wheel
Circular unit turning around an axle; it supports the weight of the vehicle and transmits the thrust, steering and braking actions.
disk 
A part of the rim that is fixed at its center on the wheel’s axle.
rim 
Metal circle constituting the wheel’s circumference and on which the tire is mounted.
rim flange 
Edge of the rim providing lateral support to the tire bead so that it adheres solidly to it.