Introduction to electric wheel drive technology
The electric wheel drive technology uses four or more independently controlled electric wheels to provide drive torque to the wheels of the vehicle, respectively. There is no mechanical transmission between the power source and the wheel. A typical electric wheel structure is shown in Figure 7-1.
(1) Structure and characteristics of electric wheel drive power system The electric wheel power system is mainly divided into two structural forms: one is an electric wheel system based on an inner rotor type motor; the other is an electric wheel system based on an outer rotor type motor. . Figure 7-2 shows a schematic diagram of the structure of the two electric wheel systems. In Figure (a), the rotor is inside the permanent magnet; in Figure (b) the rotor is outside the permanent magnet.
Figure 7-2 Schematic diagram of electric wheel system structure 1 - tire; 2 - rim; 3 - brake; 4 - stator winding; 5 - permanent magnet; 6 - rotor; 7 - motor controller; 8 - reduction gear;
At present, an electric wheel system based on an inner rotor type motor employs a motor having a high rotation speed and a low torque characteristic. In order to meet the actual speed of the wheel, it is usually necessary to match a corresponding planetary gear reduction mechanism. An electric wheel system based on an outer rotor type motor uses a motor with low speed and high torque characteristics. Since the speed range meets the actual wheel speed requirements, it is usually not necessary to match the speed reduction mechanism, and the wheel is directly driven by the outer rotor of the motor. A typical electric wheel system layout is shown in Figure 7-3. Four electric wheels drive the car as independent drive elements.
