1. DC brushless motor DC motor will produce constant torque performance under rated load. Since the armature magnetic field and the rotor magnetic field are constantly maintained at 90 degrees, the carbon brushes and commutator must be passed through. It is easy to cause electrical sparks to damage the components. Since AC motors do not have carbon brushes and commutators, they do not need corresponding maintenance, but the performance is more complicated than the performance control effects of DC motors.The switching frequency of semiconductors is faster, so it can significantly improve the performance of the drive motor, and the speed of the microprocessor is getting faster and faster, which ensures the control of the AC motor and realizes the appropriate control in the two-week rectangular coordinate system. In addition, due to many micro The processor can have the necessary China Precision Cycloidal Gearbox Manufacturers for controlling the motor, so the volume is getting smaller and smaller. The position sensor plays a role in determining the position of the rotor magnetic pole in the DC brushless motor, and provides the correct commutation information for the logic switch circuit, that is, the position signal of the rotor magnetic steel pole is converted into an electrical signal, and then the commutation of the stator winding is controlled. There are many types of position sensors, and each has its own characteristics. Common position sensors in DC brushless motors include the following types: electromagnetic position sensors, photoelectric position sensors, and magnetic-sensitive position proximity sensors. In the DC brushless motor, the electromagnetic position sensor is the open transformer. The open transformer used for three-phase DC brushless motors is composed of a stator and a tracking rotor. The stator generally has six poles, with an interval of 60 degrees between them. Three poles are wound with a primary winding and connected in series with each other to connect to a high-frequency power supply. The other three poles are wound with secondary windings WA, WB, WC. They are separated by 120 degrees. The tracking rotor is a cylinder made of non-magnetic material, and a 120-degree sector-shaped magnetic material is embedded on it. Connect it to the shaft of the motor during installation, and its position corresponds to a certain magnetic pole. The high-frequency magnetic flux generated by the primary winding is coupled to the secondary winding by tracking the material on the rotor, so an induced voltage is generated on the secondary winding, and the other two-phase secondary windings are connected to the primary winding due to no coupling loop. , The induced voltage is basically zero. As the rotor of the motor rotates, the sector plate also rotates so that it leaves the currently coupled primary winding and approaches the next primary winding. In this way, as the motor rotor moves, voltages are respectively induced on the secondary windings of the open transformer. The angle of the sector-shaped magnetic conductive sheet is generally slightly larger than 120 degrees in electrical angle, and about 130 degrees in electrical angle is often used. In the three-phase full-control circuit, for the needs of the commutation decoder, the angle of the sector-shaped magnetic conductive sheet is 180 degrees in electrical angle. At the same time, the number of sector-shaped magnetic plates should be equal to the number of pole pairs of the DC brushless motor.2. Classification of brushless DC motors Generally speaking, DC motors have the same working principle and application characteristics, but there is a big gap in the composition of the thing itself. In addition to the motor, it will also increase the commutation circuit and the phantom of the motor itself. The circuit is closely combined to ensure that many low-power motors are integrated with the commutation circuit. This ensures that the appearance of the DC brushless motor and the DC motor are completely consistent. The DC brushless motor consists of electromechanical energy and electromechanical energy. The armature and permanent excitation are composed of two parts, including sensors. Through the DC brushless special code of the motor itself, it can effectively strengthen the performance indicators, vibration operation, and service life of the DC motor, while reducing manufacturing costs and production costs. For permanent magnet magnetic field, the use of DC brushless motors can be more flexible design, which can effectively meet the market demand. On the other hand, it can also save materials and make it easier to manufacture. The development of permanent magnetic fields is closely related to the development of permanent magnetic materials. Through continuous innovation of permanent magnetic materials, it can ensure that the DC brushless motor can be upgraded. It is not only more efficient, but also smaller in size, and can also have good energy-saving effects.3. The application of brushless DC motor also uses the position signal to ensure the effect of electronic commutation. In the early days, the electromechanical position sensor to obtain the TV signal has been gradually replaced by the electronic position sensor or other methods. The most commonly used method is the armature winding. In order to ensure the validity of the motor speed, an advanced method of obtaining position signals. The simplest speed sensor device is the combination of speed measurement and information transmission with electronic circuits. From the current point of view, the commutation circuit of the DC brushless motor is composed of two parts: drive and control. Especially for low-power circuits, the two can be integrated to form a dedicated integrated circuit. Because the motor with larger power can design the drive circuit and the control circuit separately, it is ensured that the output power of the drive circuit and the armature winding of the drive motor are under unified control. The drive circuit, through the linear amplification state. The pulse width modulation switch is formed to further complete the transistor separation, and the circuit is converted into a modular integrated circuit. The power of the modular integrated circuit is used to ensure the efficiency of the frost ice stadium. The price of the supervision isolation gate field effect bipolar transistor is very expensive. But it also has a higher cost performance, because the safety and reliability of the isolation gate field effect bipolar transistor are better. The control circuit can be protected by controlling the rotation speed of the motor. Moreover, these signals can be converted into analog signals in time, which is more convenient for circuit control. From the current stage. In the process of converting the parameters of the motor into digital integrated circuits, the requirements for control occasions are not high, and the control circuit converted into an application specific integrated circuit has simpler performance characteristics. As current. The control circuit composed of the digital signal processor adapts to the future development direction, so in the digital signal processor, the AC synchronous servo motor has an important application. From the current point of view, the application range of brushless DC motors is very wide, such as automotive tool industrial control, automation, and aerospace and other fields can see brushless DC motors. Specifically, brushless DC motors can be used in the above three aspects. First, for products such as fan, pump, blower, etc., because they do not require high speed accuracy, but have relatively high speed requirements, they can pass. The application of brushed DC motors can not only control the cost, but also ensure the speed effect. In addition, for example, dryers and compressors can be changed within a certain range, which requires higher performance and dynamic response performance of the motor. .
