Brushless DC motor, the use of electronic Hall elements to imitate the carbon brush phase change, theoretically brushless DC motor can solve the problem of easy wear and tear of the carbon brush, bringing convenience and reliability to the maintenance, and the noise is reduced a lot.
The essence of the brushless DC motor is an AC motor. It needs to turn on the pulse voltage of each phase coil in turn, so it needs a stable DC power supply on the bus to work. If there is no DC power supply, it needs to rectify the AC power to DC before it can be used. And the control coil is turned on. A large number of switch tubes are required, and the collection and processing of Hall signals require related circuits and control chips. Because the control part of the brushless motor is much more complicated than that of the brushed motor, the cost will be much more expensive, and the Hall needs to be more expensive. Wiring, if the line is broken, will also affect the use.
Because the brushless DC motor is a mechatronic system, the volume will be larger than the brush motor, and because of the torque and high-speed performance and brush motor differences, so currently in the washing machine, exhaust fans, hair dryers, vacuum cleaners, and other household appliances. Brush motors are still used on a large scale. Technology is progressing, although the current brush motor, in small devices such as electric work still large-scale use of brush motor, but do not rule out the possibility of future technological advances, brushless DC motor will still have to replace the brushless motor.
Early electric vehicles are also used on the brush motor, the current mainstream has become brushless motors. The industrial system is also - the beginning of the large-scale use of brush DC speed control system, but has now transitioned to asynchronous motor + inverter as the main speed control device, also brushless, from the experience of these industries, brush motor carbon brush congenital deficiency, is the core of the fundamental eliminated. In the future, the DC brushless motor industry is large enough to be able to reduce the price down. And high-power electronic components technology has been a breakthrough, the volume to do very small, and the capacity to do every day, brushless motor energy I volume ratio increased, also does not exclude small appliances and power tools and other occasions large-scale use of a brushless motor.
In addition, no Hall start is also an important detail, the use of Hall in power tools to switch the phase of brushless motors, an additional detection link, if the abolition of Hall to start, instant start torque and speed will fluctuate more. If the starting algorithm is mature, (enough to solve this problem of Hall-less starting, perhaps power tools and motorcycle starting motors, may be replaced by brushless DC motors.
Brushless DC motor technology power tools, subvert the traditional power tools mechanical commutation structure, completely solving the fatal problem of workers can not replace the carbon brushes in a timely manner is very likely to cause motor burn and the size of the machine is bulky and inconvenient to operate, the motor continuous work temperature problem, improve product life and efficiency, and greatly reduce the weight and volume of the product.
Brushless DC motor + drive control device + clutch device can be made into an electric wrench; with a rechargeable battery, it can be made into a portable electric wrench. It is mainly used in the field of removing automobile tires and so on.
Electric grinding machine
A Brushless DC motor is used in an electric grinder, it does not need to change the brush maintenance work, and the speed can be controlled according to the situation of the grinding workpiece, the noise is greatly reduced compared with the original brush motor, and because the voltage is DC, the voltage is reduced, the safety is greatly improved.
Brushless DC motor can change the speed to ensure that the cutting line speed is consistent after the cutting blade wears out to ensure the quality of cutting, brushless DC motor cutting force is large, but once encountered in the case of blockage, then immediately stop, to ensure the safety of equipment and life.