CA1286995C - Vertical axis wind turbine - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A cross-wind, axis-type, wind turbine is provided herein, which includes four wind driven airfoil blades pivotally con-nected between upper and lower sets of support spokes supported on a rotating vertical column so that the blades are upwardly inclined towards the column axis to produce an accelerated down-wardly swirling air flow in the turbine interior. The lower spokes are airfoil-shaped to draw wind into the turbine further to accelerate the air flow in the turbine for improved blade efficiency. A feedback control arrangement, which is responsive to changes in wind speed or direction, adjusts the blade angles to the wind for optimum efficiency by virtue of a rack and pinion assembly connecting each blade to a center plate through con-necting rods extending radially through each upper spoke. The center plate is mounted within the column on a control shaft that includes an offset portion that pivots during blade rotation about the column, or when rotated by a wind vane, to vary the radial positions of the plate and thereby the blades through the rack connections. Alternatively, a pair of weights radially movable within the lower spokes by centrific force in response to variations in wind velocity can be connected to pivot the control shaft to adjust the blade angles. Each blade includes a series of troughs formed equispaced to each other along the blade length that are respectively tapered towards the leading edge to cause wind entering the troughs to diverge and decelerate for maximum wind energy transfer to the blades.

Description

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The present invention generally relates to ver~ical, cross-wind axis wind turbines having plural ~ind driven blades with variab]y adjusted orientation to incident wind.

~Yind axis and cross-wind axis turbines are the ~-predominant wind turbines presently in use and under study. ~ wind axis turbine includes a number of blades mounted for rotation about a central horizontal column having an axis of rotation that must be closely aligned witll the wind to produce power efficiently. Since wind direction tends to vary over time at most sites, high efficierlcy can be achieved only if the horizontal axis can be rotated to provide the close alignment. However, structure for rotating the horizontal axis into the wind tends to be expensive, resulting in poor power-cost ratios for very high power wind turbines.
Wind driven vertical turbines typically include an assembly of airfoils or blades mounted for wind-driven structure. Vertical wind driven turbines respond to wind from any direction without shift of the column or base stLucture thereof. ~lowever, to improve blade ~5 efficiency, by obtaining a more favorable blade angle of attclck to the wind, it is often necessary to rotate each blade about an individual axis thereof as the assembly rotates about the vertical column. Known structures sucll as a type disclosed in ~. S. Patent No. 4,049,362 to R~n~er, a ring gear arrangement as disclosed in ~. S.

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~2~36995 Pa~ent 3,9~3,072 to Quinn, or a circular track and bearing arrangement as disclosed in German Patent 7~2,7~ to ~lartwagner. The blade angle oE attack control structures disclosed in the aforesaid patents also vary the blade in response to changes in wind speed or velocity.
The foregoing blade control arrangements have a number of disadvantages, one being that a hiyher than a~erage on site wind velocity is often necessary to overcome inertia of the ring gear, gear train or circular track mechanisms to initiate turning of the blades. Also, to maintain blade rotation, a certain amount of wind power is necessary to overcome inertia of the ring gear, gear train or circular track mechanisms ! 15 to initiate turning of the blades. Also, to maintain blade rotation, a certain among of wind power is necessary to overcome friction generated by these blade control mechanisms, adversely affecting power/cost -ratios. Further, since gears employed in these prior art mecllanisms rotate constantly, in wearing contact with each other, and operate under variable wind velocity conditions, frequent maintenance and/or replacement may be necessary, particularly after periods of excessive wind velocities. To generate sufficient wind uower to achieve economical operation, vertical wind turbines generally include large airfoils. Devices to control such airfoils can be very costly.
Another problem associated with certain known relatively high efficiency cross-wind axis wind turbines is that the blades have complex shapes, thus being expensive to manufacture. Other turbines of this type are inefficient because the blades are not designed so they are always oriented to the wind for op,timal wind '' ' '' '' .< I ~ , , :

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energy absorption.
In the fields of wind turbines and vertical-axis--types in general, the airfoil or blades must perform under the condition of wind pressure reversal for each revolution of the turbine and therewithal in a given design shape the blade must therein per-form well. However, this is not always the situation; often a trade-off on performance has been required within the blade design shape to give better performance on wind flows on one side than on the other side.
An example of a vertical axis wind turbine with an airfoil design that is far better suited for deriving energy from one side of an airfoil blade than the other side, is U.S. Patent No.
4,130,380 by Kaiser. In addition, there are designs that use large massive structures in an attempt to improve the channelling and compressing of wind flows, namely in such patents as U.S.
Patent No. 4,490,623 by Goedecke or Canadian Patent No. 1,027,052 by ~aumgartner. Yet another type of design used for an improve-ment of wlnd flows is the use of an end plate angled on the blade ends, which would give some improvement on one side over the other side thereof, the main function being to keep the air flows from merging on the blade ends and a stated control means of turbine speed, as provided by U.S. Patent No. 4,255,085 by Evans.
Another design which has been tried involves the use of flexible rubber or plastic blades which bend into a contour shape, to adjust the wind flows to provide circular rotation about the axis, as provided in German Patent No. 28270044 by Lagarde. This .

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design would, however, have a stability problem, e.g., of the blades may get out of synchronous balance with each other and ~ would be subject to fatigue of the blade materials. The use of 5 troughs has been attempted on ship screws and rudders, as indi-cated by U.S. Patent No. 1,465,593 by Barrett et al, and French Patent by Jacquemin 773,033 ~which provide a single-sided trough), in British Patent No. 838,868 and U.S. Patent No.

