In essence, brushless and brushed motors do the same task. They generate rotating motion from electric current. Brushless motors were first produced in the 1960s because strong electronics made their design feasible, but brushed motors have been used for over 100 years.
The main distinction between brushless and brushed motors is that brushless motors are powered electrically, whereas brushed motors are powered mechanically. Although both brushless and brushed motors have their advantages and disadvantages, some still prefer brushless motors because they last longer.
This brushless vs. brushed motor comparison article peels back the curtain on the inner workings of these two power sources, revealing what to search for in a drill, pedestal machine, or impact driver.
Brushless Vs. Brushed Motor
Since a few years ago, brushless motors have predominated the cordless instrument drive in the commercial tool market. When discussing brushed vs. brushless motors, there are significant distinctions and repercussions. Magnets are the primary driving force behind all motor operations.
Magnets with opposing charges are drawn to one another. The fundamental principle of a DC motor is to maintain a continuous pull forward by maintaining the negative charge of the spinning piece's attraction to the stationary magnets. Permanent magnet DC motors are used in numerous motion control applications.
When torque, position, or speed need to be controlled, DC motors are frequently utilized because they make the implementation of control systems simpler than AC motors. DC motors can be divided into two categories: brushed motors and brushless motors. As their names suggest, DC brushed motors feature brushes that distribute the motor and make it spin.
Electronic control takes the place of the manual commutation function in brushless motors. Either a brushless or brushed DC motor can be used in several applications. The same laws of repulsion and attraction between permanent magnets and coils govern their operation.
Wound wire coils are used in DC motors to produce a magnetic field. These coils, which make up the "rotor" of a brushed motor, are free to move to drive a shaft. The coils are typically wound around in an iron core; however, there are brushed motors that are "coreless," meaning the winding is supported by itself.
"Stator" refers to the motor's fixed component. A fixed magnetic field is created using permanent magnets. These magnets are often placed outside the rotor, on the inner side of the stator. The four fundamental components of a brushed motor are the permanent magnets, commutator rings, brushes, and armature.
The device's exterior is made of stationary permanent magnets (the stator). A permanent magnetic field is produced if one is negatively charged and the other is positively charged. When power is provided, a coil or group of coils forms an armature and turns into an electromagnet.
The rotor, which is also the component that spins, is often constructed of copper; however, aluminum is another option. An electronic controller replaces the brushes and commutator in a brushless motor.
The stator consists of stationary electromagnetic coils outside, with permanent magnets acting as rotors and rotating on the inside. The controller gives each coil the amount of power necessary to draw the permanent magnet.
The controller can electrically move the charge and produce an opposite charge to the permanent magnet. This pushes the permanent magnet because like charges repel one another. The rotor is now rotating due to a push and a pull.
A magnetic field drawing the magnets in is produced when power is delivered to the electromagnet inside the armature. The armature revolves in a circle of 180 degrees. It is necessary to switch the poles in order to keep the electromagnet spinning.
The brushes manage polarity shifts. They establish contact with the two revolving electrodes of the armature; the electromagnet revolves with its magnetic polarity reversed. The speed and torque can be changed to provide a steady velocity or a speed that is inversely related to the mechanical force by modifying the magnetic field's voltage level or strength.
The motor windings that control the motor's torque and speed receive current pulses from the controller. The commutator and brushes experience mechanical wear throughout the motor because there is mechanical friction between them since, as an electrical contact, they are typically unable to be lubricated.
The motor will eventually stop working as a result of this wear. Large brushed motors often include replaceable brushes made of carbon intended to retain good contact over time. Periodic maintenance is required for these motors. Also, with replaceable brushes, the commutator eventually wears out.
When DC voltage is placed across the brushes of a brushed motor, current flows along the rotor windings and causes the motor to spin. Brushed motors have many drawbacks besides being affordable, dependable, and having a high torque to inertia ratio.
The brushes on this kind of motor need to be cleaned or changed regularly. Due to rotor restrictions, electromagnetic interference, limited maximum speed, and high rotor inertia brought on by arcing on the brushes.
A brushless motor does not have a physical commutator but still has an armature, stator, and rotor. It does not have any brushes either, as the name would imply. The electronic circuit known as an inverter is used to replace these components. This generates a single magnetic field that revolves continually around the frame to produce motion.
Therefore, neither the accompanying commutator nor the actual contact of brushes is required for this sort of motor. An electric motor running on direct current and lacking the commutator of a typical brush motor is known as a brushless motor. Although the upfront costs are higher, it provides clear advantages over brush motors and is ultimately more affordable.
Numerous trenchless building applications use brushless motors. Today's brushless motors combine wider working speed ranges, higher output power, improved heat dissipation, smaller size, efficiency, and exceptionally low electrical noise to solve many of the shortcomings of brushed motors.
Since brushless motors lack electrical connections that could break, they are more reliable and require less maintenance more frequently in industrial and commercial settings.
Difference Between Brushed And Brushless Motors
Caused by power losses from friction and energy transfer through its commutator mechanism, brushed motors are pretty inefficient. Conversely, they are more effective because brushless motors do not experience the mechanical losses that brushed motors do.
Due to its design, brushed motors last less time since the brushes become damaged more easily. Depending on the working environment and operational temperatures, they need to be replaced anywhere between every two and seven years. Brushless motors require less general maintenance since they lack physical commutators and brushes.
Speed control techniques for brushed motors must be more intricate. Lowering the voltage decreases the motor's torque, yet doing so results in significantly slower speeds. Controlling brushless motors is comparatively easy. Because of this, brushless motors tend to have higher torque at slower speeds.
Generally, brushed motors operate at speeds that are too high to be useful. They frequently need a gearing mechanism to decrease speed and hence boost torque because of this. However, brushless motors thrive in this area, typically utilized without gearing. Gearing may be used if a particular application needs additional torque or very high precision.
For some applications, brushless motors are safer, lighter, more resilient, and more effective. They move much more silently as well. In locations with a potential for an explosion, brushed motors can produce sparkles, which is not desirable. Due to this, brushless motors are frequently chosen as the best option in dangerous working environments.
In conclusion, brushless motors are superior to brushed ones. This is because they offer longer operating times, more power, and improved reliability for cordless equipment. However, they cost more money, need less user upkeep, and offer low energy efficiency for corded instruments.
Shawn Manaher loves to play with new toys and dive into new hobbies. As a serial entrepreneur, work definitely comes first but there is always room for hobbies.