CA1229796A

CA1229796A - Windmill

Info

Publication number: CA1229796A
Application number: CA000447299A
Authority: CA
Inventors: Gilles Ouellet
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-02-13
Filing date: 1984-02-13
Publication date: 1987-12-01

Abstract

ABSTRACT OF THE DISCLOSURE:
A windmill of the type having a rotor rotatable about a vertical axis, and a wind deflector rotatably mounted relative to the rotor about the same vertical axis to be able to position a wall between a portion of the rotor and the wind. This wall is advantageously shaped in a manner to create a reduced pressure behind it to make the rotor more efficient. A driving system is provided for automatically rotatably positioning the wind deflector to maximize the wind effect on the rotor. This system can be override for auto-rotatably positioning the deflector back in such a position as to reduce the wind effect on the rotor as the wind speed increases above a predetermined speed.

Description

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The present invention relates to an improved wind-mill of the type comprising a rotor rotatable about a vertical axis.
Windmills of the above-mentioned type are already known. These windmills usually have a shroud or wind deElector on the outside of the rotor. The wind deflector is rotatable relative to the rotor~about the same vertical axis and can be moved to position a wall in front of a portion of the rotor to block wind from reaching that portion of the rotor. The remaining uncovered portion of the rotor on one side of the vertical axis is pushed by the wind and causes the rotor to rotate about ~ts axis and thus to produce power. Generally, the wind deflector is also equipped with a vane positioned to be acted on by the wind in a manner to automatically rotate the wind deflector to an optimum position relative to the wind direction on the rotor. United ~tates Patent nos 1,502,950 of 1924; 3,970,409 of 1976 and 4,031,405 of 1977 are illustrative of such windmills.
An object of the present invention is to provide a windmill of the type comprising a rotor rotatable about a vertical axis, which advantageously distinguishes over the known windmills in that it incorporates a new kind of wind deflector that improves the efficiency of the rotor. This new kind of wind deflector comprises a first wall that blocks a portion of the wind to the rotor.
This first wall is shaped to deflect the wind about the rotor in such a manner as to create a reduced pressure behind the wall. This feature already improves rotor efficiency. The wind deflector may also comprise a second wall spaced from the first wall, which second wall is shaped to direct wind on the rotor to further increase its efficiency.
Mostofthe known windmills have no means for 7~36 for automatically changing the positlon of the wind deflec-tor. If the wind blows too hard, it can damage the rotor before the deflector is manually adjus-ted to block off the wind. ThUS i-t is important to be able to automa-tically change the position of the deflector to block off more of -the rotor to protect it as the velocity of the wind increases.
Another object of the present invention is to pro-vide a windmill of the above-mentioned type, with means for automatically positioning the deflector in a protective position relative to the rotor if the wind speed increases to a point where it might damage the rotor.
In one embodiment of the invention, drive means are provided for rotating the deflector relative to the rotor. These drive means are controlled by a pair of motor controllers connected to a weather vane and an anemometer. The weather vane, through its controller, positions the deflector in an optimum position relative to the wind direction to get the best rotor efficiency.
The anemometer, through its controller, positions the deflector to shut off more wind to the rotor if the wind speed picks up. Thus the rotor, and any other windmill parts, are protected from possible damage due to high winds.
In another embodiment of the invention, the same resul-ts are achieved using a first wind vane to directly position the deflector in an optimum position, and a second wind vane to directly rotate the deflector to a position shutting off more wind to the rotor if the wind speed increases. The second vane is arranged to override the first vane as the wind speed picks up.
The invention is particularly directed toward an improved windmill of the type comprising a horizontal platform provided with a fixed, vertical central post~