2,962,101 (which provide ship screws), U.S. Patent No. 2,899,128 by Vaghi (which provide an air blower), and U.S. Patent No.
2,013,473 by Meyer (which provide a fluid propeller and fan blade). U.S. Patent No. 1,861,065 by Poot described a propeller screw having serrated blades.
Vertical, wind-driven turbines typically include an assembly of airfoil blades mounted to a wind-driven shaft of a supporting axis-type structure, with a capability to respond to wind flows deriving from any direction without a shifting of the structural ¦ mass. One effect of wind flows on the airfoils causes circula-tory vertical travel about its central path. In addition, a tur-bulent air flow about the airfoil surface derived from a rever-sing of pressure flows upon the airfoil blades occurs. Another problem of airfoils in general requires the slowing of the air-flows on the wind incident side of the blades, while substan-tially simultaneously requiring an increase in the airflows on the other side of the airfoil. A useful type of airfoil-blade for vertical axis wind turbines that is well suited to the pro-blem of wind pressure reversal, should be an airfoil design that :,.
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performs equally well to the high and low pressure changes on the blades upon exposure of wind thereon. Another desired affect is to cause circulatory travel about a vertical axis to provide an 5 improvement of energy transfer in lower wind velocities onto the blades. Another aim would be to cause the wind flow to slide ``~ into the contouring troughs and in so doing to slow-down and modify the wind flows to provide fGr optimizing the transfer of wind energies to the turbine blades, thereby to provide a greater output of total energy. A number of wind turbines are presently in use which would need to be improved by the provision of aero-dynamic airfoil blades that are better suited for the transferr-ing of energy velocities of winds onto the blades for generating ;- sufficient power. This aim is to achieve economical operations, so as to overcome the present cost-to-power ratios that adversely affect a useful development of wind turbines.
The best mode for achieving these effects is provided by a - uniquely-shaped blade having a series of contour troughs along its length for channelizing of wind flows therein, to maximi7e 20 the transferring of energies to the blades. The troughs are respectively staggered in relation to each other along the blade length so that each trough defines an airfoil-shaped blade seg-ments within a triangulation of intersecting troughs along the blade length. In such manner, the wind currents striking the blade surface will diverge and decelerate as they flow through each trough towards the trailing edge. This effects a trans-ferring of the wind energies by first slowing airflows on the .~ .
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9~s high pressure wind incident side, thereby to channel within the troughs to effect a merging of the flows on the opposite side of the blade (the low pressure side of the wind flows) to cause a dropping of the wind flows. This causes a pressure drop, which speeds up the airflows by the lowering of the incurring pressures within the trough. The preferred range of the ratio of width ~W), to a depth of each trough is approximately ~:1 to 8:1, with 5:1 being best to minimize the total surface area of depths and crests of the troughs and therein also to maintain the optimal design to coact to modify of the wind-air flows on both sides of the blade. This causes a blending and a merging of the wind-air flows, thereby to equalize pressures and velocities, to cause a minimizing of a trailing vortex of the blade wake. There are several designs of the blade to accomplish these effects. In such blade, the highest pressure of the high pressure side of ~-~
blade (wind incident side) is also the highest pressure of the low pressure side. The other side of the blade having the lowèst pressure on the trailing edge provides the lowest pressure on the trailing edge of the wind incident side of the blade. This brings about a merging of airflow within the merging wake of the blade. This is a result of the design of the trough shape using the "laws of Bernoullis flow dynamics" to improve the performànce of the blades efficiency and drag coefficient.
It is accordingly an object of a broad aspect of this inven-tion to provide a vertical wind turbine having a low inertia blade control mechanism for controlling both the speed and -~ ' ~
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orientation of plural vertical blades under variable wind con~
ditions to maximize conversion of wind power to usable power.
An object of another aspect of this invention is to provide a wind turbine having a blade control mechanism that is econo-mical in design and is capable of reliable operation in rugged and hostile environments, as occurs in on-site wind locations.
An object of yet another aspect of this invention is to pro-vide for controlled orientation of blades in the vertical wind turbine to regulate angular velocity of the blades and hence conversion efficiency of the turbine.
An object of still a further aspect of this invention is to provide a wind turbine that is simple, reliable and inexpensive to construct.
By one broad aspect of this invention, a wind-driven turbine of the vertical axis type is provided comprising (a) a support base, (b) a generally vertical column rotatably mounted to the .
support base; (c) upper and lower support means respectively mounted on the column for rotation therewith; (d) a plurality of wind driven blades connected between the upper and lower support means for rotation about the column, each blade being indivi-dually rotatable about a blade axis extending longitudinally through the blade to vary a blade angle of attack thereof rela-tive to wind velocity during rotation about the column; and (e) control means for variably adjusting angles of attack of each blade to incident wind, the control means including a connecting rod means having a drive means for rotating each blade about the ~ ' ' '' - , . - ' ' ' : ' ~

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associated blade axis in response to radial movement of the con-necting rod means and control shaft pivotally mounted within the column and having a first shaft portion connected to the connect-ing rod means and a second shaft portion radially offset from thefirst shaft portion and pivotally connected radially to displace the first portion and thereby the connecting rod means to vary the blade angies of attack during rotation about the column, wherein the upper support means includes four substantially-identical spokes extending substantially-horizontally radially ; from the column, the connecting rod means including a connecting rod extending through each upper spoke for connection of the :
drive means to a driven means mounted on a portion of a shaft passing through each biade, wherein the control means urther includes a plate to which three of the connecting rods are pivo-tally affixed by spherical bearing means respectively spaced 90 ;
from each other, and a center spherical bearing mounted in the plate to receive the first shaft portion therein, the fourth con-necting rod being non-rotatably affixed to the plate periphery, enabling radial displacement of the plate and connecting rods in a generally-horizontal plane, wherein the control means further includes a cylindrical bearing member rotatably mounted withln - the column on races with the offset second shaft portion being . .
pivotally mounted within the cylindrical bearing by means of a pivot pin affixed to an inner surface of the bearing mounted cylinder.

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- 8a -Such turbine further preferably includes a compression spring extending under the pivot pin on the second shaft portion to contact the inner cylinder to bias the offset portion.
The linearity-dxiven blade means preferably includes a rack affixed to the outer end of each connecting rod, the driven means including a pinion meshing with teeth provided on each rack to cause radial displacement of the connecting rods through the alignment plate.
The turbine preferably also includes a wind vane structure affixed to the first shaft portion above the upper spokes, the vane causing rotational movement of the control shaft in response to variations in wind direction, with wind velocity thereby caus-ing pivotal arc movement of the second shaft portion and radial displacement of each connecting rod through the control plate radially to displace each rack to change the blade attack angles.
Such wind vane preferably includes a low, relatively-thick, counter weight in the forward segment, and a thin, relatively-high, rearward segment extending horizontally from the first shaft portion, and an air scoop located on a vertical face of the rear segment, the air scoop having a curved wall defining a large upwind opening and a smaller downwind opening enabling wind to - enter the scoop to strike the vertical face and thereby to rotate the vane into the wind controlling the feedback response. The lower support means preferably includes four identical spokes, each extending horizontally and radially from its respective -~
attachment to the column and spaced 90 from each other.

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- 8b -The turbine further preferably includes a pair of weights respectively mounted within an interior area of two diame-trically-opposed lower spokes on roller bearing means, enabling the weights to move radially with respect to the column through the spokes in response to variations in centrifugal force caused by changes in wind velocity acting upon the blades, and means interconnecting each weight to pivot the offset second shaft portion to adjust the blade angles in response to movement of the weights. Such interconnecting means preferably includes cable means attached to each weight and extending upwardly through the column for connection to a hollow tubular member located in ver-tical, coaxial alignment with the cylinder to receive a lower inclined portion of the second shaft portion through an opening formed in a side wall of the tubular member, the opening carrying ; a roller rotatably mounted to an upper edge of the opening to engage an inclined surface of the inclined rod portion, the -'! tubular member being vertically movable in response to radial :"
displacement of the weights, causing the roller to travel along the inclined surface to thereby pivot the offset portion causing blade adjustment. The turbine preferably further includes an output shaft interconnected to and coaxially bearing mounted within the column support for rotational movement therewith, the output shaft projecting downwardly from within the supporting column tube to deliver rotative torque to a means converting torque to usable power.

