The Difference Between Dc Brushless Motors And Brushed Motors In Micro-Pump Applications
In the DC motor, brush motor is the earliest contact with a class of motors, secondary school physics classroom to introduce the motor is also to show it as a model. The DC brushless motor is a new type of motor, which has been gradually applied to daily life in recent years. But in fact, as early as 1917, the basic idea of brushless DC motor has been born, because the brush motor brushes are easy to be worn out is a fatal shortcoming, which affects the brush motor in the field of the overall application, people need a can not need to be maintained on the long-term use of the motor to replace it. It wasn't until 1955, when D. Harrison and others in the United States first applied for a patent to replace the mechanical brushes of a brushed DC motor with transistorised commutation lines, that the birth of the modern brushless motor was officially marked. So what is the difference between them?
Brushed Motor Principle
The basic structure of a brushed motor is: stator (pole), rotor (coil), mechanical brushes (carbon brushes) and commutator. The basic principle of the motor is to obtain the rotating torque through the magnetic field commutation rotation, so as to output kinetic energy. The mechanical brushes and commutator of brush motor play the role of conductivity and phase change in the rotation, so the brushes and commutator should be in constant contact with the friction, and need to replace the carbon brushes on a regular basis.
Brushless Motor Principle
The basic structure of a brushless motor: stator (coil), rotor (pole), position sensor (Hall sensor) and controller. The basic principle of the motor is to change the magnetic field to obtain the rotating torque, so as to output kinetic energy. The position sensor and controller act as electronic commutators. Brushless motor in operation, the coil does not move, the magnetic pole rotates, through the Hall element, sensing the position of the magnet poles, according to this induction, the appropriate time to switch the direction of the coil current, to ensure that the production of the correct direction of the magnetic force to drive the motor, eliminating the shortcomings of the mechanical commutation of the brush motor.
Performance Difference Analysis
1, Brush motor structure is simple, low cost, easy to fail is the carbon brush wear. Brushless motor because of the removal of brushes, the use of electronic commutation, the cost is more expensive, but from a mechanical point of view, brushless motor is almost maintenance-free.
2, Brushless compared to brush motors is another advantage of low interference, no brush motor operation generated by sparks, digital signal control, greatly reducing the interference with other equipment.
3,Noise, smooth running brushless motor without brushes, running friction is greatly reduced, smooth running, noise will be much lower.
4, Speed regulation, brush and brushless motor control is essentially by regulating the voltage, just brushless DC using electronic commutation, the use of silicon controlled circuit control, through digital control to achieve. Brushed motor is to adjust the motor supply voltage high and low, change the electrode generated magnetic field strength, to change the speed of the purpose. While the brushless motor speed regulation, the motor supply voltage is unchanged, change the control signal of the ESC, and then change the switching time of the MOS tube through the internal controller to achieve the purpose of speed change.