Actually, Schubkurbel looks like a Piston..
We'll leave it to Motor Vessel Smith to explain..
Actually, “Crank†in this context, “kurbel†being the operative part.
Crank kinematics is the system of linkage that controls the cyclic pitch angles of the blades.
Here is what it looks like after removal. A size 36 VSP has a blade circle diameter of 3.6 meters; to give you an idea of the size—and why it takes six people to handle it in one piece.