1. Field of the Invention
This invention relates generally to wind turbines and methods of operation thereof for producing energy and, more particularly to a wind turbine having a circular rotor wheel formed of concentric inner and outer rings with adjustable elliptical blades extending therebetween, the inner and outer rings supported by circumferential arcuate bearing supports connected to yaw mechanisms on a support tower, and the outer ring partially supported on a horizontal rotatable track which rotates to drive power wheels that operate water pumps, air pumps, and/or electrical generators which are selectively engaged or disengaged depending upon the available wind power to maintain rotation of the circular rotor wheel.
2. Background Art
Cook, U.S. Pat. No. 4,350,895 discloses a wind turbine for generation of electricity comprising a large, lightweight wheel attached to a fixed vertical central pylori and oriented to rotate in a vertical plane around a boom having an axis that is substantially horizontal, and pivoted at one end to the pylori. The wind wheel is supported at its rim by a carriage assembly that is constrained to move in a circular horizontal path about the central pylori. The wheel has a cylindrical outer rim and may include one or more perimeter frame structures. The outer surface of the rim is essentially flat in cross section and presents a traction surface for the takeoff of energy from the rim of the wheel. The wheel has a plurality of uniformly spaced radial spindles on which are rolled sails (soft airfoils), which when unfurled catch the wind to provide the rotational motion to the wheel. The carriage assembly may be moved around the pylori by driver means to accommodate for changes in wind direction, or the wind wheel as a whole can be allowed to move freely to assume the preferred wind direction in the manner of a weather vane. The wheel and frame structure are secured to and supports the horizontal boom which lies colinear with the axis of the wheel and projects longitudinally in both directions from the central plane of the wheel. The entire boom structure is supported by means of stays from the perimeter of the rim to the ends of the boom.
Schmidt, U.S. Pat. No. 4,729,716 discloses a wind turbine having a circular turbine wheel with a plurality of soft, furlable and unfurlable airfoils depending between a rim and hub. Each airfoil has associated with it a stepping motor for selectively furling and unfurling the airfoils. The turbine wheel is supported on a carriage which is in turn supported in a cantilevered manner from a central anchor which allows for revolving of the carriage, and therefore the turbine wheel, about the anchor. Control is provided for rotating the turbine wheel into a position upwind and normal to the wind direction. An upstanding pylori mounted on the anchor maintains the turbine wheel in an upright position. The pylori allows for revolving and rotating of the turbine wheel. It also provides for pivoting of the turbine wheel about a generally horizontal axis parallel to and spaced from the plane of the turbine wheel. A plurality of generators are driven by power take-off wheels mounted on the carriage which directly support the turbine wheel rim. Turbine wheel rotational speed control is maintained by varying the number of generators driven by the power take-off wheels and by furling and unfurling the airfoils.
Merswolke, U.S. Published Application No. 2006/0275121 discloses a wind turbine with friction drive power take off on outer rim. The wind turbine has multiple blades that are mounted on a shaft with a ring around a circumference of the blades and tires that are arranged to be in contact or out of contact with the ring. The tires draw generators when the tires are in contact with the ring and the ring is rotating. A controller monitors the wind conditions and controls the turbine to produce electricity or other-energy output or to shut down if the wind falls below a predetermined level.
U.S. Pat. Nos. 5,591,004, 5,632,599, 5,743,712, 5,863,180, and 6,417,578 disclose fluid energy converter wind turbines having a squirrel-cage-like rotor in which blades peripherally distributed about a horizontal axis of rotation are in a plane generally parallel to the axis of rotation. An entry at one end of the rotor is arranged to face the oncoming fluid (air) for receipt thereof. The predominantly axial flow of fluid (air) from the entry is redirected outwardly to the peripherally distributed blades and through the slots therebetween.