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Have you ever wondered how a dc brushed motor works? If you’ve been carrying out a project that requires movement, you’ll most likely need a motor. DC brushed motors utilize in many applications, from electric vehicles to robotics. But how do they work?
This post will take an in-depth look at the mechanics of a dc brushed motor. We’ll discuss how it operates, how to troubleshoot common problems, and more. So, whether you are a business owner who wants to learn more about motors for your products or just curious about how they work, continue reading to learn more.
How Does a DC Brushed Motor Works?
DC motors are direct-current electric motors. Fast starting torque and high speeds are among its features. The DC brushed motor is the most common and simplest type of motor, and this sort of motor is everywhere. Your phone’s vibration feature is most likely powered by one. Most toys, everything with a vibration motor, and popular tools like cordless drills utilize brushed DC motors.
So, how does a DC brushed motor works? A DC motor has two main parts, the stator and the rotor. And the other parts include armatures or windings, shaft, commutator, and brushes. Let’s take a look at these parts and how each one works.
▶Stator and Rotor
The stator is the stationary part of the motor, and the rotor is the rotating part. The stator houses the motor’s field windings. These are usually made of copper or aluminum, creating a magnetic field. The rotor contains permanent magnets that interact with the stator’s magnetic flux to create torque, turning the rotor.
The stator’s magnetic field generates either passing current through the windings or using permanent magnets. The most common method is to pass current through the windings because it allows more control over the motor’s speed and torque.
▶Windings/Armatures
The armatures, or windings, are the wire coils wrapped around the motor’s iron core. These are what create the magnetic field when the current passes through them. The number of armatures winding around the stator’s core will determine how much torque the motor can produce. There are at least 3-wire windings attached to metal plates called armatures in the center of the motor, connecting to the motor shaft.
▶Motor Shaft
The motor shaft is what connects the rotor to the load. The load is the device that the motor is powering, such as a drill bit or a fan blade. The shaft also has windings, which interact with the stator’s magnetic field to create torque and make the rotor turn. The shaft connects to armatures in the center of the motor.
▶Commutator
The commutator is a ring of copper or aluminum that the armatures are connected to. The commutator’s job is to reverse the current flowing through the armatures so that they can keep turning in the same direction.
▶Brushes
The brushes are made of carbon and sit on either side of the commutator. They contact the commutator and allow current to flow through it. The brushes also cause the motor to make a buzzing sound when it is running. Brushes come into direct touch with the commutator. Then, a DC voltage delivers towards the brushes, which is then passed to the commutator and activates the windings. The armature is surrounded by a magnetic field created by the input power.
The armature’s left side moves towards the right stator magnet and the left magnet on the left side. Then, the armature’s right side is then pushed to the left, away from the right magnet. The motor shaft produces to revolve by continually switching the polarity of the magnetic field surrounding the armature.
The armature constantly rotates between the opposite stator poles, activated by the brushes. The result is a continuous rotation of the motor shaft.
It is how a DC brushed motor works and how it can convert electrical energy into mechanical energy.
The DC Brushed Motor Types
There are 5 common types of DC brushed motors, which are:
⓵Brushed Separately Excited Brush Motor
A separately excited brushed DC motor is one where the field windings are not part of the armature winding circuit. The current flowing through the field windings is supplied by a separate DC power source, usually a battery or rectifier. This motor applies when speed and torque need to be controlled independently.
⓶Brushed Permanent Magnet Brush Motor
As the name suggests, a permanent magnet brushed DC motor is one where permanent magnets replace the field windings. The external field current is not required because of the permanent magnet. This design results in a Brush DC Motor that is lighter, smaller, and has low energy consumption, and it is the type of DC Brushed Motor that carries Anaheim Automation.
⓷Brushed Series Wound Motor
A series wound DC motor is one where the armature and field windings are connected in series. It automatically changes speed in response to load, rising as load decreases. When there is a high need for power, this series wound motor is typically limited.
⓸Brushed Shunt Mount Brush DC Motor
A shunt-wound brushed DC motor is one where the armature and field windings are connected in parallel. The speed of this type of motor can be controlled by varying the armature current. They are also less expensive to manufacture than other types of motors.
Despite the overall load, the brushed shunt-wound Brush DC Motor would operate consistently.