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- 8c -In the turbine of aspects of this invention, the ratio of the length of the upper spoke to the length of the lower spoke is approximately 2:3 and the height of the column is equal, approxi-mately, to the sum of the diameters of the upper and lower spoke sets, causing each blade to be upwardly inclined towards the cen-tral vertical axis of the column by a blade inclination angle of approximately 6 as measured between a vertical plane extending tangentially through an outer end of the lower spoke and the blade axis. The blades thereby cause air entering the interior of the turbine from an upper section thereof to rotate downward about the column to produce a swirling accelerated air flow -imparting additional wind energy to the blades. Each lower spoke preferably is airfoil-shaped, causing wind to flow upwardly into the turbine interior through the spokes to flow with the acceler-ated swirling air flow obtained with the inclined blades for -improved efficiency. The upper spokes preferably are mounted to the column so as to be circumferentially advanced with respect to ~, .
the lower spokes by approximately 3~ incline angle divided by two, thereby to obtain a higher angle of attack at the upper blade portions relative to the angle of attack of the lower blade portions.
- In the turbine of an aspect of this invention, the ratio of the diameter of the upper spoke set relative to the lower spoke ~5 set is approximately 1:2 to 4:5~ The height of the column pre-ferably is at least approximately equal to the diameter of the -.
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- ~d -lower spoke set up to and including the sum of the diameters of the upper and lower spoke sets.
In the accompanying drawings, Figure 1 is a perspective view of a wind turbine constructed . in accordance with an embodiment of the invention;
Figures 2 and 3 are schematic sectional views, taken along lines 2-2 and 3-3 of Figure 1 of the blade angle of attack for , the blade upper and lower portions;
, 10 Figure 4 is a detailed, partial cross-sectional view of an :~ offset control mechanism located in an upper portion of the tur-bine for adjusting the blade attack angles during blade rotation ¦ about a central vertical axis of turbine;
¦ Figure 5 is a sectional view taken along the line 5-5, .
Figure 4 of a pivotal connection between an offset shaft portion 1 of the control mechanism and the rotating support column to vary :I the blade attack angles;
.` Figures 6A and 6B are detailed views illustrating pivotal ~ movement of the control mechanism to adjust the blade attack .i ~:j 20 angle in response to an increase in wind speed;
Figure 7 is a plan view of rack and pinion connections , between each blade and the control mechanism for automatically ; ~ adjusting the blade attack angles both during rotation about the support column and in response to changes in wind velocity;

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g Figure 8 is a view similar to Figure 7 of the blat~e attack allgles being adjusted by the control. mechanism in re:;ponse to an increase in wind velocity;
Figure 9 is a sectional view taken along the line 9-~ oE Figure 1 of an interconnection between a wind sensor control means actuated by weights to the blade control mechanism to vary the blade attack angles in response to changes in wind velocity;
Figure 9A-9A is a sectional view taken along the lil-~e gR-9~ of Figure 9, illustrating the cross sectional . aiL foil shape of each lower spoke.
- Figure 10 is a perspective view of a control tube col-lllecting the weights in Figure 9 to the offset control mecl,anism;
Figure 11 is a top plan view of a preferred form of wind turbine blade constructed according to the .. invention;
Figure 12 is an end view o~ the blade shown in ~ .
Figure 11, ill~strating the cross-sectional shape of Will~ channeling troughs formed along the entire blade iength;
Figure 12A is a sectional view taken along the line 12~-12~ of Figure 11 of the blade profile oriented : towards the wind flowing through one of the troughs;
! 25 i~'igure 13 is a side plan view of a wind vane according to an aspect of the invention;
E'igure 14 is a top plan view of the wind vane shown in Figure 13; and :: -Figure 15 is an end plan view of the vane shown in 30 -Figilres 13 and 1~. :
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, - : ~ :- ~ , . , . , . -~ strated as includin(3 blade assembly having four, vertically disposed wind driven air foil blades 12a, 12~, 12c and 12d pivotally connected between upper and lower sets of horizontally extending support spokes 14 and 16, respectively, mounted so the blades can turn independently of each other about vertical axis 19 of each blade. Spoke sets 14, 16 are f ixed to upper and lower ends of vertical column 18 rotatably mounted to support base 2~ so that assembly 11 turns about column 18 in response to wind incident on the assembly. Output shaft 22 is coaxially mounted in and connected to be rotatably driven by column 18. Shaft 22 projects below cvlumn 1~, where it is connected to a suitable driven mechanism 24 for converting the torque of shaft 22 to usable power. ~niquely designed blades 12a-12d, described infra, are mounted to spoke sets 14, 16 to rotate about two vertical axes, in particular the blades xotate coaxially with column 18 and about the individual longitudinal axes 19 thereof. Blades 12a-12d are constructed so that wind incident there on is channeled and compressed against each blade for maximum transfer of wind energy to turbine 10. A unique feedback control mcchanism 25 responds to wind velocity (i.e. speed and direction) as detected by a wind vane 26 to diLferentially adjust the angle of attack of blades 12a-12d to maintain approximate constant rotational speed and output power of shaft 22 over a specified range of wind speeds i.e., between minimum and maximum speeds.
(The blade angle of attack is the angle between the :~
; 30 direction of the incident wind on a particular blade and cllord 13, Figuxe 2, of that blade. The blade chord is a vertically extending plant intersecting the longitudinal veL~ically extending blade axls about which each blade .' '; ;' '''- ' . 1,' ' ,"', : . -.' ; , . . .

