With the development of electronic technology, computer technology, rare earth permanent magnet technology, sensors, motor control theory and lithium battery in electric tools, power tools are increasingly demanding technology.
In the design of power tools and consumer purchases, “brushless” and “brushed” are often mentioned, and they mainly refer to brushless motors and brushed motors. Then what make the differences?
1. When the motor with brush is working, the coil and commutator rotate, the magnetic steel and carbon brush do not rotate, and the alternating change of the coil current direction is completed by the commutator and brush that rotate with the motor.
2. The brushed motor is a traditional product with relatively stable performance. The brushless motor is an upgraded product, and its life performance is better than that of the brushed motor. However, its control circuit is relatively complicated, and the aging screening requirements for components are relatively strict.
3. The brushless DC motor is composed of a motor body and a driver, and is a typical mechatronic product. Since the brushless DC motor operates in a self-control mode, it does not add a starting winding to the rotor like a synchronous motor with heavy load under variable frequency speed regulation. At the same time, it does not produce oscillation when the load changes suddenly.
At present, it is generally believed that brushless motor power tools have the following advantages:
(1). Brushless motor with long service life and maintenance-free
The service life of the tool mainly depends on the wear and tear of the gearbox, bearings, and electronic circuits.
Taking FIXMAN brushless power tool as an example. If it is used normally, the service life is about 2 times longer than that of brushed products
(2). Brushless motor saves power
In general, brushless tools save 30% power than the same brushed tools, which not only reflects excellent performance, but also seems to be more eco-friendly.
One working time increases by 30%, and three times by 90%, which means that three to four times of working can save one charge. By this way, the battery life is extended to a certain extent.
(3). Adapt to a wider fields and situations
Electric tools with a built-in brushless DC motor do not generate sparks during operation. If the drive circuit is designed with dust-proof and moisture-proof protection, there is basically no need for maintenance.
That is, for the situations where sparks are prohibited, brushless electric tools may be more practical.
The brushed motor has its advantages, that is, low cost and easy control. The cost of brushless motors is generally much higher, and the control requires more professional knowledge.
Controllers for brushless motors are expensive. It's fine if it's not damaged, but once it's broken, it's likely to have to be replaced entirely. On the other hand, tools with carbon brushes usually only need to replace the carbon brushes(for few dollars). As long as it is not a motor problem, it is a small problem.