⓹Brushed Compound Brush DC Motor
These DC brushed motor combines brushed series-wound motors and a brushed shunt. This type of motor has high starting torque and good speed regulation. Because the series field is used to create a strong magnetic field, the shunt field can be weaker. These brushed compound motors are often utilized if extreme starting conditions and steady speed are required.
Due to its simplicity and efficiency, the Brush DC Motor is a popular choice in the automobile sector. Many car companies use them for electric windows, seats, and other features. The Brush DC Motor, on the other hand, maybe found in practically every sector, from manufacturing to electronics.
The Pros and Cons of DC Brushed Motor
Among the oldest electrical motor concepts is the DC Brushed Motor. The DC Brushed Motor is the most popular for the large majority of the variable speed and torque control applications. There are several reasons for this, but there are also some drawbacks that should be considered. There are advantages and disadvantages of using a DC brushed motor, and we will discuss them below.
The Pros of DC Brushed Motor
👍Inexpensive
Due to their simple design, DC brushed motors are less expensive than other types of electric motors. When compared to AC induction motors and servo motors, for example, the cost of a DC brushed motor is significantly lower.
👍High Torque at Low Speeds
DC brushed can produce high torque at low speeds. It makes them ideal for applications where starting torque is important, such as in automotive applications.
👍Easy to Control
In order to make the motor turn, just provide a DC voltage. The motor will rotate faster if the voltage (or PWM duty cycle) is increased. The direction of rotation is reversed when the polarity is reversed. Brushed DC motors may be powered without needing a microprocessor by simply attaching it to a battery. It makes them ideal for applications where precise control is required.
Also, there are no brushes to replace and no commutators to clean, which means that once a DC brushed motor is up and running, it will continue to run with little intervention.
The Cons of DC Brushed Motor
👎Brushes Wear Out
The biggest disadvantage of DC brushed motors is that the brushes will eventually wear out. The brushes contact the commutator, and as they spin, they slowly erode. When the brushes get too short, they will no longer contact the commutator, and the motor will stop working.
👎Reversing polarity can Damage the Motor
Another disadvantage of DC brushed motors is that reversing the polarity can damage the motor. It is because the current flow through the brushes is reversed, and this can cause sparking, which can damage the commutator.
👎Vulnerable to Dust and Debris
Another problem with DC brushed motors is that they are vulnerable to dust and debris. The brushes and commutator are exposed, which means that they can be damaged by dust and debris. It can cause the motor to stop working or even catch fire.
Despite the disadvantages, DC brushed motors are still widely used because of their advantages. They are simple, efficient, and inexpensive, making them ideal for various applications.
Brushed Vs. Brushless Motors
Brush and brushless motors are the two most common types of DC motors. The main difference is that brushless motors don’t have brushes, while brushed motors do.
Brushless motors are more efficient than brushed motors because they don’t have the friction and electrical losses associated with brushes. They also last longer because there are no brushes to wear out.
Brushless motors, like brushed motors, function by switching the polarity of internal windings. It’s an inside-out brush motor that doesn’t need brushes.
The most common type of brushless DC motor is the inner-rotor design. The stator is on the inside, and the rotor is on the outside. This design is more efficient because it reduces magnetic losses.
🔵Cost
It is usually the biggest factor when deciding between brushed and brushless motors. Brushed motors are less expensive since brushless motor requires additional electronics to control the motor. Brushless motors are easier to make than brushed motors because they don’t have a commutator or brushes, although brushed motor technology is fairly established and production prices are reasonable.
🔵Torque Ripple & Acoustic Noise
Brushed DC motors have a torque ripple because the brushes make contact with the commutator unevenly. It causes a pulsating force that results in vibration and noise. The amount of torque ripple depends on the number of poles, brush material, and brush geometry.
Brushless DC motors don’t have this problem because there are no brushes. The magnets are attached to the rotor, which rotates around the stator. It results in a smoother force and less vibration and noise.
🔵Electrical Noise
Brushed DC motors create electrical noise because the brushes contact the commutator. It causes sparking that can be disruptive to electronic equipment. Brushless DC motors don’t have this problem because there are no brushes.
