According to the definition of a DC motor, we can define the DC motor as an electrical machine that is used for converting electrical energy into mechanical energy. The input electrical energy in the form of direct current which is then converted into mechanical energy.
Therefore, we can say that if an electrical motor is operated in the direct current it can be called a DC motor.
Parts of DC Motor
The main parts of a DC motor are shaft, armature conductors, pole shoe, frame, inter-pole, field winding, and commutator.
In a DC motor, the armature is a cylinder of magnetic laminations. These laminations are insulated from each other. The armature and the axis of the cylinder are perpendicular to each other. The armature is the rotating part which is separated from the field coil by an air gap. The armature is also known as the rotor.
The non-moving part of the DC motor is known as the field coil. The field coil has the winding wound to it so has to produce a magnetic field. This forms an electromagnet which has a cylindrical cavity between its poles.
Commutator and Brushes
The cylindrical structure made using copper segments in the DC motor is known as the commutator. These segments are stacked together and are insulated from each other using mica. The main function of the commutator is to provide electrical current to the armature winding.
The brushes are made using graphite and carbon. The function of brushes is to conduct electric current from the external circuit to the rotating commutator. Therefore, we can say that the commutator and the brushes are units that are used for transmitting the power from the static electrical circuit to the mechanically rotating rotor.
Types of DC Motor
Self-excited DC motor and separately excited DC motor are the two types of DC motors.
Self-excited DC motor can be further classified as shunt wound DC motor, series wound DC motor, and compound wound DC motor.
Applications of DC Motors
The application of DC motors varies depending on the type of DC motor. The following are the applications of shunt DC motors:
- Machine tools
- Lathe machines
- Blowers and fans
- Milling machines
The following are the series DC motor applications:
- Electric locomotives
The following are the applications of cumulative compound DC motor which is a type of compound DC motor. (A compound DC motor has both shunt and series field winding):
- Rolling mills
- Heavy planers
Stay tuned with BYJU’S to learn more about the working principle of the DC motor.