Question

Explain the function of: armature,brushes and split rings in an electric motor.

Answer 1

Hint: In order to solve this question we need to understand first what an electric motor is and the principle behind it. Electric motor is a device which converts electrical energy into mechanical energy. The principle behind it is Faraday’s law of Electromagnetic induction according to which electromagnetic induction is induction of electric current in a loop if there is change in flux per unit time. Now the flux could be changed by three methods. First by changing magnetic field amount we can induce emf across the loop and hence current induces, second is by changing the area of the loop under magnetic field and third is by changing orientation of loop in magnetic field.

Complete answer:
So in an electric motor we use several devices that induces electric current in it and due to electric current torque produced which rotates the electric motor either clockwise or anti clockwise so that electric energy is converted to mechanical energy.

Function of armature: Armature is a component which carries AC current. It can be used both on rotor or stationary parts of electric motors. Armature function is to produce torque. Actually due to relative motion of armature windings and magnetic field an electromotive force or EMF induced which opposes the armature current, and the armature converts electric power to magnetic power in the form of torque.

Function of brushes: Brushes are the mediator which act as contact between stationary wires and moving parts. It helps in conduction of current with the help of a commutator.

Function of Split rings: Split rings or commutator is used to change the direction of current so as to continue rotatory motion. If the current does not change after each half rotation of the motor then the motor would eventually stop the motion because the change in flux is zero as current becomes stationary.

Note:It should be remembered that Electric motors are two types DC electric motor and AC electric motor. Difference in two is that the armature winding carries DC current in the DC motor whereas it’s winding carries AC current in the AC electric motor. So the DC motor is fast but not synchronized. Also nowadays brushless DC motors are being produced.