What is a DC brushless motor? What are the characteristics of brushless motors.
DC brushless motor is composed of an electric motor and a driver, and is a typical electromechanical integrated product. Brushless motor refers to a motor without brushes and commutators, also known as a commutatorless motor. Its performance is comparable to other military grade reducer products, but it has the price of industrial grade products. It is mainly used for the slewing mechanism of tower cranes and can also be used as a supporting component in industries such as lifting, transportation, construction, and excavation. Often applied in industrial production such as intelligent systems, aerospace, aviation, household equipment, metallurgy, printing equipment, automated production lines, CNC machine tools, etc.
DC brushless motor is a type of synchronous motor, and the stator winding of the motor is mostly made into a three-phase symmetrical star connection, which is very similar to three-phase asynchronous motors. The rotor of the motor is glued with magnetized permanent magnets. In order to detect the polarity of the motor rotor, a position sensor is installed inside the motor. The driver is composed of power electronic devices and integrated circuits.
1、 The basic characteristic of a brushless DC motor is that it does not require the use of mechanical shocks such as brushes and rectifiers, which are commonly considered drawbacks of DC motors. DC motors use brushes and rectifiers to rotate, so regular maintenance is required. Brushless motors use signals detected by Hall ICs to rotate using the ON/OFF of transistors in the drive circuit, so no maintenance is required.
2、 Brushless deceleration motors can achieve stable speed control by continuously comparing the set speed with the speed feedback signal from the motor to adjust the voltage applied to the motor; Therefore, even if the load condition changes, it can still be instantly adjusted from low speed to the set speed and run at this stable speed. Three phase induction motors controlled by frequency converters do not have feedback control, so when the load increases, the speed will decrease significantly. For applications that require high speed stability, it is recommended to use brushless motors.
3、 The use of DC brushless motors helps to save energy. The rotor of brushless motors uses permanent magnets, which can reduce secondary losses of the rotor. Therefore, compared with three-phase induction motors that use variable frequency control, the power consumption is reduced by about 23%. Helps to save energy for the device.
4、 The rotor of a brushless motor uses permanent magnets, thus achieving thin and high power. For example, compared with a 90 type three-phase induction motor, the total length is shortened by more than 75mm, and the output power reaches 1.3 times. If a brushless motor is used, it helps to achieve miniaturization of the device.
5、 Due to the installation of overcurrent, phase loss, undervoltage and other protection functions, brushless DC motors are equipped with protection functions, which help to protect the safety of the equipment system and ensure the safety of the equipment system during operation.
6、 The speed control range of DC brushless motors is wide, and the speed control range of brushless motors is wider than that of AC speed regulating motors and frequency converters. Unlike AC speed regulating motors, which have torque limitations at low speeds, brushless motors are suitable for applications that require a certain amount of torque from low to high speeds.
