Why is a Ferris wheel a wheel and axle?

The axle of a Ferris wheel is the part that the wheel spins around. It is in the center of the whole construction. So when you say Ferris wheel you don't say Ferris wheel and axle, you just say Ferris wheel.
... or the same "why" is when folks say" WOKEN UP (dangling particple...inncorrect use)... instead of the correct word..."Awaken" ... " I was "woken up" (Awakend) by the banging of trash can lids being thrown..."