来源：http://www.jnmcd.com 发布时间：2019-05-29 浏览：次
The cost of brushless motor is mainly in the drive board, so the price of single-phase is much lower than that of three-phase. External rotor brushless motor is cheap, mainly because it can be driven by single-phase. The advantage of single phase is low price, but the disadvantage is low torque and low power. To achieve the same three-phase torsion of single-phase external rotor, the size of the motor should be large. In some places where the requirement for torsion is not high, such as driving the fan blade, it is enough to use the external rotor.
Inner rotor brushless motor has high price, fast speed and high torque. For example, the brushless motor of the vehicle vacuum cleaner uses the inner rotor, and its speed is as high as 30,000 revolutions! The inner rotor is usually three-phase, but its output is low. The winding mode of the inner rotor is more complex than that of the outer rotor. The output of the inner rotor is much lower than that of the outer rotor. Large-scale consumption tests the production capacity of the factory. The price of inner rotor brushless motor is usually tens of yuan a set, the price of high power is higher, ordinary high-end places can use.
Besides, brushless speed reduction motor. At present, brushless motors are mainly low-power, and high-power brushless motors over 1 kilowatt cost a lot. Therefore, under the condition of large torsion, the ordinary brushless motor is usually used with a reducer, at this time, the reducer becomes a short plate. Good performance gearboxes, such as planetary gearboxes, cost a lot of money, and their life can reach 8,000 hours, while ordinary gearboxes cost less, but their life is only 2,000 hours. The idea that the life of the brushless speed reducer is tens of thousands of hours is to neglect the short plate of the gear reducer. Carbon brush motor with reducer usually costs only a dozen yuan, but the service life is only tens of hours to hundreds of hours. Brushless motor with planetary gear reducer, the price is more than a hundred yuan a set, the use of life has improved more than ten times, but the cost has also increased ten times! A planetary gearbox costs more than 60 yuan. Using brushless motor with ordinary reducer, the price is obviously much lower, but I feel a little wasteful of motor performance.
As for the request speed is very low and the rotation can be accurately controlled, it is not advisable to use ordinary brushless motor. Stepper motor can be selected at this time. Stepping motor is a kind of brushless motor, and also needs to be driven. Miniature stepper motors are inexpensive, but also have low torsion. Of course, the angle can be accurately controlled. Because of the low torsion, miniature stepper motors are usually used with reducer. High-power stepper motors are expensive.