来源：http://www.jnmcd.com 发布时间：2019-07-24 浏览：次
Compared with brushless motors, brushless motors are well known for their naming. Generally, they are composed of four numbers, such as 2040 brushless motors. This figure only represents the size of the motor. 2040 represents a motor with a diameter of 20 mm and a length of 40 mm. Similarly, the 3650 brushless motor is 36mm in diameter and 50mm in length.
In fact, 370 brushless motor is the same size as 2530 brushless motor, 540 motor is the same size as 3650 brushless motor.
Characteristics of Brushless Motor
1. There is no carbon brush. In theory, the rotor does not need to be connected with the outside conductor.
2. In the process of operation, the speed of the brushless motor is determined by the frequency of alternating current, so the higher the frequency, the faster the brushless motor can rotate.
3. The speed of the brushless motor is set strictly according to the KV value. 1000KV means that the speed of each Ford motor is increased by 1000 revolutions. So when the voltage is 5V, the speed of 1000kV brushless motor is 5000rpm.
4. In the process of operation, the torque of the motor with the same speed is determined by the current intensity output by electric regulation. The greater the current, the greater the torque. (Ideally, our "smart" brushless tuning would "monitor" from time to time whether our motors need more torque, but also ensure that the torque is not excessive, so as not to waste expression)
Brushless Motor with Outer and Inner Rotors
The working principle diagram of the brushless motor above shows the inner rotor brushless motor. The magnet is inside. On the contrary, the outer rotor brushless motor has its magnet "wrapped" outside. The A, B and C electrodes are inside. Such a design can make the motor more torsional, but the speed is not up. In the model, the KV value of the ordinary outer rotor brushless motor is less than 2000, while the inner rotor brushless motor can reach 8000-9000 kv. For this reason, brushless motor with outer rotor is common in common aircraft, while brushless motor with inner rotor is commonly used in model vehicle and model ship.
Feeling Brushless and Senseless Brushless
To clarify this problem, first of all, we need to understand what sensation is. Sensation in brushless sensation refers to "Hall sensor". So what is "Hall"? Hall refers to the Hall effect, which was discovered by American physicist A. H. Hall (1855 - 1938) in 1879 when he studied the conductive mechanism of metals. When the current passes through the conductor perpendicular to the external magnetic field, there will be a potential difference between the two ends perpendicular to the magnetic field and the current direction. This phenomenon is Hall effect. This potential difference is also called Hall potential difference.
So why do we feel this thing? To clarify this problem, we must start with a defect of senseless brushless. It was just said that the speed of brushless motor is determined by AC frequency, so the electric regulation should try to find out the speed of the motor and the current state of the motor. In fact, it's easy for a motor that used to run normally, but it's more difficult for a motor that just started or operated slowly (it's difficult to measure the speed of the motor more accurately), so the linearity of the brushless induction timing is not good at low speed, so it may tremble, and the starting torque is also difficult. It is better than brush motor of the same grade.
However, it is found that no matter what operating state of the brushless motor, its Hall effect is obvious, so it is easy to know the operating state of the high-speed or low-speed motor through Hall effect adjustment, thus dealing with the shortcomings of the induction brushless motor! But at present, Hall sensor is not a low price, so the price of sensorless brushless motor and electric regulation will be much higher than that of sensorless brushless.