Patent ID: 7581926

Claim:
A fluid-flow power generating system comprising: a turbine mounted on a structure that is held stationary with reference to a fluid flow; said turbine having a rotor comprised of a rotor hub and a number of blades, said rotor being positioned on said structure such that said rotor is in alignment with fluid flow direction; each of said blades having a root blade with a hub end attached to said rotor hub and an extender blade that is variable in length to provide a variable diameter rotor; said extender blade capable of extension and retraction of a radius of sweep of said rotor blade to increase and decrease a cross-sectional area of fluid flow swept by said rotor blade; an adjusting device for said rotor blade including a servomotor-controlled rack gear and pinion gear actuation mechanism, said rack gear being attached to said extender blade; said servomotor-controlled rack gear and pinion gear actuation mechanism including a first servomotor and first pinion engaging gear on one side of said rack gear and a second servomotor and pinion engaging gear on a side opposite to said one side of said rack gear; said first and second servomotors being anchored at said hub end of said root blade; said root blade has spaced apart ribs defining an airfoil contour of said root blade and a lengthwise front spar and rear spar to which said ribs are attached; and said extender blade is housed within said root blade with bearings, which allow said extender blade to move within a space between said front and rear spars.