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turns and a central apex at the intersection of thebla(3e exterior surfaces).
Uerore describing the structure in detail, a gelleral overview of the invention is provided by reference to Figures 1-3 and 7 and 8 wherein wind velocity vector W is assumed to be displaced from blade a.ssembly coordinate axis 21' by angle A2. ~ssembly 11 is rota';ed in the counter clockwise direction about axis 36 in response to velocity vector W. Vertical axes 19 of the upper portions of blades 12a and 12c are respectively displaced counter clockwise and clockwise a~out axis 21' by the angle A2 while axes 19 of the upper portions ot blades 12b and 12d are respectively displaced counter clockwise and clockwise below axis 21' - 15 b~ the angle A2 ~ 90- Because spoke sets 19 and 16 are rotatable independently about axis 36 and the radial ! displacement from axis 36 of intersections 1-4 of axes 19 of blades 12a-12d and spoke set 14 is less than that of the intersections 5-8 of axes 19 of blades 12a-12d wi~h spoke set 16, lower intersections 5-8 lag behind in~ersections 1-4 as assembly 11 rotates about axis 36 so the lower blade portion axes are displaced from axis 21' by angles of A3 and (A3 ~ 90), ~here A2.
Each of blades 12a-12d includes a longitudinal hori~ontal axis 13 that intersects axis 19 and edge 73 (Figure 11) at the intersection of opposite faces of the 70 and 7~' of the blades. As assembly 11 is driven by wind vector W about axis 36 each of blades 12 continuously turns about the axis 19 thereof so that the ancJle oE axis 13 oE each blade continuously changes relati~e to wind vector W i.e., the angle of attack of each blade.
The angles of attack for blades 12 are also a ; ' ., ' ' . , ., ~ .
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function oE the magnitude increases, there is a tendency fOL a greater force to be applied to blades tending to rotate assembly 11 at higher speeds about axis 36. This tendency to overcome to a large degree by changing the angles of attack for blades 12 as they turn about axis 36 so that the surface area of the blades relative to wincl vector W decreases so there is a reduction in the force applied by the wind vector to blade assembly 11, to compensate for the initial tendency of the wind vector to drive assembly 11 at higher speeds~
In the situation illustrated in Figures 2 and 3 it is ass~lmed that velocity vector W has a relatively small ~- magnitude and an angle A2 relative to assembly axis 21' ; ! in the plane of spoke set 14 so that the vector is directed coincident with the axis 21 from axis 36 to axis 19 of blade 12a, and is directed toward the surface oE blade 12 a away from axis 36. [~nder the assumed -~ con(litions, the angles of attack of blades 12a, 12b, 12c and 12d, i.e.t the angles between axes 13 of blades 12a, 12b, 12c and 12d and vector W in Figure 2, in the plane of spoke set 14 are respectively approximately 45j 20, 27, and 2. The angles of attack of blades 12a, 12b, : 12c and 12d in the plane of spoke set 16 lag slightly .` behind l:hose in the plane of spoke set 14 by the same approximate 3 angle. The radial positions of ` inl:ersections 1-~ relative to axis 36 are substantially the same, inside of the radial positions of ~:~ intersections 5-8. At these angles/ maximum force is imparted by wind vector W to assembly 11 because of the 30 large surface area upwind that blade 12a presents to the ` vector, as well as the substantial but smaller areas . presented by advancing blade 12b and downwind blade 12c.
Axis 13 o~ retreating blade 12d, however, is almost .'` " ~ ' ' . ' . : . .- . : , ~ -...... ., .. : .

aligned with vector W, so blade 12d presents a very snlall area to vector W and does not introduce substantial drag.
Now assume that the magnitude of velocity vector W
is substantially larger than previously described and ~ that the angle of the vector is constant. Under these ; cilcumstances, the angles of attack of blades 12a and 12c respectively decrease and increase by relatively ! si~nificant amounts while the angles of attack of blades 12~ and 12d respectively decrease and increase by rclatively insignificant amounts. The angles of attack oE blades 12a-12d in the planes of spoke sets 1~ and 16 cllange together because axes 19 are mounted at fixed radii in spoke sets 14 and 16. The angles oE attack chan~e in the plane of spoke set 14 because wind vane 26 ,~ causes substantial radial shift relative to axis 36 of control rods 66 connected to pivot controllers 201 and 202 for axes 19 of blades 12a and 12c. Because axes 19 are fixed relative to axis 36, the radial shift of rods ; 20 66 drives pivot controllers 201 and 202. The radius of control rods 66 connected to blade 12a and 12c are eEt`ectively decreased and increased respectively; to ` respectively decrease and increase the angle of attack -` of blades 12a and 12c. There is only a slight change in the effective radius of control rods 66 respectively connectod to pivot controllers 203 and 20~ for blades 12b and 12d under the assumed conditions because rods 66 ,~ are at Li911t angles to incident wind vector W. Thereby, the ang,les of attack blades 12b and 12d do not change substantially. The change in the àngle of attack of , upwind blade 12a materially reduces the effective area ~' presented b~ upwind blade 12a to vector W; the change in ~ the angle of attack of downwind blade 12c increases the ., :':

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~lZ~3699`rj dra~J force exerted by blade 12c on assembly 11. The chall~es in the angles o~ blades 12b and 12d do not ncLIllally have a substantial effect on the force imparted by wind vector W on assembly 11. Thus, the tendency for the increased magnitude of wind vector W to turn assembly 11 at high speeds is compensated by the changes in drag angles of blades 12.
- As assembly 11 is turned in response to wind vector W ~he angles of attack of blades 12 are constantly changinq. Thus, as assembly 11 turns 90, t~e angles of attack of blade 12a gradually chan~es from the position illustrated for i~ in Figures 2 and 3 to the position strated in Figures ~ and 3 for blade 12b. As the diLection of wind velocity vector W changes, wind vane 26 controls the angles of blade axes 13 relative to assembly axis 21' so that the blade angles of attack remain constant relative to the direction of wind vector W for the same angular relationship of radius 21 and the wind vector direction. Thus, e.g., for low magnitude wind v~ctors, axis 13 of blade 12a is 45 displaced from radius 21 when radius 21 is aligned with wind vector W.
The mechanism for attaining these results and other improveloents is now described in detail.
Support base 20, as best illustrated in Figure 1, includes a pair of tubular support legs 30 each having a semiciLcular configuration in the vertical plane to elevate blades 12a-12d above the ground or other gellerally horizontal wind impervious surface to obtain maximum exposure of the blades to the wind, while presenting a narrow, rounded wind profile for improved stability. Support legs 30 are orthogonally arranged and fixedly mounted on cylindrical support tube 32 (Fiyure 9), which projects vertically upward from the !
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', ' ' ' ' ' ' ~, , ' ' . ' ' : , ~L2~69 legs and is coaxially mounted in the lower end of hollow cyliildri~al column 18. Column 18 is rotatably supported on ~ube 32 by thrust bearing 34 and yoke 35. Output shaLt 2~ extends coaxially in support tube 32 along ver~ical axis 36 of column 18 and is rotatably supported by axial bearing 38, located in the upper end of the support t~be~ In response to blades 12 rotating, torque is ~ransmitted from rotating column 18 to output sha~t 22 through circular coupling plate 40, horizontally fixed in the column by bolts 42. The upper end of shaft 22 is Eixedly connected to plate 40 in central opening 43 o~ the plate. As illustrated in Figures 1 and 9, low~r spoke set 16 includes four mutually orthogonal, identical hollow spokes 16' extending horizontally and radially from column 18. Each spoke 16' is fixed to the low--r end of column 18 by bolts 44.
Each of spokes 16' is shaped in cross section as an airfoil (Eigure 9~), preferably along the entire length the~eof, to enhance air flow, by p~h ing air upwardly into the interior of blade assembly 11. The air ~oved into the interior of as~embly 11 helps to create a ~cr~a~ in yelQcity: in the assembly interior to enhance the flow of wiad against the blades 12.
Spherical bearing 45, mounted in distal end 46 of each spoke 16', receives the lower end of one oE each of ~lades 12 enablin~ the blades to ~otate about longitudinal axis 19 thereof to change the blades angle of a~tack to that wind force imparted to each blade is maxifni~ed.
Uppcr spoke set 14 also includes fo~r identical hollow spokes 14' extending horizontally radially from col~ n la and spaced 90 from each other. ~ach spoke 14' is Eixed to the upper end of column 18 by L-shaped ': ;