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a rotor provided with a plurality of vertical vanes, this rotor being rotatably mounted about the post on the plat-form; a wind deflector rotatably mounted relative to the rotor about the post on the platform; and means Eor rota-tably positloning the deflec-tor relative to the rotor and to the wind direction, to maximize the wind effect on the rotor. In accordance with the invention, this windwill is improved in that its deflector includes a first wall sized to shield at least half of the rotor from the wind and shaped to create a reduced pressure behind the wall to assist the rotor in rotating more efficiently.
In accordance with a preferred embodiment of the invention, the first wall has an airfoil cross-sectional shape defining a leading edge and a trailing edge. The trailing edge extends in a direction parallel to the axis of rotation of the rotor and lies adjacent an imaginary vertical cylinder generated by the rotation of the outer-most portions of the vane of the rotor, the first wall thus extending tangentially from thisimaginary cylinder to shield at least half the rotor from the wind.
In accordance with another preferred embodiment of the invention, the wind deflector includes a second wall having its vertical center located at about 90 around the imaginary cylinder of rotation from the trailing edge of the first wall in the direction of the rotor.
In accordance with further preferred embodiment of the invention, means may be provided for overriding the first means and rotatably positioning the deflector to reduce the wind effect on the rotor as the wind speed increase above a predetermined speed.
The invention and its numerous advantages will be better understood with reference to the following non-restrictive description of two embodiments thereof, taken in connection with the accompanying drawings in which:

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Fig. 1 is a front view of a windmill according to the invention;
Fig. 2 is a detail, vertical cross-section view of another windmill according to the invention;
Fig. 3 appearingon-the same sheet of drawing as Fig. 1 is a -top view of -the windmill shown in Fig. 2;
Figs. 4A and 4s are horizontal cross-section views of the rotor and the wind deflector of the windmills shown in Figs.l to 3;
Fig 5 is a perspective view of the windmill shown in Fig. l; and Fig. 6 is a top view of the windmill shown in Figs 1 and 5.
The windmill 1 of the present invention, as shown in Figs. 1 and 2, comprises a horizontal platform 3 mounted on top of a tower 5. A mounting post 7 extends vertically up from the center of the platform 3.
A rotor 9 is rotatably mounted on the platform 3 about the post 7 as shown in Figs. 3. The rotor 9 has vertical vanes 11 extending between a circular, horizontal bottom plate 13, and a circular top plate 15 which is parallel to the bottom plate 13. The bottom plate 13 has a central opening 17 through which the post 7 passes.
A bearing 19 mounts the bottom plate 13 for rotation both on the platform 3 and about the post 7. The top plate 15 also has a central opening 21 through which the post 7 passes. A bearing 23 in the opening 21 rotatably mounts the top plate 15 about the post 7.
At least three vertical vanes 11 are fixedly mounted between the bottom and top plates 13 and 15.
These vanes 11 are equally spaced about the post 7 and equally spaced outwardly from the post 7 as shown in Figs.
4A and 4B. The outer edge 25 of each vane 11 preferably lies in a plane joining the outer edges 27 and 29 of the ~L2297~3~

plates 13 and 15 respectively as shown in Fig 3. Each vane 11 preferably has a semi-cylindrical shape as shown in Fig. 4.
A wind deflector 31 is mounted about the rotor 9 as shown in Figs. 2 and 4. This wind deflector 31 is rotatably mounted on the platform 3 about the post 7 and comprises a bottom, horizontal ring 33 encircling the bottom plate 13 of the rotor 9 just abor the pl~tform 3. A top ho~rizontal ring 35, with a circular cover 37, is located just above the top plate 15 of the rotor. A
first vertical wall 39, a second vertical wall 41, and a column 43, generally equally spaced about the post 7, join the bottom and top rings 33 and 35 together in a rigid structure. A central opening 45 is provided in the cover 37 of the deflector 31. A bearing 47 in the opening 45 rotatably mounts the deflector 31 about the post 7. the deflector 31 is also rotatably mounted on a circular track 49 on the platform 3. The track 49 is angled inwardly and casters or rollers 51 on the bottom of bottom ring 33, which angle outwardly, ride on the track 49 to rotatably mount the wind deflector 31 on -the platform 3 about the rotor 9. The outwardly angled rollers 51 not only rotatably mount the deflector 31 on the platform 3 but also keep it centered about the post 7.
The first vertical wall 39 on the wind deflector 31 is sized to shield half of the rotor 9 from the wind as shown in Figs. 4A and 4B. In accordance with the present invention, this first vertical wall 39 is also shaped to create a reduced pressure behind it which makes the rotor 9 rotate more efficiently.
The first wall 39 has an airfoil cross-sectional shape as seen in Fig. 4, to create the reduced pressure and is positioned to have its trailing edge 55 adjacent the imaginary cylinder 57 generated by the edges 25 of the vanes 11 during rotation of the rotor 9. The 1,2~9~

