my door knob its has a wheel and axle inside like there are two axle and one wheel and the axle is coverd by the knob so when u turn the knob or push it down the wheel in the middle will mover henceforth opening the door.(iam not sure if my explanation is detailed...^-^)

another wheel and axle is the clock on the wall the axle is smaller than the wheel in diameter.The axle is in the clock , in the concealed part.

a lever is a crowbar. I dont know why is it in my house but its just in there.when we use it to open crates that are tightly sealed during that moment the crowbard is counted a lever. by the lucky the minituare schnauzer .