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~)r~ckets 48. ~s illustrated in Figures 2 and 3r corre~ponding pair3 of spoke~ 14', 16' are not vcrtically aligned; instead longitudinal axis 21 of each upper spoke is circumferentially advanced with respect ~o longitudinal axis 21a of each lower spoke so that each blade axis 19 is preferably tilted approximately 3 in the direction of rotation.
~ ach of blades 12a-12d is of identical construction and includes a molded structurel~. strqng - outer skin layer 50 (Figure 11), defining opposite longitudinally extending surfaces 52a and 52b exposed to the wind.
Mass 34 of low density filler, such as expansion Eoam, is disposed between surfaces 52a, 52b to impart structural rigidity to the blades. Rigidity is also ellhanced by shaft 56 extending longitudinally through tlle blade to define blade axis 19.
Upper and lower ends 56a and 56b o~ shaft 56 project outwardly through spoiler end panels 58 respectively located at opposite ends o~ each blade.
Lo~Jer shaft end 56b is received in spherical bearing 45 (l;`igure 9) provided in each lower spoke 16' as mentioned above, ~pper shaft end 56a extends through axial bearing 60 mounted in the bottom and adjacent the outer e;ld of each spoke 14'. Pinion 62 fixed to upper shaft end 5~a is thereby located in each spoke 14' to mesh with a rack 54 attached to free end 66a of connecting rod 66 that extends longitudinally through spoke 14'.
~rhe opposite end 66b of rod 66 is connected to circular connecting plate 68 (Figures 4 and 7) to control adjustment of the angle of attack o~ each blade as assembly 11 rota~es about column 18 as described infra.
a;:ach blade 12a-12b has a teardrop cross section defined by a ~eries of trouqhs 70 and 70' (Figures 11, : ' ., , ~' ' ~
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12, and 12A) respectively formed equispaced and parallel to eac~ other between crests 71' along the entire blade lengl:h on both surfaces 52a and 52b. Mating t:roughs 70, 70' on vyposite surfaces 52a and S2b are longitudinally 5 aligned with each other to intersect trailing edge 72 as a common longitudinal location and are tapered to have decreasing width and depth as they extend from edge 72 to edge 73 in the direction of 73. The taper extends across approximately 80% of the uniform blade width lO bet~een edges 72 and 73. The bottom of each trough 70 and 70' are staggered with respect to each other along the blade length so that each trough defines and airfoil shaped blade segment i.n cross section. In this manner, trc,ughs 70 reduce the speed of wind striking high 15 pr~ssure blade surfaces 52a or 52b, whichever surface is exposed directly to the wind as occurs particularly when the blades are in the upwind position of blade 12a (,urface 52a) or downwind position of blade 12c (surface 52~). 'rhe wind incident on the surface 52a or 52b O divergec; across the entire surface an~ëcelerates as it flows smoothly across the concave surface of each trough towards trailing edge 72, to transfer a greater amount oE ~ind energy to the blades. S imultaneously, in the upwind position of blade 12a, crests 71' located on the 25 low pressure si~e or surface 52b opposite troughs 70 cr.ate a high pressure section opposite the high prcssurc section created by troughs 70 so that the trailing vortex drag of the merging high and low prcssurc sides is substantially reduces, as also arms on 30 the low pressure surface 52a when the blades are in the ; ! downwind position of blade 12c.
When the blades travel into the direct upwind E-osition of blade 12d in Figure 2, trough 70' on high -. .

: . .

' -. ~ . , .: :

3L2~699~

prossuro surface 52b primarily coact with tro~ghs 70 onlow pressure surface 52a to reduce vortex drag since the blades in this position are generally aligned with the wil~d. When the blades are in the position of blade 12b in FiguLe 2, the troughs 70 on hiyh pressure surfa~e 52a naLrow in the downwind direction, causing wind to colllpress and accelerate against tlle downwind leading edge 73 of the blade to rotate the blade in the dire~tion oE rotation.
To minimize the total surface area of troughs 70 and crests 71 (defined by ~roughs 70') directly cha~ elillg wind flow across the width of ea~h blade 12a-12d and ~hereby minimize skin friction, the preferred rallge oE the ratio of width W to depth D of each trough 1, is approximately 4:1 to 8:1. For optimal results, however, a preferred ratio W:D is abut 6:1.
As best illustrated in Figure 1 for blades 12a and l~c, blades 12a-12d are mounted on spokes 14' and 16' so the upper portion of each blade is closer to column 18 than the lower portion of the blade wherein blade assembly 11 is similar to a truncated cone having a lower base layer than an upper base. Because of this truncated cone arrangement, the pair of downwind blades draws air into the interior of blade assembly 11 through the upper section of the assembly. The air drawn into the upper part of assembly 18 spirals downwardly about column 18 to combine with air Elowing upwardly into the assembly through air foil shaped spokes 16'. The upwardly and do~-nwardly directed air currents meet in ~he intericr of assembly 11 where they combine to exit ~r~m approximately the lower two thirds of the assembly (l.e., in the space between spokes 16' and two thirds of - the way up to spokes lg'). The exiting air current .' : , ` ' . , ~ . . - ~ ;

~2~699~;

fl-ws in the same general direction as the incident ~ind. With this arrangement, a large volute volume of air is swirled and accelerated in less than the total interior volume (i.e.., the lower two thirds portion) of assembly 11, th~reby imparting additional wind energy to b]ades 12a-12d. The accelerated, swirliny air flow obtained with inclined blades 12a-12d also promotes lalninar flow conditions in the interior of assembly 11 without creatiny a standing wave effect (i.e. wind repeatedly reflecting off the blades in the assembly interior, without escaping from the interior; the `~ standiny wave tends to cause turbulence and impair blade eEficiency).
o obtain the accelerated swirling air flow in asiembly 11 as described above, the ratio of the diameter of upper spoke set 14 to the diameter of lower sp(jke set 16 is preferably about 2:3 althouyh the ratio c.-ln vary from between appro~imately 1:2 to 4:5; the he~i(3ht of column 18 is preferably equal to the sum of the diameters of upper and lower spoke sets 14, 16 but can be as small as the diameter oE the lower spoke set.
i';h the aforesaid preferred ratios, blades 12a-12d are positioned on spokes 19', 16' so axis 19 of each blade is inclined from the vertical towards central axis 36 by about 6 (inclination angle Al, Fiyure 9); while being advanced about 3 (blade advance angle A2) in the difection of rotation, as discussed above. ~lowever, wh~ll the ratio of diameters of the upper and lower sl)okes 1~' and 16' as well as the height of column 18, is varied within the above ranges, I have found that the followiny equations can be used to calculate inclination angles Al and blade advance angle A2, in degrees, to within a 1 accuracy:

