The parameters of the model of the brushless motor, in addition to the physical dimension (Diameter, length, diameter of axle, etc. ), weight, voltage range, no-load current, maximum current and other parameters, also an important index & ndash; KV value, this value is unique to the brushless motor of a performance parameter, is brushless motor performance characteristics of an important data.
brushless motors KV value is defined as: RPM/V, means the input voltage increase 1 KV, brushless motor speed value of the idle speed increase. Always this definition, we can know, brushless motor voltage input and motor idling speed is a strict linear proportional relationship. Brushless motor not only explain the meaning of a strict linear proportional relationship motor speed and voltage, and also for the performance of the motor has an open sex said. Brushless motor used friends have this kind of feeling, mostly with level (Outside diameter)Outside the brushless motor, the rotor and the inner rotor electricity compare, model aircraft brushless electric chance find torsion bigger, exterior rotor motor to & other; Hard & throughout; Some inner rotor motor torque slightly smaller, & other; Soft & throughout; Some, a look at the motor parameter, exterior rotor motor KV value of more than 800, more than 1000 to more than 2000 inner rotor motor. Look at the speed, the inner rotor motor speed significantly higher than the external rotor motor.
in fact, these features are related with the KV value, as defined by the KV value to explain, brushless motor idling speed, is KV value multiplied by the input voltage, which could explain why the inner rotor motor speed higher than that of exterior rotor brushless motors. For torque characteristics, KV value embodies the motor torque performance on certain significance, for external rotor motor, the no-load speed of the motor is ordinary, but add load (Such as propeller)After its landing speed to the no-load speed of 60%70%, but with the same level to test the inner rotor motor, the speed can only load to the no-load speed of 30%40%, which obviously reflects the torque characteristics of the difference between these two kinds of motor, the inner rotor motor load capacity is relatively low, in order to satisfy the torsion power, inner rotor motor required to slow down and increase by electric current, in the case of constant voltage, the motor output power is increased, the inner rotor motor torque characteristic is reflected on the specific application, before a lot of light foam fixed wing aircraft, originally used in the rotor brushless motor, but for the sake of torque characteristics, the plane is not directly connected to the motor of the propeller,Not a direct-drive), but added a reduction gear group, in order to improve the inner rotor motor torque performance. With the series with the dimensions of brushless motor, KV value can also be the difference between the motor characteristics, such as B3674 inner rotor motor, a KV value is 1860, including a KV value is 2075, the first motor torque is larger, the peak current work is relatively small; A second motor technology, but the torsion properties is less than the first motor, peak current will be larger. The significance of brushless motors KV, must let you benefit a lot. Some basic knowledge of brushless motor model with brushless low KV value of 12000, high - 56000, he said the higher voltage per 1 v, speed increase value, for brushless, this value is a constant. For the same size of brushless: winding circle number, low KV value, maximum output current is small, but large torque; Winding circle number less, high KV value, maximum output current is big, but small torque; Single from KV value, can not evaluate motor is good or bad, because different KV value have different applicable occasions: low voltage,7. 4v）, low KV value, due to the low speed, match with small reduction ratio and large propeller, ascension by large load current, the output is high power; KV value high, due to the high speed, match with large reduction ratio and the smaller the propeller, under the condition of meet the power output, to reduce the load, and avoid excessive current; High voltage environment (11. 1 v), low KV value, dc brushless motor factory, dongguan in this voltage can achieve high speed, the torque is good also, ideal. Need to match and large reduction ratio and the smaller the propeller, under the condition of meet the power output, to reduce the load, and avoid excessive current; KV value high speed is too high in this environment, in order to avoid too much electricity, try to reduce the load. With its high speed, with the word of Yu Han fan engine is appropriate.
