News Center

Comparison of Brushless Motor and Brushed Motor

1. The difference between brushless motor and brush motor


The brushed motor includes four basic components: permanent magnets, armatures, commutating rings and brushes. The permanent magnet constitutes the exterior of the mechanism and does not move (stator). One is positively charged and the other is negatively charged, creating a permanent magnetic field. A brushed motor is a rotating electric machine that converts electrical energy into mechanical energy (electric motor) or converts mechanical energy into electrical energy (generator) with a built-in brush device. The brush motor is the basis of all motors. It has the characteristics of fast starting, timely braking, smooth speed regulation in a large range, and relatively simple control circuit.



The brushless DC motor is composed of a motor body and a driver, and is a typical mechatronic product. Since the brushless DC motor runs in a self-controlled manner, it will not add a start winding to the rotor like a synchronous motor that is started under heavy load under variable frequency speed regulation, nor will it cause oscillation and loss of step when the load changes suddenly. The permanent magnets of medium and small capacity brushless DC motors are now mostly made of rare earth neodymium iron boron (Nd-Fe-B) materials with high magnetic energy levels. In a brushless motor, you lose the commutator and brushes and gain an electronic controller. The permanent magnet now acts as a rotor and rotates inside, while the stator is now composed of an external fixed electromagnetic coil. The controller supplies power to each coil based on the charge required to attract the permanent magnet.


Generally speaking, brushless motors are more efficient than brushed motors, because brushless motors require electronic communicators and are therefore more costly.


1. Comparison of the characteristics of brushless motors and brushed motors


Disadvantages of brushed motors


2. High friction and high loss


After using the brushed motor for a period of time, it is necessary to open the motor to clean the carbon brush of the motor, which is troublesome and waste time.


3. High heat and short lifespan


Due to the structure of the brush motor, the contact resistance between the brush and the commutator is very large, which causes the overall resistance of the motor to be large and easy to generate heat. The permanent magnet is a thermal element. If the temperature is too high, magnet will demagnetize, the performance of the motor is reduced, and the life of the brushed motor is affected.


4. Low efficiency and low output power


The heating problem of the brushed motor is because the current is done on the internal resistance of the motor, so the electrical energy is converted to heat energy to a large extent, resulting in the low output power and low efficiency of the brushed motor.



Brushless motor advantages


1. No brush, low interference


The brushless motor removes the electric brush and eliminates the electric spark generated when the brush motor is running, reducing the electric spark's interference to the remote control radio equipment.


2. Low noise and smooth operation


The brushless motor has no brush, the friction is greatly reduced during operation, the operation is smooth, and the noise is much lower.


3. Long lifespan, low maintenance cost


Without brushes, the wear of the brushless motor is mainly on the bearing. The brushless motor is a maintenance-free motor and only needs some dust removal maintenance. However, brushed motors are irreplaceable for their excellent low-speed torque performance and large torque. From the point of view of the ease of use of brushless motors, with the decline in the cost of brushless controllers and the development of brushless technology at home and abroad, brushless power systems are developing at a high speed.


4. Application of brushless motor and brush motor


Brushless motors are used in equipment with relatively high control requirements and high speeds, such as aircraft models, precision instruments, etc., which have strict control of the motor speed and high speeds. The lifespan of brushless motors is tens of thousands of hours, but the service life of brushless motors is also very different due to different bearings. Brushless motors controlled by inverter technology will save more energy than series motors. The most typical ones are inverter air conditioners and refrigerators. In addition, BLDC motors are also used in service robots and drones.



Brushed motors are used in medical analytical instruments, infusion pumps and electronic integrated surface mount equipment.



Why choose motor production line?


The increasing labor costs and the unwillingness of young people to work in factories have led to the continuous increase of labor costs for companies, and the problem of difficulty in recruiting workers has always existed, especially for assembly skilled workers. Insufficient labor will affect the production schedule of the order and even delay delivery. Investing in motor manufacturing equipment can not only improve production efficiency, but also reduce labor and management costs, and improve product quality qualification rate. Optimize the company structure to realize smart factories and digital production. In addition, the addition of automation equipment can effectively improve the overall strength and production capacity of the company, thereby gaining more large-scale orders and increasing the company's profits. If the added value of the motor produced is high and the demand is large, the cost of the input equipment can usually be recovered in one and a half years.

Related News