;'~ .
,, . - :
-1~ ~6~95 o B-T
1 2~l [ ( I )~

where: H = height of column 18 B = diameter of lower spoke set 16 T = diameter of upper spoke set 14 Sillce blade axis 19 is tilted preferably about 3 in the direction of blade rotation and preerably 6 towards axis 36 as mentioned above, it can be seen from Fi~Jures 2 and 3 that the angle of attack of each blade 12a-12d to the wind increases as the height of each blade increases toward upper spoke set 14 (i.e., B>B' in Figure 2 and 3). This variation in blade attack angle is necessary due to the lower tangential velocity ! of smaller upper spokes 14' relative to the lower spokes 16' during rotation of assembly 11 about column 18. In this manner, each section along the entire length of blades 12a-12d is respectively maintained at a favorable an~le or attack between B and B' to optimize blade efliciencyL Furthermore, to produce maximum torque with turbine 10, I have found that the following formula can be used to calculate the width (W) of each blade 12a-12d:
W = 0.0533~B

Os~illation of each blade 12a-12d about blade axis 19 thereof is controlled by a rack and pinion assembly comprised of rack 64 pivotally supported in the upper spokes on pillow blocks 65 or slider wheel 65' at outer ;' ,. .

~2~9g~

~n~, G5a of each connecting rod 66; racks 64 respectively me llwi~:h pinions 62 provided at upper end 56a'of each blade. ~s illustrated in Figures 4 and 7, three of col-lnecting rods 66 are pivot:ally mounted to circular conllecting plate 68, located in the upper portion of column 18, by spherical bearings 75 peripherally disposed on the plate 90 from each other. The inner end of the remaining connectiny rod 66', secured to blade 12a, is fixedly attached to the periphery oE plate 6~ at a location 90 from adjacent bearing 75. Thereby rod~ 65 are free to pivot about fixed points adjacent tl;-~ periphery plate 68 while rod 66' always remains fii:ed in position so the longitudinal axis thereof inl,ersecls axis 36.
`~ ~, 15 Spherical bearing 77, mounted in the center of plate 6a, receive~ an upper vertical section 100 of a control shaft 80 that projects through upper end 82 of `-` column 18, covered by a flexible weather seal 84. Wind `, vane 2h, fixed to the upper end of shaft 80 above upper `- 20 sp~ke set 14, adjusts the pitch of blades 12a-12d th~vugh the asseinblies including racks 64 and pinions 62 in response to changes in wind velocity, as described below. 5top 8G, fixed to shaft section 100 supports bearing 77 and thereby plate 68 in a horizontal plane immediately below connecting rods 66.
Win-J vane 26, as best illustrated in Figures 13-15, - is a horizontally extending structure having a low, relatively thick counterweight profiled forward segment ~;~ 88 and a thin relatively high rearward segment 90.
30 Segment3 88, 90 located on opposite sides of upper see~ion 100 of control shaft 80 (Figure 4), have the same weight for ilnproved stability. Fixed to vertical ~ac~92 oC rear segment 90 is air scoop 94 having curved ; , ' . ' .

, ' .~ .
, ~ .

3699~;

wall 95 defining large upwind opening 96 and a smaller do~nwind opening 97. As wind passes around profiled foLward segmellt 88 and enters upwind opening 96, wall 95 tapered towards rear opening 97, causes the passing wind ~- 5 ~o strike vertical face 92, to turn vane 26 into ~- alignment with the wind and rotate control assembly 80.
Control assembly 80, Eorming wind speed and ; di~ection detector of feedback control mechanism 25, collsti~utes an important feature o~ the invention. ~s - lO illustrated in Figure 4, assembly ~0 includes shaft 81 tl~at is located primarily in column 18 and has straight vertically extending upper and intermediate segments 100 and 0].8 connected to each other by inclined segment 104.
~puer section 100 extends upwardly through center b~aring 77 so it supports vane 26 above blade assembly . Rod 81 includes portion 106, projecting downwardly 1rom and inclined relative to segment 108. Shaft por~ions 100, 104, 106, and 108 are coplanar, with veL~ical portion 108 radially offset (i.e., non-coaxial) with respect to section 100. Sleeve 110, fixed to o.Eset shaft portion 108, includes an elongated horizontal passage 112 containing horizontal pin 114, haviny one end attached to an inner surface of sleeve bearing 115. Bearing 115 is coaxial with axis 36 and is rol:atably mounte~ in the upper portion of column 18 by pairs of upper and lower axially spaced bearings 117 - .
located between the facing outer walls of bearing sleeve ~; 115 and inner surfaces o~ column 18. Vertically e;~tending seats 119 and 122, respectively at the lower ellds oE inclined shaft por-tion 106 and sleeve 115 cap~ure opposi~e ends of compression spring 120, having a horizontal axis to provide a counter force for the ~endency o~ shaft 81 to rock about pin 114 in response -~
' ':
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.
. . - ' :

~2~69g~

to vane 26 tilting as a function of the speed of wind incident on the vane. When the wind calms, spring 120 stabilizes vane 26 in the horizontal plane. The pivot angle of rod 81 relative to pin 114 controls radial displacement on control plate 68 relative to axis 36 of column 18, to control the angular position of each blade 12a-12d about the axis thereof at the different angles about axis 36.
To understand the operation assume that each blade 12a-12d is mounted to assume a particular angle of attack relative to the incident wind (see Figure 7) which is aligned with the axis of spoke 16 carrying blade 12a. Thereby blades 12a and 12c are - respectively in upwind and downwind positions, while blades 12b and 12d are in cross wind positions. Blade 12a is rotated by connecting rod 6, rack 64 and pinion 62 connected to it so it has a favourable wind angle of attack, depending upon wind speed, of approximately 45, the approximate angle where maximum wind energy ` 20 is imparted to rotate the blades. As blade 12a rotates 90 about column axis 36 into the downwind position occupied by blade 12b in Figure 7, the effective wind striking exposed klade surface 52a : causes pinion 62 to rotate in meshing engagement with ` 25 the teeth of rack 64 (pivotally supported within each spoke 14l by a pillow block 65 or grooved control wheel 65') so that blade 12a rotates about axis 19 in a controlled manner to assume a lesser angle of attack of about 20 allowing the blade to continue imparting rotative torque to the -` turbine structure without causing excessive wind resistance. As blade 12a continue~ travelling downwind into the position occupied by blade 12c in ; Figure 7, pinion 62 continues to rotate while moving rack 64 so that the blade assumes . :

.
:
. ~ .

