Vertical axis dual vortex downwind inward flow impulse wind turbine

#The subject invention relates to wind-powered turbines. Wind has been used as a source of power for many years. Windmills historically have been used to grind grain, pump water and provide other forms of mechanical energy. In recent times they have been used to generate electric power. However, windmills typically utilize a blade or air foil which the wind passes over without significantly changing directions.

#Water-powered turbines, on the other hand, are often impulse turbines where the direction of the water is significantly changed as it interacts with the turbine blade. A typical example of this is the pelton turbine. However, impulse turbines have not been used to convert wind energy to electric power.

#In the subject invention, a wind-powered turbine has a housing with an inlet and an outlet. Mounted in the housing is a plurality of spaced-apart stators that are arranged in a fixed annular cylindrical stator array. A plurality of cupped rotors are arranged in an annular cylindrical rotor array which is rotatable about a central axis and fits inside of the stator array. The stators are positioned to cause air which flows around the outer periphery of the stator array to impinge on the rotors. An air handling system causes air entering the housing to flow around the outer periphery of the stator array.

#FIG. 1 is a perspective view of a wind turbine embodying the subject invention.

#FIG. 2 is a perspective view of the wind turbine of FIG. 1 with the housing in a different orientation.

#FIG. 3 is a cross-sectional view, at an enlarged scale, taken along the lines 3-3 in FIG. 2.

#Referring now to FIGS. 1 and 2, a wind-powered turbine 10 comprises a housing 12 with an inlet end 24 containing an inlet 14 and an outlet end 22 containing an outlet 16. In the embodiment illustrated in FIGS. 1-3, the entire inlet end 12a is open to provide the inlet 14, and the entire outlet end 12b is open to provide the outlet 16. The housing 12 is mounted on a turntable 18 which in turn is mounted on top of a tower 20. Referring now also to FIG. 11, the turntable 18 has an outer ring 19 which is attached to the tower 20. The outer ring 20 has a slot 21 formed in its inner periphery. The outer periphery 23 of a cylindrical plate 25 extends into the slot 21. Roller bearings 27 are located between the top, bottom and edge of the plate 25 and the ring 19. Thus, the plate 25 rotates freely and supports the housing against vertical and radial loads. The housing 12 is attached to the plate through struts 29. The struts support the housing 10 sufficiently above the turntable 18 that the turntable has no effect on wind entering the housing. In the embodiment illustrated the struts separate the housing from the turntable by an amount equal to 50% of the height of the inlet 14. The turntable allows complete rotation of the housing 12 so that the inlet can face into the wind. The housing 12 has a larger cross-sectional shape at its outlet end 22 than at its inlet end 24. This causes wind-driven air passing over the housing to accelerate as it moves from the inlet end 24 to the outlet end 22, thereby causing the pressure at the housing outlet 16 to be lower than the pressure at the housing inlet 14. The advantage of this will be more fully explained later. In the embodiment illustrated, the housing is square in cross-section but it could have many other cross-sectional shapes. Preferably the entire housing is symmetrical so that the distance from the inlet end to the outlet end is equal around its entire extent.

#Referring now to FIG. 3, a cylindrical turbine assembly 26 is mounted in the housing between the inlet end and the outlet end. The turbine assembly 26, best seen in FIGS. 4, 6 and 8 includes a plurality of stators 28 which are arranged in an annular cylindrical stator array 30. The stator array is divided into a first section 30a and a second section 30b which are separated from one another. The first stator section is located between an annular upper stator ring 32 and an annular middle stator ring 34 and the second stator section is located between the middle stator ring 34 and an annular lower stator ring 36. The outer periphery of the middle stator ring contains a rounded bull nose 37 which projects outwardly from the stators to assist in splitting air entering the turbine assembly 26 between the first and second Sections 30a, 30b. Each stator 28 has a hole 38 extending centrally through it, and a rod 40, which passes through the hole 38, is attached to the upper, middle and lower stator rings. Thus, the rod joins the stators and stator rings into an integral unit. The stators are tear-drop shaped and are symmetrical side to side. They are angled to direct air entering the turbine in the desired manner, as will be explained later. Pins 42 extend between the tops and bottoms of the stators into the stator rings to prevent the stators from rotating on the rods 40, FIG. 7. The number of stators, and thus the spacing between them, is set to cause the air entering the turbine assembly 26 to be distributed relatively equally around the entire outer periphery of the stator array 30.

#The turbine assembly 26 also includes a plurality of cupped rotors 50 which are arranged in an annular rotor array 52 which fits immediately inside of the stator array 30. The rotors have an entry end and an opposed exit end such that air passing over each stator impinges on the entry end of an associated rotor, passes along the entire cupped face of the rotor and exits the exit end of this rotor. The cupped shape of the rotors causes air striking them to change direction much as the rotors do in a pelton hydraulic turbine. In the embodiment illustrated, the air exits the rotors at approximately 164 degrees relative where it enters them, but increasing or decreasing this angle may increase the efficiency of the turbine. There is one rotor for each stator and the stators and rotors are positioned such that air directed by each stator impinges substantially on the cupped side of an associated rotor. In the embodiment illustrated the rotors are oriented such that a line A, which connects their tips, extends through the center of the rotor array, FIG. 4. The rotor array also is divided into a first section 52a and a second section 52b, which are separated from one another.