A DC motor or a Direct Current motor is an electric machine that works by converting electrical energy into mechanical energy.
This process starts when the DC motor takes up electrical energy from the direct current supply and then converts that energy into mechanical energy or rotation.
The magnetic fields that are formed are used for bringing motion into the rotor. A DC motor has two types: Brushed and Brushless.
Key Takeaways
- Brushed motors use brushes to transfer electric current to the rotor, while brushless motors use electronic controllers to regulate current to the motor windings.
- Brushed motors have a shorter lifespan due to the wear and tear of the brushes, while brushless motors are more durable and efficient.
- Brushed motors are less expensive and simpler in design compared to brushless motors.
Brushed Motor vs Brushless Motor
The difference between Brushed and Brushless Motors is that a brushed motor uses a two-pole electromagnet as its external rotor, whereas a brushless motor uses a permanent magnet for the external rotor. In a brushed motor, the commutator takes care of the polarity of the electromagnet. While in a brushless motor, three phases of driving coils and a special sensor track the rotor’s position.
A brushed DC motor utilizes wound site coils known as the armature, which functions as an electromagnet. It is used as an external rotor. The direction of the current is reversed twice per cycle by the commutator.
It also works for reversing the polarity of the electromagnet when it crosses the permanent magnet. This forms the direct current, which later gets converted into mechanical energy.
On the other hand, a brushless DC motor uses a permanent magnet on the rotor. It has an electrical method of turning the rotor.
Brush electrodes are not used here, unlike the brushed motor. The working principle of the brushless motor is just the reverse of the former. Electromagnets are used for spinning the motor.
Comparison Table
| Parameters of Comparison | Brushed Motor | Brushless Motor |
|---|---|---|
| Launch | The brushed motor got launched in the late 1800s. | The brushless motor got launched in the 1960s. |
| Composed of | A brushed motor contains a physical commutator for the rotor. | A brushless motor lacks brushes and runs electronically. |
| Efficiency | It is less efficient because of power losses. | It is more efficient. |
| Lifespan | It has a shorter lifespan. | Its lifespan is longer. |
| Torque | Torque is lowered at low voltage. | Torque remains higher. |
| Gearing | It requires gearing as it runs very fast. | No need for gearing. |
| Features | It is heavier in comparison. | It is lighter and reliable. |
| Pricing | It is cheaper. | While it is priced at higher rates. |
What is Brushed Motor?
A brushed motor is an electric motor that uses direct current to do the required work. It uses an armature, which functions as an electromagnet. This is used on the external rotor.
There is a physical commutator for turning the rotor on. The poles of the electromagnet rub back and forth against that of the permanent magnet, which gradually forms a direct current.
Brushed motors have been in use since the late 1800s. They are highly preferred for commercial and industrial usage.
There are four basic components in a brushed motor: the stator, the rotor, the brushes, and the commutator. The speed of the motor can be adjusted by changing the voltage amount of the magnetic field strength that is formed within them.
Brushed motors have zinc and pressed steel coating on them, along with a cap made up of plastic fixed at one of the ends. The coating and cap have quite a few holes in order to facilitate airflow, although the motor for preventing it from overheating.
Screw holes are also present for fixing the motor in position. The cap also contains connection pins that come in pairs for the power supply connection.
Brushed motors are widely used in households. For example, electric toy cars, electric toothbrushes, bread slices, etc., utilise a brushed motor.
Other machines, such as cranes, mills, drills, etc. that are required for outdoor activities also make use of this motor.
What is Brushless Motor?
A brushless motor is another type of DC motor. It also uses direct current for its functioning. As the name suggests, a brushless motor does not have brush electrodes. Instead of a physical commutator, it is equipped with an electronic commutator.
They follow the reverse working principle of brushed motors. Permanent magnets are used on the rotor, while controllable electromagnets are used for spinning the rotor.
Brushless motors were introduced in the 1960s. They have low maintenance requirements and are highly efficient. The level of control in them is also excellent.
They come in two forms: Inrunner, where the stator is on the external part of the rotor, and Outrunner, where the stator is on the internal part of the rotor. As there are no brushes, a small circuit board is used as an alternative.
For the working of the motor, the electromagnet coils are turned on and off consecutively. This is done to magnetize them temporarily to attract or repel the permanent magnets.
In brushless motors, the amount of torque remains high even at low voltage. Torque is produced by misalignment of magnetic fields of the stator and rotor.
Brushless motors have a longer lifespan. They are preferred in devices that require continuous motion regularly.
Air Conditioners, Washing Machines, Fans etc., are some of the devices that make use of this motor. These motors are also found in electric vehicles.
Main Differences Between Brushed and Brushless Motors
- Brushed motors have brushes, while brushless motors do not.
- Brushless motors are more efficient in comparison.
- Brushed motors are heavier and have a shorter lifespan.
- Only the brushed motors require gearing.
- Brushless motors are more expensive than brushed motors.
- At low voltage, the torque in a brushed motor is lowered, while the torque in a brushless motor remains higher.
- https://trs.jpl.nasa.gov/bitstream/handle/2014/42161/NASA_CP-2012-217653.pdf?sequence=1#page=15
- https://ieeexplore.ieee.org/abstract/document/4159575/
Last Updated : 18 August, 2023
I’ve put so much effort writing this blog post to provide value to you. It’ll be very helpful for me, if you consider sharing it on social media or with your friends/family. SHARING IS ♥️
Piyush Yadav has spent the past 25 years working as a physicist in the local community. He is a physicist passionate about making science more accessible to our readers. He holds a BSc in Natural Sciences and Post Graduate Diploma in Environmental Science. You can read more about him on his bio page.
The article provides a comprehensive overview of brushed and brushless motors. It’s great to see such valuable technical information explained clearly.
Absolutely, the clarity of the explanations makes this a very useful resource for anyone interested in engineering or electric machines.
A wealth of knowledge presented here, from historical background to operational differences. Impressive article.
The article offers a thorough exploration of brushed and brushless motors, providing a well-structured comparison that aids in understanding these essential electrical devices.
I couldn’t agree more. The structured comparison enhances the article’s educational value and practical relevance.
I found the detailed comparison table between brushed and brushless motors very helpful. It makes it easier to understand the advantages and disadvantages of each type.
I completely agree. The clarity of the information presented in the table is commendable.
While the article offers valuable insights into the differences between brushed and brushless motors, it could benefit from more real-world examples of applications for each type of motor.
I understand what you mean. Incorporating practical examples would enhance the article’s educational value.
Very informative article about DC motors and their mechanisms. Love the detailed comparison between brushed and brushless motors, as well as the applications of each.
Yes, the in-depth explanation of the working principles and applications of these motors is quite fascinating.
The article’s detailed description of brushed and brushless motors, along with their applications, serves as a valuable educational resource.
Absolutely, the educational value of this article is commendable. It covers a wide range of technical aspects in an accessible manner.
I found the article’s focus on practical applications of these motors very insightful. It emphasizes the real-world relevance of the topic.
The explanations provided for how brushed and brushless motors work are clear and accurate. I particularly liked the historical context and the technological advancements described.
Indeed, the historical background adds depth to the understanding of these motor types. Well-written article.
I appreciate the distinction between brushed and brushless motors in terms of efficiency and lifespan. Very enlightening read!
Absolutely, understanding the trade-offs between different motor types is crucial, and this article does a great job explaining these factors.