🔵Acceleration and Speed
Brushed DC motors have a high starting torque, which means they can accelerate quickly. They also have a high speed, making them ideal for high speeds applications.
Brushless DC motors don’t have as high starting torque as brushed motors, but they make up for their inefficiency. They are more efficient because there is no friction or electrical losses associated with brushes. Additionally, brushless motors can reach higher speeds because they don’t have a commutator.
🔵Lifetime
DC brushed motors have a shorter lifetime than brushless DC motors because the brushes wear out. The brushes also create sparks that can damage the commutator. Brushless DC motors don’t have these problems because there are no brushes or commutators. It makes them more durable and longer-lasting.
🔵Applications
DC brushed motors are used in various applications, such as toys, power tools, and appliances. They are also used in automotive applications, such as windshield wipers and power windows.
Brushless DC motors are used in high-end applications that require high speeds and high torques. These include electric vehicles, hard disk drives, and computer printers. They are also used in industrial applications, such as pumps and fans.
Both brushed DC motors and brushless DC motors have their advantages and disadvantages. It is essential to consider the specific application before deciding which type of motor to use.
Tips on How to Care for Your DC Brushed Motor
📌Inspect the Brushes Regularly
The brushes are the most crucial part of a DC brushed motor. They are responsible for transferring electricity to the rotating commutator. Over time, the brushes will wear out and need to be replaced. It is essential to inspect the brushes regularly to ensure they are in good condition.
📌Make an Auditory Inspection
During routine operations, make sure to watch out for noises or vibrations. A sound coming from the motor’s electrical or mechanical components indicates imbalances or misalignments, loose windings, or worn bearings. Items trapped in the vents or shroud might be detected through vibrations. Constant vibrations could also cause overheating and brush sparking.
📌Keep Commutator and Brush in Excellent Condition
A well-maintained commutator will prolong the life of your DC brushed motor. The commutator should be free of dirt, grease, and debris. It is also essential to check the brush regularly. The brush should be free of excessive wear and tear.
Frequently Asked Questions
Q: How to control a DC brushed motor?
The voltage applied towards the armature controls the brushed DC motor’s speed, while the armature current controls the torque. Separately controlling the torque and flux is simple. You need a separate power supply for the field winding. It is the fundamental premise that all current control approaches are based on.
Q: What are the applications of a DC brushed motor?
Common applications for brushed DC motors include automotive, such as windshield wipers and power windows. They are also used in industrial applications, such as pumps and fans. Additionally, they are used in various consumer applications, such as power tools and appliances.
Q: What is the average lifespan of a brushed motor?
The life of the brushed motor is dependent on the brush type. The average lifespan of a brushed motor is about 1000 up to 3000 hours. However, with proper maintenance, the motor’s life can be extended. It all boils down to how you take care of your motor.
Q: Is the DC brushed motor worth the money?
The answer to this question depends on your needs. If you need a durable and long-lasting motor, a brushless DC motor might be a better option. However, if you need a less expensive motor and easier to control, a DC brushed motor might be better. Ultimately, it all comes down to what you need and what you are willing to spend.
Q: How do I know if my DC brushed motor is bad?
There are a few signs that indicate a bad DC brushed motor. These include noise or vibrations coming from the motor, excessive wear and tear on the brushes, and a dirty or damaged commutator. If you notice any of these signs, it is essential to take action right away to prevent further damage.
Q: How often should I replace my DC brushed motor?
It’s necessary to replace the brush when 1/4th of its original length has worn down. If you ever need to change the brushes, be sure they’re the motors’ right size, style, and quality. This information is usually found in the owner’s handbook. Also, always follow the manufacturer’s recommendations.
Q: Can I fix my DC brushed motor myself?
In some cases, you might be able to fix your DC brushed motor yourself. However, it is essential to consult the owner’s manual or an expert before attempting any repairs. Repairing a motor without proper knowledge or expertise can cause further damage.
Bottom Line
Now that you know how a DC brushed motor works, you can better understand the mechanics behind this type of motor. With this knowledge, you can decide whether or not a DC brushed motor is suitable for your needs. In addition, keeping your dc brushed motor in an excellent working condition by following the tips above can help to prolong its lifespan.
Do you have any questions about how a DC brushed motor works? Leave a comment below and let us know!