;

( an an(31e oE attack of about 27 allowiny wind to slllo~ ly exit from the interior oE turbine 10. ~s blade l~a then rotates in the upwind direction into the J~o;i~iOn of blade 12d in Figure 7, the angle of attack bccomes about 2 so that the blade is virtually tr~veling parallel to the wind to minimize resistance.
ilnultalleously, of course, connecting rods 66 which are in,~rc~ ected through plate 68 move radially to adjust ~- the blacle angle positions of the other blades 12b-12c 0 d~lL ing travel thereof into the aEoresaid positions.
OfEset shaft portions 104, 106 and 108 oE control shaEt 81, being pivotal in vertical plane 125 about pin ; 11~, advantageously allow radial placement of upper sh.ft portion 100 and thereby control plate 68 so that ~he eEEective length of each connecting rod 66 col--s.antly changes during blade rotation about central a~is 36 due to the aforesaid movement of racks 64 caused b~ pinions 62. By experimentation, it has been found tha~ ofEset portions 104, 106 and 108 are mounted so as to be oEEset from the forward or upwind segment 88 of valle 26 in the direction of rotation by an angle 0 of between 30 and 40, preferably 35. It has been dls~overed that this mounting relationship uniquely op~Lates to create a favorable attack angle of blades 12a-I2d for a longer duration during the downwind phase c~f bla-le travel, enabling turbine 10 to derive more uo~er Erom this phase of rotation about axis 36. This arrangement also ~ermits blades 12a-12d to rotate about ~; column 18 at a tangential linear velocity of between 2.3 an-i 2.6 ~imes greater than wind speed to obtain maximum .. . .
power output.
~ earings 75, 77 maintain connecting plate 68 in sul/stall~ially the same horizo4tal plane as the ~.
:

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.. ..

~ . . . .

- l~r~ s --2~--loll;Ji-udinal axis oE connecting rods 66 continuously change in the aforesaid manner as the blade attack an~les change in the aforesaid manner duriny rotation about axis 36. Furthermore, bearings 75, 77 as well as tlle aforesaid rack and pinion connections and easy pivotiny movement obtained with the offset control shaft ~0 within cylindrical bearin~ 115 provide low friction, smooth translational movement of connecting rods 66.
Wind vane 26 uniquely operates as a static wind load control through the aEoresaid rack and pinion c~nllections 201-204 and control sha~t 80 to provide further blade adjusl:ment in response to changes in wind sp~ ed or direction. For example, should wind direction change ~rom W to W' in Figure 8, rotation of vane 26 in~o realignment with the wind causes corresponding rotatioll of shaft section 100 and thereby pivotal -~ Inovement oE ofEset portion 108 so that plate 68 moves radially to reorient the blade angles. Vane 26 rocks ba~:l;ward about pin 114 in response to an inc~eased wind low entering air scoop 94, (see Figures 6A and 6s)~
causing plate 68 to translate in the downwind direction by the action oE shaft section 100 acting against the ylate. Connecting rods 66 between plate 68 and blades 12a-12d are transIated causing the effective radii of inl:crsections 1-4 and the attack angles oE blades 12a-; lZd to change, as described supra, so that the blades do nul: oveLspeed. Thus constant speed and power output oE --bl~l:les 12a-12d are maintained while excessive stress and possibie damage to turbine 10 is avoided.
Sl~ould excessive wind conditions develop (e.g., }:urricane wînd Eorce), racks 69 and pinions 62 respond t control shaft 80 to adjust the blade attack angles to ~` turn l~lades 12a-12d so axes 13 are aligned with wind ~, .

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.
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. . . .: ., , ~ -. . . . ...

~2 ~69 ve~ocity vector W to stop turbine 10. The aEoresaid arLangelllcnt also adjusts the blade angles of attack when assembly 11 has been braked, to dump hiyh wind loads Lrom blades 12a-12d, thereby avoiding damage to the ~` 5 blade s~ructures.
A second embodiment oE control mechanism 25 for contl:olling the blade angles of attack in response to `~ challges in wind speed and direction includes a pair of cylindrical weights 120 resp~ectively located inside of two diametrically opposed lower spokes 16'. ~s ; i]]ustr.lted in Figure 9, each cylindrical weight 120 is sli~ably mounted between pairs of upper and lower roller bcarings 122 and 124, respectively carried in sclnicylindrical channels 126 of bearing support members 15 12-1 and 127a. Roller bearings 122, 124 engage circumEerential surfaces of weights 120 to define a horizontal slide path to enable the weights to move raclially with respect to column 18 through spokes 16' in response to variations in centrific force caused by changes in wind velocity acting on blades 12a-12d.
T~lo cables 128, respectively attached to the faces `~ oE weiyhts 120 adjacent column I8, pass around pulleys ~ 130, mounted on yoke 35 and extend vertically upward .~ .
bet~een column 18 and support shaft 32, for attachment to a pair of vertically extending connecting rods 132.
- r~Ods 132 are sli~ably disposed in apertures 134 of coupling plate 40; upper ends of the rods are connected to hori~ontal cross plate 136, located above the coupling plate. Connecting rod 137, fixed to the center 30 oE plate 136, extends upwardly along central axis 36.
5he upper end of rod 137 passes through opening 138 in pla~e 139 at the bottom o hollow, square control tube 14~ and is connectcd to throwout bearing 142, mounted on ~ I
:`~
; ' :-' ' ' ~

, .~ . , . ~, ;.

~28~995 plite 139. Bearing 142 prevents rotation oE control tu!e 140 with rod 137 and weights 120 about the column 36 aY~is during blade rotation about column 18. Flexible oil ~ube 141 extends through shaft 22 to supply lu~ricant from a source (not shown) to bearing 142.
Tube 140 is mounted directly below and coaxially wi~ll cylindrical bearing 115 ~surrounding oEfset shaft po;~ion 108) to receive the lower inclined shaft portion 106 between side walls 144. Tube 140 includes side ~ialls 144 one oE which has an opening 145 through which thc lower end 118 of shaEt portion 106 projects. Roller ~-14~, ro~atably mounted to upper edge 148 of opening 145, - ~rolls orl straight upper inclined surface 150 of shaft :.............. pOL~iOn 106 to vary the position o~ offset portion 108 in the manner described below. Upper end 153 of L~
llaped guide member 152 is fixed to the inner surface of cyllnder 115 to extend downwardly to be received between and slide along side walls 144 to maintain square tube 14~d in vertical, coaxial alignment with the cylinder.
~;;20 Pin 114 is fixed to the upper portion o~ guide member 152. Compression spring 12~ is horizontally disposed in tul,c 14~ between lower end 118 of inclined portion 106 an-l sea. 122', abutting against the lower edye on the inner surface of the guide member.
Wi~h the arrangement of Figure 9, weights 120 slide radially in spokes 16, so the weights move away from column 18 when the wind speed acting on blades 12a-12d in-~reases. The outward movement oE weights 120 draws cablcs 128 down to exert a downward force on connecting ! 30 ro~ 137 throughlrod 132 and cross plate 136 to pull ;~ s~ are tube 140 (which does not rotate with connecting rocl 139 ~y virtue oE throwout bearing 132). ~s tube 140 moves dvwn, roller 146 exerts a force on inclined -.' . ,- . .; ' ~
,.... .

