What is the function of the commutator in DC motors?

In a DC motor, the commutator plays a crucial role in ensuring that the armature receives the correct current direction needed for continuous rotation. Specifically, the primary function of the commutator is to change the direction of the current in the armature windings as the motor turns. This reversing of current direction aligns with the magnetic field provided by the stator, allowing consistent torque in one rotational direction.

When the armature spins, the segments of the commutator switch the electrical connections between the rotating armature windings and the external circuit. This switching ensures that as the armature rotates and the magnetic fields interact, the armature continues to rotate in a single direction rather than oscillating back and forth. Thus, the commutator effectively changes the direction of the current supplied to the armature, which is essential for the functioning of DC motors.

While supplying power to the armature and regulating speed are important functions of the overall motor system, these roles are not directly attributed to the commutator itself. Additionally, the commutator does not act as a heat sink; rather, it is primarily involved in the electrical switching required for the motor's operation.