The history of 48V brushless DC motor can be traced back to the early days of motor development. As early as the 19th century, the first motor used in industry was a brushless form, namely the AC squirrel cage asynchronous motor. This motor quickly gained widespread use due to its simple structure and strong durability. However, with the development of motor technology, traditional brushed DC motors have occupied a place in some applications due to their large starting torque and good speed regulation performance. However, the disadvantages of brushed motors, such as easy wear of carbon brushes and commutators, high noise, and low efficiency, have prompted people to seek improvements.
With the invention of transistors in the mid-20th century, brushless DC motors based on transistor commutation circuits came into being. Compared with traditional brushed motors, 48V brushless DC motors overcome problems such as carbon brush wear and commutator failure, and have higher efficiency, lower maintenance requirements, and longer service life. Therefore, 48V brushless DC motors have been increasingly widely used in occasions where frequent starting and precise speed regulation are required, such as electric vehicles, industrial automation equipment, and household appliances.
Differences between brushless DC motor and brushed DC motor
1. Differences in working principles
48V brushless DC motor:
The rotor of a brushless motor is composed of permanent magnets, and the stator is formed by coil windings. Brushless motors rely on position sensors such as Hall sensors to detect the polarity of the rotor, and the driver controls the switching of current by controlling the electronic commutator (usually a three-phase bridge conversion circuit) to drive the rotor to rotate. The key is to achieve the start, stop, brake, speed regulation and other control of the motor through the driver. Brushless motors do not produce physical friction in the commutation process, so they can achieve efficient and smooth operation, produce continuous torque output, and provide protection functions such as overload and overheating to ensure the long-term stable operation of the motor.
Brushed DC motor:
Brushed motors use carbon brushes to contact the commutator. The commutator is responsible for changing the direction of the current in the armature winding, so that the rotor can rotate continuously in the static magnetic field of the stator. As the rotor rotates, the carbon brushes slide on the commutator, continuously switching the current to drive the rotation of the rotor. Due to the presence of mechanical contact parts, carbon brushes and commutators are prone to wear in long-term use, resulting in high maintenance costs, and sparks and noise will be generated during operation. These problems are particularly evident under high speed and heavy load conditions.
2. Structural differences
48V brushless DC motor:
The basic structure of a brushless motor consists of a motor body and a driver. The stator winding of the motor is usually a three-phase symmetrical star connection, and the rotor is a permanent magnet. As an important part of the control system, the driver is composed of power electronics and integrated circuits. Brushless motors rely on electronic commutation to replace traditional mechanical commutation, so carbon brushes and commutators are not required, the structure is simpler, and mechanical losses are reduced. Due to the high precision and flexibility of electronic commutation, the performance adjustment of the motor is also more precise and stable.
Brushed DC motor:
The basic structure of a brushless motor consists of a stator, a rotor, carbon brushes and a commutator. The stator is generally composed of permanent magnets or electromagnets, the rotor is an armature winding, and the carbon brushes and the commutator complete the conversion of the current direction through physical contact to ensure that the motor continues to rotate. Due to the existence of mechanical contact, the wear of carbon brushes is an obvious weakness of brush motors. In addition, the commutator may cause electrical noise and electromagnetic interference when the motor runs at high speed. Although the structure of brush motors is relatively simple and the control circuit is relatively simple, their life and reliability are far inferior to brushless motors.
3. Performance difference
48V brushless DC motor:
The efficiency of brushless motors is generally 20%-30% higher than that of brush motors, especially in situations where precise speed and position control are required. Due to the lack of carbon brush wear, the service life of the motor is significantly extended and the maintenance cost is low. Brushless motors can still maintain stable operation at high speeds and high loads, and have good overload capacity and instantaneous starting performance.
Brushed DC motor:
Although brushed motors have large starting torque and simple control, their efficiency is low, especially in long-term operation, as the carbon brushes wear, the efficiency further decreases. Brushed motors are suitable for applications with lower requirements, but in applications with high-frequency starting and strict speed regulation requirements, performance bottlenecks are prone to occur and the life is relatively short.
4. Differences in application scenarios
48V brushless DC motor:
Brushless motors are widely used in applications that require high precision, long life, and low noise, such as electric vehicles, drones, industrial automation equipment, air conditioning compressors, etc. Due to its design without mechanical commutation, it is particularly suitable for applications that require high reliability and frequent starting and speed regulation.
Brushed DC motor:
Brushed motors are commonly found in areas with low costs and low usage requirements, such as small household appliances, toys, fans, etc. Due to its large starting torque, some areas still retain the application of brushed motors, especially those that do not require long-term stable operation.
Conclusion
Overall, 48V brushless DC motors are gradually replacing traditional brushed motors with their superior efficiency, long life, low maintenance, and high performance, especially in the fields of precision control and industrial automation.
