The so-called economical E-bike middle motor, its main function is to convert electrical energy into mechanical motion, thereby driving the wheel forward. At present, the commonly used motor is a permanent magnet DC motor. To achieve an operating torque of 10 N.m or more, the power of the motor should be in the range of 100 to 200 W, and the working voltage is 24 V or 36 V.
The basic requirements for this type of economical E-bike middle motors are: large starting torque, high efficiency, light weight, and a certain overload capacity. This will meet the user's daily use requirements. In addition to the common inner rotor motor driving the wheel through chain drive or direct friction, the outer rotor DC motor can be installed in the middle of the wheel, and the hub is directly driven by the planetary gear reduction mechanism. This motor is also called a hub motor.
This economical E-bike middle motor has the advantages of short transmission chain, high efficiency and compact structure. In addition to the permanent magnetic field, the excitation mode of a DC motor can also be a series excitation. The series-excited DC motor has soft working characteristics, good speed regulation performance, large starting torque and more and more applications.