1. Rotor: Serving as the motor's power output component, it can be designed with either an inner-rotor or outer-rotor structure. The outer-rotor type connects directly to the wheel and rotates with it, whereas the inner-rotor type requires a reduction mechanism to convert high-speed rotation into the low-speed, high-torque motion suitable for driving the wheel.
2. Stator: Fixed within the wheel housing, it consists of three-phase or multi-phase windings-made of layered enameled wire-embedded in the slots of a low-loss magnetic core; driven by AC power from an inverter, it generates a rotating magnetic field.
3. Reduction Mechanism: Inner-rotor in-wheel motors may be equipped with reduction mechanisms, such as planetary gears or worm gears, to ensure the efficient transfer of torque from the high-speed motor to the wheel.
4. Cooling System: Employs air, liquid, or hybrid cooling methods to maintain stable motor temperatures during continuous operation, preventing performance degradation or damage caused by overheating.
5. Bearing System: High-precision, high-load-capacity bearings support the relative motion between the rotor shaft and the stator, ensuring smooth operation and minimizing frictional losses.
6. Electrical Connections and Controller Integration: After receiving DC power from the vehicle's battery, the motor uses a controller to convert it into controllable AC power, adjusting voltage, frequency, and phase to regulate motor speed and torque.
7. Sensors and Communication Modules: Modern in-wheel motors are equipped with devices such as speed sensors, temperature sensors, and even gyroscopes to monitor motor status in real-time and transmit data to the vehicle control system, enabling precise power distribution and fault diagnosis.
8. Wheel Hub Body and Braking Components: The in-wheel motor must be compatible with existing rim and tire assemblies and integrate with the braking system; some designs incorporate brake discs or drum brakes directly into the motor's internal or external structure.