~:13qEig9~

surface 150 so that offset shaft portion 108 pivots on pin 114 to increase the attack angles of blades 12a-12d in the manner described above. Spring 155, connecting plate 136 to coupling plate 40, is thereby loaded in compression so that weights 120 are retracted by the force of spring 155 when wind speed decreases, allowing square tube 140 and roller 146 to move up along surface 150 to restore the blade angles.
Weights 120 in the second embodiment are preferred for use instead of wind vane 26 in large installations. However, weights 120 can be used in - combination with vane 26 to vary the blade attack angles in the aforesaid manner. When using weights -; 120, it will be recognized that they tend to move radially back and forth about an equilibrium point -~ within spokes 16' as the weights adjust the blade angles of attack in response to changes in wind speed and direction, since, after initial adjustment occurs ` in the aforesaid manner, the weights tend to move -~ 20 radially inward (if wind speed has increased or wind direction has changed counterclockwise in Figure 2) in ~` response to a lowering of centrifugal force acting on `~ the blades ~restored to constant velocity movement).

:-~ ' '.

', ' " ''

Claims (14)

1. A wind driven turbine of the vertical-axis-type com-prising: (a) a support base; (b) a generally-vertical column rotatably mounted to the support base; (c) upper and lower sup-port means respectively mounted on said column for rotation therewith; (d) a plurality of wind driven blades connected between the upper and lower support means for rotation about said column, each blade being individually rotatable about a blade axis extending longitudinally through the blade to vary a blade angle of attack thereof relative to wind velocity during rotation about the column; and (e) control means for variably adjusting angles of attack of each blade to incident wind, said control means including a connecting rod means having a drive means for rotating each blade about the associated blade axis in response to radial movement of the connecting rod means and control shaft pivotally mounted within said column and having a first shaft portion connected to the connecting rod means and a second shaft portion radially offset from the first shaft portion and pivo-tally connected, radially to displace the first portion and thereby the connecting rod means to vary the blade angles of attack during rotation about said column; wherein said upper support means includes four substantially-identical spokes, each extending substantially-horizontally radially from said column, said connecting rod means including a connecting rod extending through each upper spoke for connection of said drive means to a .29.

driven means mounted on a portion of a shaft passing through each blade; wherein said control means further includes a plate to which three of said connecting rods are pivotally affixed by spherical bearing means respectively spaced 90° from each other, and a center spherical bearing mounted in said plate to receive the first shaft portion therein, said fourth connecting rod being non-rotatably affixed to the periphery of said plate, enabling radial displacement of said plate and connecting rods in a generally-horizontal plane; wherein said control means further includes a cylindrical bearing member rotatably mounted within said column on races, with said offset second shaft portion being pivotally mounted within said cylindrical bearing by means of a pivot pin affixed to an inner surface of said bearing mounted cylinder.

2. The turbine of claim 1, further including a compression spring extending under said pivot pin on a second shaft portion, to contact said inner cylinder to bias said offset portion.

3. The turbine of claim 2, wherein said linearity-driven blade means includes a rack affixed to an outer end of each eon-necting rod, said driven means including a pinion meshing with teeth provided on each rack to cause radial displacement of said connecting rods through the alignment plate.

4. The turbine of claim 3, further including a wind vane structure affixed to said first shaft portion above said upper spokes, said vane causing rotational movement of said control shaft in response to variations in wind direction, with wind velocity thereby causing pivotal are movement of said second .30.

shaft portion and radial displacement of each connecting rod through said control plate, radially to displace each rack to change the blade attack angles.

5. The turbine of claim 4, wherein said wind vane includes:
a low, relatively-thick, counterweigh-t in a forward segment and a thin, relatively-high, rearward segment extending horizontally from said first shaft portion; and an air scoop located on a vertical face of said rear segment, said air scoop having a curved wall defining a large upwind opening and a smaller down-wind opening enabling wind to enter said air scoop to strike the vertical face and thereby to rotate said vane into the wind, thereby controlling the feedback response.

6. The turbine of claim 5, wherein said lower support means includes four identical spokes, each extending horizontally and radially from its respective attachment to said column and spaced 90° from each other.

7. The turbine of claim 6, further including: a pair of weights respectively mounted within an interior area of two diametrically-opposed lower spokes on roller bearing means enabl-ing said weights to move radially with respect to said column through said spokes in response to variations in centrifugal force caused by changes in wind velocity acting upon said blades;
and means interconnecting each weight to pivot said offset second shaft portion to adjust the blade angles in response to movement of said weights.

.31-

8. The turbine of claim 7, wherein said interconnecting means includes cable means attached to each weight and extending upwardly through the column for the connection to a hollow tubu-lar member located in vertical, coaxial alignment with said cylinder to receive a lower inclined portion of said second shaft portion through an opening formed in a side wall of said tubular member, said opening carrying a roller rotatably mounted to an upper edge of the opening to engage an inclined surface of the inclined rod portion, said tubular member being vertically-mov-able in response to radial displacement of said weights, causing said roller to travel along the inclined surface, thereby to pivot said offset portion, causing blade adjustment.

9. The turbine of claim 8 further including an output shaft interconnected to, and coaxially-bearing-mounted within, said column support for rotational movement therewith, said output shaft projecting downwardly from within said supporting column tube to deliver rotative torque to a means converting torque to usable power.

10. The turbine of claim 6 wherein a ratio of the length of the upper spoke to the length of the lower spoke is approximately 2:3 and the height of said column is equal approximately to the sum of the diameters of said upper and lower spoke sets, causing each blade to be upwardly inclined towards the central vertical axis of said column by a blade inclination angle of approximately 6° as measured between a vertical plane extending tangentially through an outer end of said lower spoke and said blade axis, said blades thereby causing air entering the interior of said turbine from an upper section thereof to rotate downward about said column to produce a swirling accelerated air flow imparting additional wind energy to said blades.

11. The turbine of claim 10, wherein each lower spoke is airfoil-shaped, causing wind to flow upwardly into the interior of said turbine through said spokes, to flow with the accelerated swirling air flow obtained with said inclined blades for improved efficiency.

12. The turbine of claim 11, wherein said upper spokes are mounted to said column so as to be circumferentially advanced with respect to the lower spokes by approximately 3° incline angle divided by two, thereby to obtain a higher angle of attack at the upper blade portions relative to the angle of attack of the lower blade portions.

13. The turbine of claim 6, wherein a ratio of the diameter of the upper spoke set relative to the lower spoke set is approx-imately 1:2 to 4:5.

14. The turbine of claim 13, wherein the height of said column is at least approximately equal to the diameter of the lower spoke set up to and including the sum of the diameters of the upper and lower spoke sets.

.33.