types of rotors using different technologies to generate magnetism with respect to the stator. They may in particular be externally powered rotors, magnet rotors, induction rotors, etc. However, regardless of the type concerned, they always operate in the same way: one part made up of independent coils responsible for generating a rotating magnetic field.

At the same time, the size of the stator should also be noted as another important factor: the size of the stator will depend to a large extent on the technology with which the motor operates. For example, in the case of permanent magnet rotors, the stator takes up little space. However, in the case of induction motors, there is a larger stator which is actually the part that contains the rotor.

In conclusion, it can be said that the functions of the rotor and the stator are as important as the battery and controllers themselves, as they are the essential part of the motor’s movement and energy transformation.

What are the differences between the rotor and the stator?

When talking about rotors and stators, it is possible to list some of the most important differences between them. First of all, it can be said that the rotor is the moving part of an electric motor, while the stator is the fixed part. In the case of the stator winding, this has a three-phase power supply that stimulates the rotor and sets it in motion. Another of the most notable differences lies in the parts that go to form it: the stator core, its outer frame and its winding. In the case of the rotor, it consists of the core and the field winding, which are parts of the motor.

Another difference with respect to the stator winding is that, as it is subjected to a high voltage, it remains insulated. This is not the case with the rotor winding, which has a lower degree of insulation. As regards their layout, the stator’s can certainly be described as more complex than the rotor layout. There is also a difference in the cooling system. Stator cooling is better than in the case of the rotor precisely because it is in a fixed position. The last point is the pressure drop of the rotor, which is lower than that of the stator. This is mainly due to their weight difference.

Major factors in relation to the stator and rotor

The stator and rotor are two essential parts of an electric motor. In fact, if one of the two is missing, it is impossible to generate movement with it. The stator is responsible for generating a magnetic field that interacts with the rotor. As previously mentioned, the rotor serves to convert electrical energy into mechanical energy.

This is precisely why the design and quality of both items is so important. Quality and good design will have a direct impact on the potential efficiency of the motor. They are also extremely important factors in relation to the performance of the motor. Indeed, if the rotor and stator are well laid-out and designed, it is possible to improve the energy efficiency of the motor. Not only is it able to produce energy more efficiently, but it will also be able to reduce its energy consumption.

Another essential point related to the quality of the stator and the rotor, in addition to their design, is their service life. If these requirements are met, this will have a positive influence on their service life. With the right design and quality, it is possible to increase the lifetime of the motor. Thus, it can be said that both the rotor and the stator are two essential parts in the operation of an electric motor, as well as in its performance and lifetime.

Stator types

There may be different types of stators, depending on the type of machine or motor in question. In the case of AC machines, the stator is normally in the form of a cylindrical tube with a wall thickness of a certain size. In the case of the slots where the coils are fixed, they are formed with crown wheels made of magnetic sheets and with teeth on the inner part of the circle.

In the case of a DC machine, on the other hand, the stator generally consists of a cylindrical steel armature. The pole pieces (also called poles) are attached to the inside, together with the required coils.

There are therefore two types of interaction. In the case of alternating current, this is an interaction with the rotating field to produce the torque. Its structure is hollow and consists of a stack of laminated magnetic steel. The direct current is an interaction with the moving part that generates torque with respect to the machine shaft.