Brushless Vs Brushed Motor: The difference You should Know

A power drill is designed to convert electrical power into mechanical motion. The market of power drills is filled with various options of motors that can handle multiple applications and varying power requirements and the most common type of motors include brushless or brushed motor. However, they are based on the same physical principles, their structure, performance, and control vary significantly.

Any motion control expert should understand the difference between brushed and brushless motors. Brushed motors were once quite common. Though their brushless counterparts have mainly supplanted them, the right DC motor of either type can make a project far more well-organized.

Here we will let you know what differentiates the DC motors from one other. The basic work principles behind both types of DC motors will be discussed in detail, and then will be compared to show where each machine functions best in industry.

Brushed Motor

Brushed motors are the oldest electric motor and use DC with mechanical commutation to produce mechanical energy. As their name implies, these motor uses brushes to link the DC power supply to the rotor assembly, which is the motor component consisting of the armature, commutator rings, and output shaft. Carbon brushes are selected according to the brand and type of tool. They are fitted on the fixed part of a motor to ensure optimal transmission of power to the rotor, known as the rotating part. They provide switching without the spark, while in some cases, the brushes are mounted on a brush holder incorporating a spring that is specially made to boost thrust. Keep in mind that the manufacturers of any portable power tools, including drills, typically sell brushes that are compatible with their respective machines.

Brushless DC Motors

With contrast to brushed motors, these motors do not generate motion using brushes. They work by taking the permanent magnetic field usually that is housed in a brushed stator of motor and place it around the rotor in the form of actual magnets. While its build is simple, these brushless motors need electrical commutation, instead of the mechanical commutation found in brushed motors. Though electric communication increases the complexity but at the same time, it also diminishes brush maintenance, friction damage, and unwanted vibration/noise often found in brushed motors. 

Brushless motors have a high dynamic response, and run at many different speeds, making them especially suited for continuous, speed-controlled applications, thus are quite efficient. 

Comparison of Brushed and Brushless Motors

We have equipped you with some necessary information about these two DC motors. This part of the guide will tell you the real difference between these two.

To make this article interesting and easy to read, we have list down the difference in the form of the table. This table will include almost all the significant characteristics and then are compared with each other. This table will show the comparisons but note that they are entirely generalized, as both types of motors come in various sizes, and are therefore numerically tough to compare. 

Have a look!

CharacteristicsBrushed MotorsBrushless Motors
LifetimeAverageLong
CostLowHigh
ComplexitySimpleComplex
Power-DensityAverageHigh
Speed curveModerately flat/linearFlat/Linear
EfficiencyAverageHigh
Speed RangeLowHigh

The complexity of brushless motors will increase with its working characteristics and as well as their cost. By looking at this comparison table, you can see that brushless motors trump the brushed motors in almost every feature, it is because they implement complex electrical controllers which radically increase their price. The speed curve of the brushless motor shows the torque response with relation to the speed. We have already mentioned in the table that the curve is straight and linear, which means that the torque varies linearly with speed because their electrical commutation generates more precise velocity and gives more torque control. When we talk about the power density, it means we are relating to rated power which is in HP or kW, compared to its geometric volume. This value is essential for those who need high torque in small packages. As compared to brushed motors, the brushless motors provide a high torque that can be sustained more effectively.

Brushed motors usually come with brushes with brush life so that the operator knows when they have to replace them since brushed motors use mechanical commutators and brushes. Hence, there is a possibility of sparking as well as breakdown, which decreases the lifespan. While on the other side the brushless motors can last longer because there is no friction or requirement for periodic maintenance, so no risk for sparking. You can also increase the lifespan of brushed motors by frequent preventive and scheduled maintenance checks, but these can be tedious as well. While when both motors are compared, the brushless motor has less risk for failure.  

You might be thinking that brushed motors are simply the worst options, and your assessment would be justified if it were not for the price. Yes, you are right because brushed motors are not just cheaper per unit, but their installation costs are also relatively low. One of the reasons for brushed motors being reasonable in price is they do not call for electrical control systems, which are often more expensive than the brushless motors that require them. So, while where brushless motors give us more benefits they do so at a very literal cost. If cost is an essential specification for you and it should always be, brushed motors should be considered first, before looking into brushless designs. 

Conclusion

Brushless motors are no doubt better than brushed motors in many aspects and any power tools with a brushless motor are now considered as high-end products. But still, as a consumer, you can take benefit of reduced maintenance, improved efficiency, reduced heat and noise.

Both of the DC motors are invaluable in the product from computers, automobiles, toys, manufacturing, and more, so there are good choices when looking for any DC motor. You just have to make sure that you understand the benefits and as well as the risks of working with either of these machines and also consider the project’s specifications to determine which suits you the best. 

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