trailing edge 55 ls also parallel to the axis of rotation 59 of the rotor 9. The wall 39 extends generally tangen-tially from the imaginary cylinder 57 with its leading edge 61 extending just past an imaginary straight plane 63 parallel to the wind direction and which plane 63 is just touched by the rotating edges 25 and the vanes 11.
When it stands in the proper position, the first wall 39 is generally perpendicular to the wind direction.
The wall 39 splits the flow of wind hitting it into a first branch 65 that flows in the direction of movement of the vanes emerging past the trailing edge 55 of the wall 39 to assist the vanes 11, and into a second branch 67 that flows around the leading edge 61 past the rotor 9. As the second branch 67 flows over the leading airfoil surface 69 of the wall and around its leading edge 61, it creates a low pressure region 71 behind it adjacent its trailing surface 73 which makes the rotation of the rotor 9 more efficient.
The second vertical wall 41 is relatively narrow and has its vertical center located about 90 from the trailing edge of the first wall 39 in the direction of rotation of the rotor 9, as shown in Fig. 4. The second wall 41 cooperates with the top and bottom of plates 13 and 15 to channel the wind into the vanes 11. The wall 41 can be straight extending tangential to the imaginary cyiinder 57. Preferably however, as shown in Fig. 4, the second wall 41 has a convex surface 75 about a vertical axis when viewed from the axis of rotation 59.
Thus the wall 41 " squeezes" the wind passing over its concave surface 75 into the vanes 11 as they pass the wall 41 to make the rotor 9 more efficient.
The column 43 can comprise a rod fastened at its ends to both rings 33 and 35 and located generally equidistant from walls 39 and 41.

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Means are provided for aut~matically, rotatably positioning the wind deflector 31 relative to the rotor 9 so that the first wall 39 is in an optimum position to block wind from reaching one side oE the rotor 9 no matter which direction the wind is blowing from.
In one embodiment of the invention as shown in Figs, 2 and 3, these positioning means can comprise a gear ring 81 moun-ted on the upper surface 83 of the bot-tom ring 33. A drive motor 85 having a drive gear 87 projecting therefrom is mounted on the platform 3 adjacent bottom ring 33. The drive gear 87 cooperates with the gear ring 81 on the deflector 31 to rotate the deflector 31 in either direction depending on the rota-tion of the drive gear 87 by motor 85.
Automatic control means are provided for operating motor 85 to properly position wind deflector 31 relative to the wind direction. As shown in Fig. 2 a weather vane 89 is employed to sense the wind direction. The position of the weather vane 89 operates a motor control 91 which drives the motor 85 to position the deflector 31 with the wall 39 in the optimum position relative to rotor 9, having regard to the wind direction.
In the optimum position, as shown in Figs, 4A and 4B, the first wall 39 blocks off about one-half of the rotor 9 from the wind. The half of the rotor blocked off, is that side which rotates toward the wind. The side of the rotor 9 open to the wind catches the wind in the trough-shaped vanes 11 causing rotation of the rotor 9.
The second wall 41 at this time is positioned generally parallel with the wind direction as shown in Figs. 4A and 4B, and serves to direct the wind onto the vanes while reducing turbulence as each vane 11 passes by the second wall 41 in itsmostopen position to the wind.
The rotation of the rotor can be transformed into 9~

