US Patent 7665966 Flow-controlled wind rotor

A flow-controlled wind motor rotor has one or more blades which are parallel to a central vertical axis. The blades are orientable to the direction of the wind. The rotor is equipped with a wind vane for detecting of a wind direction and also with a primary control mechanism which is controlled by the wind vane, and a secondary control mechanism, which is subordinate to the first control mechanism. The primary control mechanism is driven by a V-belt, while the secondary control mechanism is driven by a stepping engine with a worm gear.