When we accelerate the unbalanced wheel it's angular momentum lead-out has an opposed direction as when we decelerate it. When we accelerate the wheel it's lead-out momentum will go up. And when we decelerate the wheel lead-out momentum will go up as well.

 

By decelerating during only half the rotation we cheat gravity one time. By accelerating only during the other half of the rotation we cheat gravity a second time. Now Energy in => movement out.

 We end up with 3 forces upwards and one downwards per cycle.