Skip to content

3 Things You Must Know About Definition, types and Parts Of A Motor

July 27, 2017
3 Things You Must Know About Definition, types and Parts Of A Motor

3 Things You Must Know About Definition, types, and Parts Of A Motor

Later we see most articles talk about electric motor definition but most of them have a small vision about electric motor … I will explain with a brief about the electric motor definition, main parts of a motor (construction of motor) & working principle of the electric motor.

The electric motor is one of the most important inventions of modern times where we rely on it continuously in all things that ranging from movement in the wristwatch to the movement of the spacecraft.

First thing, the main definition of the electric motor is that “ it is a Device that converts electrical energy to movement (mechanical energy) … to go on deep for how this electrical energy converted to mechanical, We will find the answer to this question at the inventor Faraday.

So, let us explain:

How does electrical motor work?


what is the working principle of the electrical motor?


How does an electric motor working physics?

All of these questions were of course in your head and all have the same answer.

The motor idea depends on Faraday’s law … Faraday’s  Law (The induced electromotive force or EMF in any closed circuit is equal to the time rate of change of the magnetic flux through the circuit ).

(motion _ field _ current)

Faraday's law

while we have current and field in the motor, so we can easily take a motion from the motor.

and we can control the movement speed by controlling current and field.

we will Illustrate this In another article.

The second thing is types of electric motor … so we must ask ourselves an important question :

what are the different types of the electrical motor?

Before we talk about the construction of the motor we will talk briefly about the types of the motor due to the different internal structure of each type of motor.
1/ AC motor: Alternating current motor

It may be single phase motor or three-phase motor according to its application … and this motor has some types as:
a- synchronous motor.
b-Induction motor.
c-Special motor.
d-Linear motor.

I will explain every type of AC motor with full details.

2/DC motor: Direct Current motor 

These type of motors fed from DC source … and these motors have some types as:
a- Series motor.
b-Shunt motor.
c- Compound motor.
d-Permanent magnet.
e-Universal motor.
f-Servo motor.
g-Separately excited DC motor.
Each will be explained in subsequent articles.

The third thing you must know about electric motor is :
parts of a motor:

Below you will find all parts of any motor … its general for all types:

Below you will find all parts of any motor … its general for all types:
1/ Enclosure. (AC & DC motors)                                                         
2/Stator.  (AC & DC motors)                                                                 
3/Rotor.  (AC & DC motors)                                                                                                                                   
4/bearings (for ac motors only).                                                              
5/commutator (for dc motors only).                                           
6/Brushes (for dc motors only).                                                       
7/ Conduit box. (AC & DC motors)                                                                                                                                          
8/Eye Bolt.   (AC & DC motors)  

This is the basic structure of all motors but there are minor differences depending on the type of motor. 

 Parts of a motor:

1/ Enclosure: 

The first and main objective of this is to protect the internal parts of the motor therefore, its types vary according to the work environment.
It should be noted that the difference of its type affects the cooling method
Here are some of these types.

Used in         Function       Type            
1/ Indoor application
2/In clean and dry environments
1/Prevent drops of liquid from entering the motor within a 15-degree angle from    vertical                      
        2/ Allows access to air to cool internal files.                               
parts of a motor

Open Drip Proof

1/Chemical environment
2/Not recommended in hazardous environments
Withstand high-pressure wash down totally enclosed wash down

Totally Enclosed wash down            

In hazardous environments Withstand The explosion of gas and steam inside the engine and prevent ignition outside. explosion proof enclosure

Explosion proof enclosures(EXPL)        



2/ Stator:                                

stator of motor

stator of motor

Is the fixed part of the motor and the coils are wrapped around it.

The stator may be windings or permanent magnets slices of the metal sheet called laminations Isolated from each other by varnish to reduce energy loss and heat.

the stator consisted of slices of the metal sheet called laminations Isolated from each other by varnish to reduce energy loss and heat.

It is the moving part of the motor. Fed its coils from AC or DC source for producing field reverses the same for the stator to generates a torque that drives the rotor.
There are different types of it:
a/ squirrel cage.(for AC motor)

squirrel cage rotor of motor

b/Wound rotor.(for AC motor).

wound rotor of motor

c/Armature (In DC motor).

armature rotor of motor

4/ Bearings.(IN AC motor)
Its aim is to reduce friction between the shaft of rotor and Bearings loading. This is for:

a/ reducing corrosion.

b/ Increasing the lifespan of the rotor.
c/Reducing heat resulting from friction.

The development of science and industry has been produced many different types Which are suitable for different types of motors in different operating conditions.
Here are some of them:

bearing of electric motor

5/Commutator.(for DC motor).

commutator dc motor

its important part you can find in DC motors and Its function is to reverse the current in rotor coil So as to continue its rotation in one direction.
It is made of red copper.
6/ Brushes.(for DC motor) 

Brushes DC motor

Provides good communication between commutator and source.

7/Conduit box.

construction of motor

Used to connect power to stator coils.


8/ Eye Bolt. 

eye bolt

To easy carry The motor from it when we want to transport motor from place to another place.
This is the basic structure of all motors, But there are simple differences depending on the type of motor.

you can see a full explanation for this article through this video.




In this article, I focus on three important things that you must know about definition, types, and parts of a motor 

If you like this article please share and react with a comment to give us your feedback.

Thank you for your visiting.
you can see our new topics at

Top Electrical Engineers