electrical power using a generator 95 mounted on the tower 5 just beneath platform 3 as shown in Fig. 2. A ring gear 97 is mounted on -the bottom plate 13 of the rotor 9.
A driven gear 99 is carried on the shaft 101 of the generator 95. The driven gear 99 is driven by the ring gear 97, as the rotor 9 rotates, to ~rive the generator 95.
Means may also be provided for automatically positioning the wind deflector 31 in a position to cu-t off more oE the wind reaching the rotor 9 if the wind velocity is too high. This is to prevent damage to the rotor 9. These means can include an anemometer 105 for measuring wind speed. The anemometer 105 is connected to a motor control 107. If the wind speed reaches a dangerous level, the motor control 107 is actuated by anemometer 105 to move the wind deflector 31 via motor 85 to a position where the first wall 39 blocks off the wind to more of the rotor 9. Motor control 107 overrides motor control 91. Once the wind speed reduces, motor control 91 takes over again moving deflector 31 to its optimum position. A manual motor control 109 can also be provided for overriding the other two controls 91 and 107.
In anobher embodiment of the invention as shown in Figs. 1, 5 and 6, the means for automatically positioning the deflector 31 in an optimum position can comprise a vane 111 rotatably mounted by tubular collar 113 at one end to the top of the post 7 above the deflector 31. The vane 111 replaces the ring gear 81 and motor 85 used to rotate the deflector 31 from the motor controls 91l 107 and 109. A stop pin 115 projects up from cover 37 of the deflector 31 near its outer edge.
The stop pin 115 is loca-ted approximately on a diametri-cal line passing through the trailing edge 55 of the first wall 39 on the deflector 31 and the center of post 7.
A tension spring 117 is connected at one end to a mounting 979~
pin 119 mounted on the cover 37 and at its other end to the vane 111 near its outer end 121. The mounting pin 119 on the cover 37 is located near the outer edge of the cover and about 75 away from the stop pin 115 S toward the first wall 39 on the deflector 31. The spring 117 normally biases the vane 111 against the stop pin 115 to lock it in position relative to the deflector 31. The wind moves the vane 111 into a position parallel with the wind direction, and the vane movement will auto-matically move the deflector 31 to position it in an optimum position relative to the rotor 9.
Means are provided, associated with the vane 111, for automatically repositioning the deflector 31 to protect the rotor 9 if the wind velocity gets dangerously high. These means include a second vane 125 mounted above the first vane 111 and extending transverse to it.
A pair of arms 127 extends down from the second vane 125 to straddle the first vane 111. A pin 129 pivotably connects the arms 127 to the first vane 111 adjacent its top edge 131. A pulley 133 is mounted on the side of the first vane 111, opposite the side bearing against the stop pin 115, with a bracket 135 located adjacent the outer edge 121 of vane 111. An arm 137 projects radially outwardly from the cover 37 of the deflector 31. The arm 137 is about 75 from the diametrical line joining the stop pin 115 and post 7 in a direction toward the second wall 41 of the deflector 31. A cord 139 is attached at one end to the outer end of arm 137. The cord 139 passes over pulley 133 and along the side of vane 111 to the top center of the post 7 where it is attached. The cord 139 is also attached to the lower end of one of the arms 127 on second vane 125 by a clamp 141. When the second vane 125 is attached to the cord 139 by the clamp 141, it is normally positioned to lean forward slightly toward ~2:297~r`~

the wind. If the wind begins to blow too hard, the second vane 125 begins to pivot about pin 129 causing clamp 14] to move toward the wind. This causes the cord 129 to pull the deflector 31 via the arm 137 against the action of the spring 117, to a position where the first wall 39 blocks most of the wind to the rotor 9 thereby protecting it from damage. As the wind subsides, the spring 117 pulls the wind deflector 31 back to its optimum posi;tion.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a windmill of the type comprising:
a hotizontal platform provided with a fixed, vertical, central post;
a rotor provided with a plurality of vertical vanes, said rotor being rotatably mounted about the post on the platform;
a wind deflector rotatably mounted relative to the rotor about the post on the platform;
means for rotatably positioning the wind deflector relative to the rotor and to the wind direction, to maximize the wind effect on the rotor; and the improvement wherein said wind deflector includes a first wall sized to shield at least half of the rotor from the wind and shaped to create a reduced pressure behind the wall to assist the rotor in rotating more efficiently.

