How does a hub motor differ from an ordinary motor?

The basic idea is just the same. In an ordinary motor, you have a hollow, outer, ring-shaped permanent magnet that stays static (sometimes called the?stator) and an inner metallic core that rotates inside it (called the?rotor). The spinning rotor has an?axle?running through the middle that you use to drive a machine. In this case the rotor and the stator has swapped the roles i.e., the static rotor stays still while the stator spins around it.?SO basically, you connect the central, normally rotating axle to the static frame of a bicycle or the chassis of a car. When you switch on the power, the outer part of the motor rotates, becoming a wheel (or wheels) that powers the vehicle forward.

Hub motors typically achieve more torque by increasing the hub size quite significantly (a bigger stator and rotor make more torque than smaller ones). Some hub motors boost their torque with internal gearboxes (typically an arrangement of planetary gear box?in between the stator and the rotor). Bigger torque brings an added problem: you need to be sure the rest of your wheel is strong enough to cope with the twisting forces a hub motor can deliver, otherwise the motor could simply bend the spokes instead of moving you along the ground.