If you want to learn how components, such as motor brushes, the commutator, the permanent magnets, and the electromagnetic coil all work together to generate the movement of a permanent magnet DC motor, our expert Hunter Stephenson explains the essentials in this video.
What is a DC motor?
A DC motor is a rotary machine that converts electric energy into mechanical energy.
Inside the stator, or the motor housing, the permanent magnets are mounted. These magnets create a constant magnetic field.
The armature consists of an electromagnetic coil connected to a DC power source, and running all through the motor is the shaft. The components all rotate inside the motor.The two brushes touch the commutator that leads the DC power from the source to the electromagnetic coil.
Ball bearings ensure minimal friction between the shaft and the outer elements of the motor.
How does a DC motor work?
The functionality of a DC motor is based on the principle of induction. Induction is the current that is generated inside the magnetic field, when the inductor or magnetic field rotates.
When current flows through the armature coil, an electromagnetic force is induced, and the coil begins to rotate.
When the coil reaches the opposite magnetic field, the commutator rings will touch the power source of the opposite polarity. This means that the electromagnetic pull will change direction, and the coil will continue to rotate in the same direction.
What is DC motor efficiency?
The efficiency of a DC motor is the ratio between the input power and the output power measured in Watt. And the power input is proportional to the load that must be moved. Many of the motor parts have a negative impact on the motor’s efficiency resulting in heat being generated. This is also true for very high or low ambient temperatures that are often present in the working environments of industrial actuators.
What can you do to achieve optimal actuator performance?
To achieve optimal actuator performance, you need a stable power supply, the right cabling and the right input voltage:
A stable power supply: Should match the nominal voltage of the motor.
Cabling: The shorter and thicker the cables, the less resistance there is for the input current to reach the DC motor.
Input voltage: In case you choose to run a DC motor with over or undervoltage, it can overload the motor.
A Direct Current (DC) motor is a rotary machine that converts electrical energy into mechanical energy. This functionality is based on the principle of induction – an electromagnetic force created by input current, which in turn creates a rotational movement.
