Brushless motors and brushed motors are two different types of power devices. Their differences lie in structural design, which also has a direct impact on performance, lifespan, and application scenarios.
Structural Design
Brushed Motors: They contain brushes and a commutator inside. Power is supplied through the physical contact between the brushes and the rotor, and the commutator changes the direction of the current to maintain the rotation of the rotor.
Brushless Motors: The brushes and commutator are eliminated. Permanent magnets are installed on the rotor, and the external controller is used to adjust the direction of the current.
Analogy for Understanding: A brushed motor is like a manual transmission car that requires manual gear shifting; a brushless motor is like an automatic transmission car that is intelligently controlled by a computer.
Working Principle
Brushed Motors: The current is transmitted to the rotor coil through the brushes, generating a magnetic field to push the rotor to rotate. However, this will generate friction, noise, and electromagnetic interference.
Brushless Motors: The controller adjusts the direction of the current according to the position of the rotor, forming a rotating magnetic field to drive the rotor to rotate. There is no need for physical contact, and the operation is quiet.
Performance Comparison
Efficiency: The efficiency of a brushed motor is 60%-75%, while that of a brushless motor can reach 85%-95%.
Lifespan: The lifespan of a brushed motor is limited by the wear of the brushes, while a brushless motor can reach tens of thousands of hours due to the absence of wear components.
Speed and Torque: The torque of a brushed motor drops relatively quickly, while a brushless motor can output stable torque at different speeds.
Noise and Maintenance: Brushed motors are noisy and require frequent maintenance, while brushless motors are almost noiseless and maintenance-free.
Application Scenarios
Brushed motors are suitable for low-cost scenarios, such as toys, inexpensive tools, etc.; brushless motors are widely used in high-performance fields, such as consumer electronics, industry, transportation, and special environments.
Cost and Trends
The initial cost of brushless motors is relatively high, but they can save energy consumption and maintenance costs in the long run, and have a better development prospect in the future. On the other hand, brushed motors are gradually phasing out of the market.
There are obvious differences between brushless motors and brushed motors, which are like a microcosm of the evolution of electric drive technology. Brushed motors have a simple structure. Although they were once very popular, they have low efficiency, a short lifespan, and have an adverse impact on the environment, and cannot meet the modern industry’s requirements for high efficiency, reliability, and intelligence. Brushless motors combine electronic commutation technology and permanent magnet materials, overcoming the performance limitations of traditional motors, and have become the core driving force in the fields of new energy, automation, and precision manufacturing.