Cylindrical wind turbine

Abstract

This invention is a cylindrical turbine incorporating rotating vanes, unlike the fixed vanes utilized in conventional turbines. The rotational position of each vane is continually adjusted, as the turbine turns, to maximize the turbine's energy extraction from the wind.

Description

BACKGROUND OF THE INVENTION

This invention relates to a squirrel-cage-like turbine that can be used to convert wind energy to mechanical power and is conceived as an alternative to conventional propeller-type turbines.

Turbines have long been used to convert directed jets of gas or water into rotary motion. Conventionally, the turbine is a construct of fixed vanes in a circular array about a centered shaft. Such a device requires directional jets in order to rotate. My invention departs from this scheme in that it requires no directional jets, but rotates in the wind by continually adjusting each vane's attack angle to the wind. Furthermore, it has the capability of instantaneously adjusting all vanes to changing wind direction so that energy conversion is maintained at a maximum.

A severe problem with conventional wind turbines is their very high tip velocity, in excess of 180 miles per hour, which leads to low propeller visibility for birds flying in the vicinity. The resultant death of thousands of birds has caused a negative reaction among environmental groups who are demanding curtailed use of this otherwise very desirable power source. My invention addresses this problem by utilizing a squirrel-cage-like turbine with much greater visibility.

SUMMARY OF THE INVENTION

This invention relates to the field of wind turbines. One object of my invention is to provide a cylindrical turbine capable of converting wind energy to mechanical power. Another object is to provide a turbine whose wind-capturing vanes are continually rotated about their long axes, as the turbine turns, to position each at a favorable angle to wind direction. Yet another object of my invention is to provide a mechanical adjustment, suitable for servo control, that allows continuous, simultaneous correction for changing wind direction. Still another object is to provide a wind turbine capable of being supported against the wind by guy cables attached at the top of the support column, thereby reducing mass. A final object is to provide a wind turbine whose visibility to birds is greater than conventional propeller wind turbines, thus reducing bird kill.

DESCRIPTION OF DRAWINGS

FIG. 1 is an elevation view of my invention for converting wind energy to rotary motion suitable to electric power generation.

FIG. 2 is a cross-sectional view taken along 2-2 of FIG. 1.

Referring to the drawings, FIGS. 1 and 2, a rigid structure, cubical in shape, is formed by square tabular members 3 and 4 and posts 5, 6, 7, and 8 bolted together using eight flanges of which 9, 10, 11, 12, 13, and 14 are shown in the Figures. The turbine is housed within this structure and held in position by its axle 15, radial bearing 16 bolted to member 3 and radial/thrust bearing 17 bolted to member 4. The turbine is formed by two planar, circular plates 20 and 21 joined to axle 15 by bolted flanges 18 and 19. In an evenly spaced, circular array, six elongate, tabular vanes 22, 23, 24, 25, 26, 27 are operationally supported between plates 20 and 21 by inset bearings, the mechanics of vane 25 is typical. It is grasped at its ends by channel fixtures 32 and 33 which, at their centers, support shafts 28 and 29 aligned with the vane's long axis. These shafts rotate in radial bearing 31 at the upper end and in radial/thrust bearing 30 at the lower end. Additionally, the lower end shaft holds sprocket 37. All identical sprockets 34, 35, 36, 37, 38, and 39 are linked together by endless chain 40. The lower shaft of vane 24 extends below plate 21, where sprocket 41 is attached. Endless chain 44 couples sprocket 42 to sprocket 41. Sprocket 42 and gear 43 constitute a single mechanical unit riding free on axle 15. Sprockets 41 and 42 have a two-to-one tooth ratio, 42 having the lesser number of teeth. Gear 43 meshes with gear 45 whose supporting shaft pierces base member 4 and is driven by a commercial servo unit 47. This unit responds to a wind-direction sensor (not shown in the drawings) located in the wind stream driving the turbine.

In operation, the turbine rotates by its central shaft 15 turning in bearings 16 and 17. In an unchanging wind direction, servo motor 47 is inactive, which locks gears 43 and 45, thereby holding sprocket 42 stationary as the turbine rotates around it. Consider a wind direction from bottom to top of FIG. 2. In an instantaneous moment, the vanes 22 through 27 are in the position shown in FIG. 2. The wind impinging on the vanes induce a clockwise turbine rotation around stationary sprocket 42. The linking of sprocket 41 and 42 causes all vanes to rotate counterclockwise about their long axes at one-half the rotational rate of the turbine. As a result, the orientation of each vane to wind direction is continually adjusted, as the turbine turns, to contribute to the turbine's rotation, save when it is near the position of vane 23 in FIG. 2. A vane is position 23 is parallel to wind direction, an orientation of minimum drag. The chain coupling of the vanes to sprocket 42, hence to servo motor 47 through gears 43 and 45, allows for instantaneous and continuous adjustment of the vanes to changing wind direction. Consider a wind direction change of left to right in FIG. 2. Each vane now requires an instantaneous clockwise rotation of 45 degrees for peak energy conversion. This correction is made, whether or not the turbine is turning, by a 90-degree clockwise rotation of gear 43. The servo motor 47 then remains inactive until a wind direction change necessitates further correction.

Claims

1. A cylindrical turbine for converting wind energy to rotary power comprising a square, tabular base supporting four posts at the corners, said posts supporting, at their upper ends, a top identical to said base, creating a roughly cubical space housing the turbine rotor composed of two identical circular plates affixed at their centers and held by flanges mounted on an axle that turns in bearings centrally bolted to said base and top; two or more (depending on turbine size) elongate, tabular vanes having shafts mounted at each end aligned coincident with said vane's long axis, said shafts held in bearings mounted in a circular, evenly spaced array on the inside surface and near the edge of said circular plates; an identical sprocket, centered on the shaft attached to the base of each vane, said sprockets linked together by an endless chain having minimal slack; a lower shaft of one of the said vanes extending through its bearing to the rotor's underside where on said shaft a sprocket is affixed and linked by an endless chain to a smaller sprocket having one half the number of teeth of its larger companion and centered on, but free to turn independently of, the axle; two meshed gears, one concentrically joined to said smaller sprocket, free of the axle, the second gear mounted on the output shaft of a commercial servo motor installed below the said base.