How to tell if a DC motor is brushed or brushless?

A few key differences between DC brushed and brushless motors can help you identify which type of motor you’re dealing with. Brushed DC motor typically has physical brushes that contact the spinning armature, while brushless DC motor has no physical contact between moving parts. Instead, a brushless DC motor has fixed magnets on the outside of the rotor that interact with the windings on the stator to create rotation.

Brushed DC motors are typically cheaper to manufacture but tend to break down over time. Brushless DC motors are becoming more popular, although some applications, such as power tools, still call for brushed motors. Assun Motors designs manufactures, and provides high-performance DC driving systems to help you power your applications. Our team can help you determine which type of motor is best for your needs.

How to Tell the Difference Between Brushless and Brushed Motor Physically?

If you have a DC motor, it can be difficult to tell the difference between a brushed and brushless motor. Here are some tips;

External Difference

Brushed motors will have physical brushes on the outside of the motor, while BLDC motors will not. Externally you’ll notice that the brushed rotor has permanent magnets glued or bolted to the outside. The permanent magnet has a north and south pole that work with the armature to create motion. The armature is the rotating part inside the motor.

On a BLDC motor, the armature is on the outside of the motor and the magnets are on the inside. The armature is what rotates, while the magnets are stationary. This is the main external difference between brushed motor and brushless motor design.

Internal Difference

A brushed motor appears to have two coils around the armature of the rotor, while brushless motors have tightly wound coils on the armature of the stator. With a brushed motor, you’ll notice that the armature is connected to the brushes. The brushes are what make contact with the spinning armature and help create motion. On a brushless motor, there are no brushes. The armature is still connected to the outside of the motor, but it doesn’t make contact with anything.

Instead, the armature interacts with the magnets on the inside of the motor to create motion. In addition, brushed motors have a commutator that helps reverse the current and keep the armature spinning. Brushless motors don’t have a commutator because the current is reversed electronically.

The commutator usually looks like a copper ring around the armature with segments that are insulated from each other. As the armature spins, the brushes make contact with the different segments and reverse the current. This keeps the armature spinning in one direction.

In addition, the coils on a brushed motor are usually larger and not as tightly wound as the coils on a brushless motor. This is because brushed motors have to be able to handle the sparks that occur when the brushes make contact with the commutator.

How to Tell the Difference Between Brushed and Brushless Motor Performance?

There are several performance differences between brushed motor and brushless motor.

Brushed motors are typically cheaper to manufacture, but they tend to have shorter lifespans and are less efficient than brushless motors. This is because the brushes in a brushed motor wear down over time and need to be replaced. In addition, the sparks that occur when the brushes make contact with the commutator can cause damage to the motor over time.

Brushless motors are more expensive to manufacture, but they tend to last longer and are more efficient than brushed motors. This is because there are no brushes in a brushless motor to wear down and no sparks to cause damage.

In addition, because they are so cheap to manufacture, brushed motors are usually found in toys, while brushless motors are usually found in higher-end applications such as power tools.

In Summary

To help summarize, below are the key differences between both brushless DC motors and brushed DC motors:

Brushed DC Motors:

• Have magnets located permanently on the outside of the rotor
• Have an armature that rotates on the inside, which is connected to brushes
• Brushes make contact with a commutator to keep the armature spinning in one direction
• Coils are larger and not as tightly wound
• Cheaper to manufacture, but have shorter lifespans and are less efficient
• Found in toys, tools, and other regular everyday items

Brushless DC Motors:

• Have magnets located permanently on the inside of the motor, around the stator
• Have an armature located on the outside that rotates
• The armature is what interacts with the magnets to create motion, there is no need for brushes
• Coils are smaller and more tightly wound
• More expensive to manufacture, but have longer lifespans and are more efficient
• Found in higher-end applications such as power tools, electric power vehicles, and aircraft.

The Bottom Line

Assun Motors offers coreless brushless and brushed DC motors which have a wide variety of applications. When selecting the right motor for your application, it is important to consider the required torque, speed, and power as well as brushless and brushed design. Explore our blog posts to help you find the best DC motor for your application today.

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