Mostly flat type, but the motor type, structure form, drive mode is different, the classification is as follows.
According to the type of motor classification: at present there are four main types of motors used in electric wheel hubs, that is permanent magnet motor (PM), asynchronous motor (IM), switched reluctance motor (SRM) and transverse flux motor (TFM). Among them, the application of permanent magnet motor is the most common, and the transverse flux motor is a kind of very competitive low speed and high torque motor.
Classified according to its structural form: from the main magnetic path, it includes all three basic forms of radial magnetic field (radial), axial magnetic field (axial) and transverse magnetic flux (transverse). In terms of movement, there are also internal rotor, outer rotor and double rotor. Among them, the double rotor structure is the most innovative. The inner rotor is active, the outer rotor is driven, and the two transmits power through a set of planetary gears, so that the reverse rotation is made, and the speed of the magnetic field cutting the conductor is the sum of the speed of the inner and outer rotors. Obviously, the smart combination of speed superposition and mechanical linkage not only brings the relaxation space to the motor design, but also plays a role in releasing the load disturbance, stabilizing the impact load and effectively protecting the battery.
Classified according to the driving mode: when driving directly, the motor adopts the outer rotor structure, that is, the rotor directly drives the wheel hub to rotate, so the speed is low. Correspondingly, the indirect drive, the motor is mostly internal rotor structure, higher speed, through the planetary gear ring gear mechanism to achieve slow down, leading to wheel rotation, and therefore also known as the "deceleration drive.".
According to the speed of rotation classification: wheel motor and high speed and low speed points, but the corresponding speed range is not clearly defined, depending on the application object is different. Usually, only when the driving mode, high speed and low speed scope is relatively accurate meaning, which directly corresponds to the low speed motor drive (large volume, multiple power supplies, low density, low noise), and indirect drive is corresponding to the high speed motor (small volume, less cost and high power density high noise).http://www.neo-powers.com/