Brushed Dc Motor Basics

 

A Brushed DC Motor is a type of motor invented in the 19th century that is still widely used in several fields today. As one of the earliest motors to be applied in history, it has the characteristics of simple structure, low cost and easy control.

 

The working principle of Brushed DC Motor depends on the fit of stator and rotor. Fixed permanent magnets or electromagnets are mounted on the stator to provide a constant magnetic field. The rotor is equipped with armature winding and commutator, and the end cap is installed with a brush or carbon brush. The brush and commutator work together to change the flow direction of the current in the rotor winding, thus driving the rotor to continue to rotate and realize the conversion of electrical energy to mechanical energy.

 

Although with the advancement of Motor technology, new motors such as brushless DC motors have gradually occupied a larger market share, Brushed DC Motor still remains competitive in many fields with its simple design and low cost. They are especially suitable for occasions where the control requirements are not high, such as home appliances, power tools and automotive starting systems. These advantages ensure the continued application of Brushed DC Motor in modern industry.

 

 

In the field of motors, Brushed DC Motor and Brushless DC Motor are two common types of motors. They differ significantly in terms of structure, efficiency, longevity, control, and cost.

 

1. In terms of structure

The structure of Brushed DC Motor is more traditional, the stator is usually installed with permanent magnet or electromagnet, the rotor is equipped with armature winding and commutator, brush or carbon brush is used to contact with the commutator to achieve the commutation of current. This design leads to wear problems with the brush and commutator, which require regular maintenance.

 

Brushless DC motors, on the other hand, have a more advanced design without brushes and commutators. It uses an electronic controller to achieve the commutation function, by controlling the electronic signal to change the direction of the current, thereby driving the motor to rotate. Because there are no mechanical wear parts, brushless motors are more reliable and compact.

 

2. In terms of efficiency and longevity

Brushed DC Motor efficiency is relatively low, the main reason is that the friction between the brush and the commutator will produce heat and energy loss. At the same time, the brush will gradually wear with the increase of use time, affecting the performance of the motor and shortening the service life.

 

Brushless DC motor because there is no friction of brush and commutator, the efficiency is significantly higher, and the energy conversion loss is small. Coupled with the design without mechanical wear, the service life is also longer, suitable for the occasion of long-term continuous operation, and the maintenance demand is low.

 

3. Control and cost

The control of Brushed DC Motor is relatively simple, usually only need to control the power supply to achieve the basic speed adjustment and rotation direction, suitable for the application of control accuracy requirements are not high. Because of its traditional design and low manufacturing cost, it is the first choice for many low-cost equipment.

 

Brushless DC motors, while more efficient, are more complicated to control. It relies on electronic controllers to adjust the speed and direction of rotation of the motor, which allows brushless motors to achieve more precise control, especially in the need for precise speed regulation and torque control. However, this electronic control system increases the cost, resulting in the overall cost of brushless DC motors being higher than that of brushed motors.

 

 

As a classic Motor type, Brushed DC Motor has been gradually replaced by brushless DC motor with the progress of technology, but its unique advantages make it still competitive in many applications.

 

1. Simple construction

Brushed DC Motor has a very simple design structure. It consists of basic components such as stator, rotor, brush and commutator. Since there is no complicated electronic control system, this simple structure makes the brush motor easy to manufacture, assemble and maintain, especially for occasions where the complexity of the motor design is not high.

 

2. Low manufacturing cost

Due to the simple structure, relatively few materials and processes are required to manufacture Brushed DC Motor, which makes its production cost significantly lower than other motor types, especially brushless motors. This feature makes it ideal for many price-sensitive devices.

 

3. Have high starting torque

Brushed DC Motor has a large starting torque, can provide enough power at low speed or even at rest. This makes it ideal for applications that require high starting torque, such as power tools and some industrial equipment.

 

4. Wide range of speed adjustment

By simply adjusting the input voltage, Brushed DC Motor can operate in a large speed range, and can adjust the speed smoothly. This wide range of speed adjustment capabilities makes it of great application value in equipment where speed flexibility is required.

 

5. Ease of commutation

Brushed DC Motor through the brush and commutator to achieve commutation, the operation principle is simple, do not need complex electronic control system when working. This makes it very effective in application scenarios that require fast response and frequent commutation, and especially performs well in environments that do not require precise control.

 

6. Suitable for sudden reversals and speed changes

Brushed DC Motor has the ability to reverse direction and adjust speed quickly, which makes it useful in applications that require a quick change of operating state. For example, in automation equipment, the need for frequent motor reversals and fast speed changes can be achieved through the simple control of the brushed motor.

