BACKGROUND OF THE INVENTION

1) Field of the Invention

The present invention relates to an improved segmented self-positioning wind turbine assembly having self-positioning airfoils for generating electricity in response to the movement of atmospheric wind.

2) Description of Related Art

Windmills have been used for many generations for the purpose of pumping water from the ground and for generating electricity. A basic advantage of the windmill is that it uses the power of atmospheric wind to rotate a wheel having radially extending blades. This rotary movement may be converted into various useful purposes. For example, wind turbines in the form of propellers mounted on towers have been placed in areas where steady winds are prevalent, and the wind turbines are used to generate electricity. An electrical generator is usually positioned near the axis of rotation of the propellers, adding the weight of the generator to the upper portion of the mast of the assembly. The blades of the conventional large wind turbines are large and made of expensive rigid material and are constructed to have the blades extend radially from a central hub, with no extra support at the outer tips of the blades. The conventional wind turbine blades rotate at a high rate of revolutions and must withstand both the centrifugal forces generated by the fast revolution of the blades and the cantilever bending forces applied to the blades by the wind. Since the outer portions of the blades usually move at a very high velocity and are engaged by strong winds, the larger the blades the stronger they must be and the more expensive they become. Thus, there is a practical limit as to the length and width of the blades.

Another wind turbine type has rigid propellers that appear to be rigidly mounted to circular perimeter rims that support the outer ends of the propellers, as shown in U.S. Pat. Nos. 1,233,232 and 6,064,123. Rubber tires or other rotary objects are placed in positions to engage the outer rim so as to rotate the rubber tires, with the driven tires rotating the rotor of a generator. Thus, the rotation of the wind turbine is used to generate electricity. A disadvantage of the rigid propeller design is its ability to handle the fact that the closer to the tip or perimeter of the blade you get, the faster the blade is moving through the air and so the greater the apparent wind angle is. Thus, the blade needs to be turned further at the tips than at the hub so that there is a twist along its length. The blade's optimal angle of attack can be determined by apparent wind direction. The apparent wind direction changes as the speed of the blade increases, even when a uniform wind velocity exists across the wind turbine swept area. Blades with a twist are more expensive to make. Traditional wind turbine blades themselves are also very expensive to maintain and replace.

One of the advantages of a turbine wheel with a perimeter rim is that the electrical generator(s) may be positioned at the rim at the lower arc of rotation of the rim where the generators are closer to the ground or other low supporting surface to remove the weight of the generator from the upper portion of the mast. Also, the position of the generator at a rim of the turbine wheel gives more access for installation, maintenance, repair and replacement of the generator. However, if the perimeter rim of the wind turbine wobbles during operation, it may be difficult to maintain the generator in proper alignment with the rim and it appears likely that stress between the generator and the turbine wheel will occur. Also, if multiple ones of the generators are placed in operative locations about an arc of the rim of the turbine, the potential problems caused by the wobbling rim appear likely to be more prevalent.

Further, it is advantageous for the rim to be as circular as possible so to reduce vibrations and to maintain consistent contact with the generator. To assist with maintaining a circular rim, guide wires can be included to extend from the perimeter of the rim to the hub to support the rim. However, the guide wires can create drag and reduce the output of the wind turbine. It would be advantageous to reduce this drag caused by the guide wires.

Accordingly, it is an object of the present invention to provide a wind turbine that adjusts the angle of attack top seek optimization of the rotation's energy of the wind turbine.

It is another object of the present invention to create a wind turbine with a perimeter allowing a generator to be positioned along the lower portion of the perimeter.

It is another object of the present invention to provide a wind turbine with auto-adjusting twist to seek optimization in response to wind direction and speed.

It is another object of the present invention to reduce or eliminate the need for complicated blade pitch control system and vanes on one embodiment.

SUMMARY OF THE INVENTION

The above objectives are accomplished according to the present invention by providing a wind turbine having a mast, hub, cables, and rim comprising: a plurality of airfoils carried by one or more cables and disposed between the hub and the rim; wherein each airfoil includes a leading edge and a trailing edge and is symmetrical along a bisect from the leading edge to the trailing edge; a vane attached to each airfoil having a shaft and fin so that the airfoil has an angle of attack in the range of 10° and 12°; wherein each airfoil has a slightly different angle of attack relative to the adjacent airfoil on the cable. In one embodiment, the camber line and the chord line are superimposed. The chord length can be in the range of 5 inches to 10 inches in one embodiment and about 7 inches in one embodiment.

The invention can include airfoils having a length along the direction of the cable of between 4 feet and 12 feet, in one embodiment. Sailets can be attached to the rim that can extend between 6 feet and 12 feet from the exterior of the rim wherein the sailets can be fixed pitch or variable pitch. Spacers can be included between each airfoil to prevent the airfoil from interfering with the adjacent airfoil. Each airfoil can include an end cap. A stop, such as a pin, can be included in each airfoil to prevent the airfoil from rotating a predetermined amount such as less than 90°. The airfoil can be made from high performance vinyl ester resin, 40% unidirectional fiberglass reinforcement, 17% continuous fiberglass mat, balance proprietary resin mixture, UV inhibitors, color of choice, and a surfacing protection veil.

The invention can include a wind turbine wheel having a hub, a rim and a cable extending between the hub and the rim; a set of airfoils rotatably carried by the cable and disposed between the hub and the rim; a cinch attached to the cable and disposed between adjacent airfoils; and, an upturned section included in at least one airfoil in the set of airfoils and disposed at a trailing edge of the airfoil wherein each airfoil has a different angle of attack relative to an adjacent airfoil. An inner cable can extend between a distal end of the hub and the rim; and, a set of inner airfoils can be carried by the inner cable. An outer cable can extend between a distal end of the hub and the rim; and, a set of outer airfoils can be carried by the outer cable.

The wind turbine can include a first airfoil adjacent to the hub having a first length; a second airfoil adjacent to the rim having a second length; wherein the first length is less than the second length. An intermediate airfoil can have a length between the first length and the second length. A spacer assembly can be disposed between adjacent airfoils. A resilient member can be included in the spacer assembly. A washer can be included in the spacer assembly. The airfoils in the set of airfoils can have a length in a range of 2 feet to 12 feet. The airfoils in the set of air foils can have a shortest airfoil having a length of about 2 feet with the remaining airfoils having lengths longer. A vane can be attached to at least one airfoil in the set of airfoils.

The airfoils can include material selected from the group consisting of high-performance vinyl ester resin, 40% unidirectional fiberglass reinforcement, 17% continuous fiberglass mat, resin mixture, UV inhibitors, pigments, surfacing coatings and any combination. The wind turbine can include a generator having a generator wheel configured to engage the rim and disposed below the rim.

