What are brushless motors and their characteristics
What is a brushless motor?
Brushless DC motor is a typical mechatronics product, which is composed of motor body and driver. Brushless motor refers to the motor without brush and commutator (or collector ring), also known as commutator free motor. As early as the birth of the motor in the last century, the practical motor produced is a brushless form, that is, the AC squirrel cage asynchronous motor, which has been widely used. However, asynchronous motors have many insurmountable defects, so that the development of motor technology is slow. The transistor was born in the middle of this century, so the brushless DC motor using transistor commutator circuit instead of brush and commutator came into being. This new brushless motor is called electronically commutated DC motor, which overcomes the shortcomings of the first generation of brushless motors.
Brushless motor features
1, can replace DC motor speed regulation, inverter + frequency conversion motor speed regulation, asynchronous motor + reducer speed regulation;
2, with the advantages of traditional DC motor, but also cancel the carbon brush, slip ring structure;
3, brake, double steering function;
4, small size, light weight, large output;
5, excellent torque characteristics, medium and low speed torque performance is good, starting torque is large, starting current is small;
6, stepless speed regulation, wide speed range, strong overload capacity;
7, soft start and soft stop, good braking characteristics, can save the original mechanical braking or electromagnetic braking device;
8, high efficiency, the motor itself has no excitation loss and carbon brush loss, eliminating multistage deceleration loss, and the comprehensive power saving rate can reach 20% to 60%.
9, high reliability, good stability, strong adaptability, simple maintenance and maintenance;
10, bumpy vibration resistance, low noise, small vibration, smooth operation, long life;
11, no spark, especially suitable for explosive places, explosion-proof type;
12, according to the need to choose trapezoidal wave magnetic field motor and sine wave magnetic field motor.
Advantages of brushless motors
Different from the brushed DC motor, the brushless DC motor does not use a mechanical brush device, the square wave automatic permanent magnet synchronous motor, the Hall sensor replaces the carbon brush commutator, the NdFeb as the rotor permanent magnet material, the performance compared with the general traditional DC motor has great advantages, is today's most ideal speed control motor.
High efficiency, low energy consumption, low noise, long life, high reliability, servo control, stepless frequency control, relatively low cost and easy to use.
The stator winding of the brushless DC motor is mostly made of three-phase symmetrical star connection, which is very similar to the three-phase asynchronous motor. A magnetized permanent magnet is attached to the rotor of the motor, and a position sensor is installed in the motor to detect the polarity of the rotor. The driver is composed of power electronic devices and integrated circuits, etc. Its function is: to accept the start, stop and brake signals of the motor to control the start, stop and brake of the motor; The position sensor signal and positive and negative turning signal are accepted to control the on-off of each power tube of the inverter bridge to generate continuous torque; Receive speed instructions and speed feedback signals to control and adjust the speed; Provide protection and display and more.
Dc brushless motors are widely used in household appliances, auto parts, power tools, office automation, industrial and commercial equipment, medical equipment, personal care, robotics and many other industries.