Electric scooters have become very popular, it is a convent way to commute and get around in congested urban areas. The driving force behind the electric scooter is the Hub motor. The hub motor is exactly that, a motor in a hub of a wheel. Hub motors can be placed in the front and/or rear of the scooter.
The type of motor that is used in this hub is called a Brushless DC outrunner motor. Outrunner means the outer part (wheel) rotates, opposed to inrunners, which have a rotating inner part. The part that moves is called the rotor and the part that is stationary is called the stator. In Brushless motors, DC voltage is applied to coils without the aid of brushes. Brushes have long been used as a method to provide power to the rotor.
In a nutshell, the hub motor has two types of magnets, permanent and electromagnet. The electromagnet functions like a permanent magnet, with the added feature that it can be switched on and off electronically. The coils are switched on and off in a sequential manner causing the adjacent permanent magnets to attract or repel, resulting in rotor (wheel) rotation.
The electronic switching is generated by the scooter’s controller.
See wheel rotation