2. The improved windmill of claim 1, wherein:
said first wall has an airfoil cross-sectional shape defining a trailing edge and a leading edge;
said trailing edge extends in a direction parallel to the axis of rotation of the rotor and lies adjacent an imaginary vertical cylinder generated by the rotation of the outermost portions of the vanes of the rotor; and said first wall extends tangentially from said imaginary cylinder to shield half the rotor from the wind.

3. The improved windmill of claim 2, wherein the wind deflector includes a second wall having its vertical center located at about 90° around the imaginary cylinder of rotation from the trailing edge of the first wall in the direction of rotation of the rotor.

4. The improved windmill of claim 3, wherein the second wall has a convex surface facing the axis of rota-tion of the rotor.

5. The improved windmill of claim 4, wherein the rotor comprises circular, horizontal top and bottom plates between which the vanes vertically extend.

6. The improved windmill of claim 5, further comprising means for overriding the rotatable positioning means to move the wind deflector to a position to reduce the wind effect on the rotor as the wind speed increases above a predetermined speed.

7. The improved windmill of claim 6, wherein said rotatable positioning means comprise cooperating drive means on the platform and the wind deflector, means for operating said drive means, and means operated by a weather vane for controlling said operating means, and wherein said overriding means comprise control means operated an anemometer, said control means operated by the anemometer overriding the control means operated by the weather vane.

8. The improved windmill of claim 6, wherein said rotatable positioning means comprises a vane rotatably mounted on the post above the wind deflector, a stop member on the top of the wind deflector, and spring means extending between the wind deflector and the vane to resiliently bias the vane against the stop member, said overriding means comprising a second vane pivotally mounted on the first vane transverse to it and means connecting the second vane to the wind deflector to rotate the wind deflector against the action of the spring when the wind moves the second vane.

9. The improved windmill of claim 8, including a circular track on the platform extending upwardly and inwardly, and rollers on the bottom of the wind deflector extending downwardly and outwardly to ride on the track.

10. The improved windmill of claim 1, wherein the wind deflector includes a second wall spaced from the first wall, said second wall lying adjacent the rotor and being shaped to direct wind onto said rotor.

11. An improved windmill of the type comprising:
a horizontal platform provided with a fixed, vertical, central post;
a rotor provided with vertical vanes rotatably mounted about the post on the platform;
a wind deflector rotatably mounted relative to the rotor about the post on the platform, the wind deflector including a wall sized to shield at least half of the rotor from the wind;
means for rotatably positioning the wind deflector relative to the rotor and to the wind direction, to maximize the wind effect on the rotor; and means for overriding the rotatably positioning means to move the wind deflector to a position to reduce the wind effect on the rotor as the wind speed increases above a predetermined speed, the improvement wherein:
said rotatable positioning means comprise cooperat-ing drive means on the platform and the wind deflector, means for operating said drive means and means operated by a weather vane for controlling said operating means, and wherein said overriding means comprise control means operated an anemometer, said control means operated by the anemometer overriding the control means operated by the weather vane.

12. An improved windmill of the type comprising:
a horizontal platform provided with a fixed, vertical, central post;
a rotor provided with vertical vanes rotatably mounted about the post on the platform;
a wind deflector rotatably mounted relative to the rotor about the post on the platform, the wind deflector including a wall sized to shield at least half of the rotor from the wind;
means for rotatably positioning the wind deflector relative to the rotor and to the wind direction, to maximize the wind effect on the rotor; and means for overriding the rotatably positioning means to move the wind deflector to a position to reduce the wind effect on the rotor as the wind speed increases above a predetermined speed, the improvement wherein:
said rotatable positioning means comprises a vane rotatably mounted on the post above the wind deflector, a stop member on the top of the wind deflector, and spring means extending between the wind deflector and the vane to resiliently bias the vane against the stop member, said overriding means comprising a second vane pivotally mounted on the first vane transverse to it and means connecting the second vane to the wind deflector to rotate the wind deflector against the action of the spring when the wind moves the second vane.