 

 

Although Brushed DC Motor performs well in many applications, it also has some disadvantages that make it inferior to other motor types in some occasions.

 

1. Brush and commutator wear and tear

A significant disadvantage of Brushed DC Motor is the wear of the brush and commutator. As time goes by, the brush will gradually wear out from friction, resulting in reduced motor performance and possibly even failure. This wear can affect the efficiency and output of the motor, increasing the frequency of repair and replacement.

 

2. Generate electrical sparks

When the brush is in contact with the commutator, a Brushed DC Motor will produce an electrical spark due to the switching of friction and current. This not only affects the stability of the motor, but may also cause electrical failure, causing damage to the circuit and other components. In addition, the generation of sparks may cause safety hazards in some sensitive environments.

 

3. Electromagnetic interference and noise

Brushed DC Motor will produce electromagnetic interference and noise due to the contact between the brush and the commutator during operation. This interference may affect surrounding electronics, resulting in signal distortion or equipment failure. At the same time, the noise of the motor itself can affect its suitability in certain applications where noise requirements are strict.

 

4. High maintenance requirements

Due to the wear nature of brushes and commutators, Brushed DC Motor requires regular maintenance to replace worn brushes and clean commutators. This high maintenance requirement makes the total cost of its long operation increase, especially in the case of limited resources for maintenance, which can become a significant problem.

 

5. Short life span

A Brushed DC Motor has a shorter life than a brushless DC motor. The wear of the brush and commutator will directly affect the service life of the motor, especially in the application of high load and frequent start-stop, the wear speed will be accelerated. Therefore, in the need for a long time of operation, the brush motor may not be the best choice.

 

 

The working principle of a Brushed DC Motor is based on electromagnetic induction, which converts electrical energy into mechanical energy through the interaction of the stator and rotor.

 

1. The stator generates a magnetic field

In Brushed DC Motor, permanent magnets or electromagnets are usually installed on the stator. When the motor is energized, the stator generates a constant magnetic field, which provides the rotor with the direction of motion and the basis for force.

 

2. Run an electric current through the rotor

The rotor is the rotating part of the motor with armature windings installed inside. When the current passes through the brush into the rotor windings, an electromagnetic field is created inside the windings that interacts with the stator's magnetic field. The direction in which the current flows through the winding is constantly changing through the interaction between the brush and the commutator, ensuring that the rotor can continue to rotate.

 

3. Magnetic field interaction

The interaction between the stator's magnetic field and the rotor's electromagnetic field drives the rotor to rotate. In this process, the role of the commutator is to switch the current direction regularly to ensure that the rotation direction of the rotor remains the same, and complete the conversion of electrical energy to mechanical energy, so as to realize the work of the motor.

 

 

Brushed DC Motor because of its simple structure, low manufacturing cost, easy to control the characteristics, widely used in all kinds of daily equipment and industrial applications, especially for the occasions that do not need complex control. The following are some typical application areas (including but not limited to) :

 

Hair dryer

A Brushed DC Motor in the hair dryer drives the fan blades to rotate and blow out the strong airflow. Since the hair dryer does not require much precise control, the high speed and high torque of the brushed motor are ideal for this application.

 

Electric Drill

Power tools such as electric drills need to provide high torque when starting, and Brushed DC Motor with its large starting torque and wide range of speed adjustment make it ideal for such tools to ensure that drilling and cutting work goes smoothly.

 

Electric toys

Electric toys such as remote control cars and robots often use Brushed DC Motor. This type of motor has a simple structure and is able to provide enough power for toys while keeping manufacturing costs low, making it the first choice for the toy industry.

 

Electric toothbrush

A small Brushed DC Motor in an electric toothbrush drives the brush head to rotate or vibrate to help the user clean their teeth. Since electric toothbrushes require less precision from the motor, the cost advantages of brushed motors are reflected in such products.

 

Small Household Appliances

Small appliances such as blenders, juicers, and vacuum cleaners often rely on Brushed DC Motor power. They exhibit efficient working capabilities and simple maintenance needs in these applications, making them an affordable option.

 

 

With years of industry experience since its inception in 2011, VSD is committed to providing reliable motor solutions for a wide variety of applications. Whether it is for home appliances, power tools, or automotive and industrial equipment, VSD always adheres to the philosophy of quality first, ensuring that every motor can meet the needs of customers. As experts in the field of Brushed DC Motor, we are constantly innovating to adapt to the rapid development of modern industry. If you are looking to find the most suitable motor solution for your product, VSD will be your ideal partner.