Commonly used electric self-confidence car motor for permanent magnet DC motor, to reach 10 N. M above the running torque, the motor power should be in the range of 100 ~ 200w, the working voltage of 24V or 36V, the motor requires starting torque, high efficiency, light weight, and a certain overload capacity. In addition to the common internal rotor motor driven by chain drive or direct friction outside the wheel, and the outer rotor DC motor can be installed in the middle of the wheel, through the planetary gear reduction mechanism directly drive the hub, this motor is also known as the hub motor. It has a short drive chain, high efficiency, compact structure and so on. DC motor excitation mode, in addition to the permanent magnetic field, you can also use the string excited excitation. String drive DC motor operating characteristics of soft, good speed performance, starting torque, although it is slightly more expensive than the permanent magnet motor, or made some applications. This type of motor price is very cheap, the user's own production is very cost-effective conversion. This type of drive is recognized as better. And whether the use of brush motor or brushless motor, is currently controversial.
Brush motor output speed of 3000 r / min or more, the reducer and beyond the clutch and the shell together to form a motor hub assembly, the speed of 170-180 r / min, adapted to the bike to 20km / h speed. The structure of the high reliability, low cost, riding more comfortable, but there are the following shortcomings: the traditional brush and commutator mechanical wear and noise, sparks, the system of advanced and grade is not high enough.
Brushless electric wheels for electric bicycles are actually composed of two parts. First, the direct external rotorless brushless motor system, the second is to achieve electronic commutation of the special control system, brushless motor based on modern IC technology and power electric bike kit device development and gradually mature. It is not difficult to master the producers who have experience in electronic technology.