From the perspective of the main magnetic flux path, it includes all three basic forms of radial magnetic field (radial), axial magnetic field (axial), and transverse magnetic flux (transverse). From the perspective of movement, there are also inner rotors, outer rotors and double rotors. Among them, the double-rotor structure is the most innovative. The inner rotor is active, and the outer rotor is driven. The two transmit power through a set of planetary gears to achieve reverse rotation, so that the magnetic field cuts the conductor at the sum of the speeds of the inner and outer rotors. Obviously, this ingenious combination of speed superposition and mechanical linkage not only brings room for relaxation to the motor design, but also plays a role in slowing down load disturbances, smoothing impact loads, and effectively protecting the battery.

When driving directly, the motor mostly adopts an outer rotor structure, that is, the rotor directly drives the hub to rotate, so the speed is low. Corresponding to this, in indirect drive, the motor is mostly an inner rotor structure with a higher speed. The planetary gear plus ring gear is used to achieve deceleration and drive the hub to rotate, so it is also called deceleration drive.

In-wheel hub motors are also divided into high-speed and low-speed, but the corresponding speed range is not clearly defined, depending on the application object. Generally, only after the driving mode is determined, the definition of the high and low speed ranges has a relatively accurate meaning, that is, direct drive generally corresponds to a low-speed motor (large volume, more consumables, low power density, and low noise), while indirect drive has more Corresponding to high-speed motors (small size, less consumables, high power density, high noise).