1. Field of the Invention
This invention relates to an electricity generating device and more specifically to one that is powered by the force of the wind.
2. Description of Prior Art
Air pressure at the earth's surface is 14.7 lbs./square inch. This is about a metric ton/square foot. So a cubic foot of air weighs about a metric ton. If this cubic foot of air is made to move 10 miles/hour then the power developed is over 56 horse-power. So theoretically wind energy can supply all of man's energy needs. There has been some progress towards extracting this energy. In order to do so at 100% efficiency a perfect vacuum must somehow be contrasted with normal air pressure. Airfoils are used to cause a mild pressure difference which is enough to lift aircraft, and in the form of a propeller to spin wind turbines to produce electricity.
Wind turbine efficiency is severely limited since a great deal of the wind energy blows through the propeller arc without affecting performance. Sails have been tried (see U.S. Pat. No. 7,157,805 to Mooring) and this is a step forward since all the kinetic energy of the wind may be processed by the device. Mooring points out the wind is forever changing its velocity. He mounts a square rig sail on a pole which serves as a long lever. As the sail is made to swing back and forth by the wind the lever is made to operate gears and springs to operate an electric generator.
But the problem remains to increase as much as possible the coefficient of drag and/or lift so more power can be produced over the same fromtal area of whatever shaped energy collector is atop the pole. Accordingly, it is the object of this invention to efficiently convert the absolute pressure energy of the wind into electricity.
A Flettner Rotor is mounted atop a pole, with attendant motor. The pole serves as a lever which is made to operate a mechanical transmission on the ground, which in turn is made to operate a generator. Various hydraulic systems are also feasable such as described in my U.S. Pat. Nos. 6,781,253 and 7,043,904. With the use of a Flettner Rotor the coefficient of lift is greatly increased and therefor leads to an increase in power output compared to using a propeller or sail.
Power is only produced by this invention when the force on the lever is made to vary. There may be times when the wind is not gusting. But by varying the speed of the motor the lift force will be varied. The Rotor should have only a minimum mass so it is easier to accellerate and decellerate its spin.
The attainment of the foregoing and related objects, advantages and features of the invention should be more readily apparent to those skilled in the relevant arts indicated, after review of the following more detailed description of the invention, taken together with the drawings in which:
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In operation, referring to
Wind velocity varies and as this velocity decreases the action of tension spring 23 tends to restore pole 1 to a vertical position causing electrical generator 17 to produce further power.
If this wind velocity variation is not sufficient to produce maximum power output the solenoid may be energized alternately with motor 11 to vary the speed of the Flettner Rotor 2.