CA2158491A1 - Vertical axis wind turbine - Google Patents

Abstract

A vertical axis wind turbine apparatus, for converting the kinetic energy of the wind into usable force in a rotary manner as to turn a mill or drive a generator suitable for the home or business.
The turbine apparatus consists of three fixed flat vanes, mounted vertically between two flat horizontal discs. The vanes are bent at both ends, at precise angles and different locations from their respective ends. There are three movable control vanes which are mounted 15 degrees behind the fixed vanes in a clockwise rotation.
The movable or adjustable vanes are controlled by vertical shafts which can be adjusted to various positions while the turbine is in operation. Adjusting the movable vanes affects the pressure and velocity within the turbine, causing changes in the turbine's speed. The fixed vanes are positioned at 120 degree intervals in rotation from each other and 55 degrees off centre to the turbines pivot point. The vanesare all positioned so as to allow the wind constant flow through the turbine at all times, even when stopped.
The adjustable vanes, when in the working mode, will increase the wind velocity and at the same time direct the force towards the vanes that are ahead in rotation and are moving out of the wind's direct force. The adjustable vanes cause a nozzle effect on the blind vanes for up to an additional 90 degrees in the null area ofrotation.
From that point there is some negative or reverse effect, but only on the fixed vanes since at that point the adjustable vanes are shielded. Because the area of wind contact on the rear of the fixed vanes is 20% of the area in contact with the wind on the front or positive side of the vanes, the negative effect is overwhelmed and the turbine keeps on turning. To control the adjustable vanes, a worm gear device with links and arms turns the shafts supporting the adjustable vanes from above the turbine. Power to operate this device is fed through carbon brushes and slip rings from below the turbine. Very low current is used to reduce wear on the slip rings and brushes. The adjustable vanes can be positioned to cause a perfect balance of wind pressure on both sides of the turbine, in order to bring the rotation to a complete stop. In the event of mechanism failure, the adjustable vanes will act from centrifugal force to limit the turbine's speed.
The turbine is fitted with a centre hub that must be of a specific dimension in order to form a nozzle area in combination with the two vanes. (see specifications.) Two sealed ball bearings are fitted in the hub, one each at the top and bottom. The complete assembly is then mounted on a hollow axle which extends below the turbine and slip rings into an adapter bracket. The complete assembly is mountedon a suitable tower. The drive is taken from the top of the turbine via a drive flange and drive shaft. The drive flange is bolted through the upper disc and into the centre hub.
The drive shaft is keyed to the drive flange and extends down through the hollowaxle to the load below the turbine. A centering bearing is fitted in the bottom of the support bracket, in order to keep the drive shaft in alignment with the load.

In areas where the wind direction is constant within 30 degrees this turbine can be mounted horizontally, on the crest of a beach or hill where the wind speed is usually higher.
With the use of aluminum sheets and/or honeycomb panels, this turbine will be very simple to construct. Needing only close radius bends on flat sheets, with standard size ball bearings, and the use of a metal turning lathe, a 2 kilowatt unit can be built for $800.00 Cdn. An old TV antenna tower will serve as a suitable tower for the turbine. This turbine will not harm migratory birds, as they will be deflected or simply pass through the turbine.
The speed of the turbine will be between 600 and 1,000 RPM. The rotor is designed to start with only a 7 MPH wind, and noise levels will be nearly zero.

Description

~ l~g~ql Backqround of the invention:
15 With the increasing need for a non-polluting renewable power source for the generation of electricity world wide, many types of wind machines have now been developed. Some are so expensive that they are beyond the means of the average - farmer or people in developing and 3rd world countries.
Some of these machines have proven to be uneconomical to operate and some are 20 downright dangerous. The most successful wind machine on record is the popular propeller type working on a horizontal axis, using the lifVdrag principle. Thesemachines must be oriented to face the wind at all times. This means that the driven unit must be rotated back and forth in conjunction with the turbine. Most also carry a transmission and brake assembly. To add to the dilemma the propeller type 25 turbine and its components must usually be mounted on a tall tower in order to catch the upper, stronger winds. Since the whole assembly must rotate back and forth, the electricit,v generated must flow through carbon brushes and slip rings.
This requirement limits the amount of power that can be generated safely. In addition, maintenance on these units is frequent and costly, also the inherent height 30 required precludes this task from being carried out by the layman.
A Vertical Axis Turbine now will have the generator and auxiliary components on the ground or at a safe height bellow the turbine. There will be no need to rotate the unit to face the wind. The turbine will operate in winds from any direction (36035 degrees). Maintenance will be minimal since there will be fewer moving parts. Low-tech components can be used, those commonly known to the average mechanic.
To date, all Vertical Axis Wind Turbines developed around the world have failed due to two basic reasons.
Firstly, they use the planar and drag principal similar to a sailing ship. This is fine for 40 a ship which must travel in straight lines, relative to the wind, but for a rotating turbine the effect only lasts for a very short time during one revolution for each vane.
This makes it questionable as to their capabilit,v to produce "drive".
Secondly, none have shown a practical method to control the speed of the turbine in high winds. In the event of generator failure, the turbine will overspeed to the point 45 of its own destruction and with the possibility of danger to human lives.
This invention is a Vertical Axis Wind Turbine that uses wind pressure and changing wind velocity internally to drive the rotor. The effect works for up to 220 degrees of revolution for each vane. The remaining 140 degrees are canceled due to the shape and positioning of the flat vanes. It has constant speed control and overspeed protection.
With reference to U.S. Patent No 4359311 16 Nov. 1982, U.S. Patent No 4005947 1St Feb. 1977, U.S. Patent No 3942909 gth March 1976 and others, all fail to show how the speed is controlled in normal operation or in the case of an overspeed. As well all are very difficult to construct and will be very expensive to own and maintain.
This invention is a turbine that is simple to build and will cost a fraction of the cost of an average automobile. Built on a larger scale, even utility companies could use it.
The materials used in its construction are in great supply in most countries around the world. With flat, close radius bends, any skilled sheet metal worker with access to a metal turning lathe and a metal break can build a 2 kilowatt unit for $800.00 Cdn. A used TV antenna tower can be used to support it. The actual size of the turbine will depend on the average wind available in the area.
SUMMARY
Migratory birds will not be harmed by this turbine should it be constructed in their flight path. The noise level will be nearly zero, simply a whisper above the hum of the generator. If produced in mass assembly quantities, the cost would be considerably reduced. This turbine has the added feature of being able to be adapted to drive a mill or a water pump through the addition of angle drives andworm gears, etc.
Drawin~s and S"ecirications Brief description and list of drawings The objects and features of the invention may be better understood with reference to the following detailed illustrative drawings.
Fiqure 1.
Shows an artists impression of what the invention might look like on top of a tower.
Fiqure 2a.
Shows a bird's eye view, looking down on top of the turbine, coined with an x-ray view of the fixed vanes (2), and the adjustable vanes (4). In the position shown as (A) one can see the adjustable vanes in the fully open position. In the positionshown as (B) one can see the adjustable vanes in the stop or shutdown position.
Fiqure 2b.
Shows a cross section drawing of the hub (fl and the sealed ball bearing (h) supporting the turbine discs (b). The complete unit is mounted on the hollow axle (I) which is then clamped or pressed into the mounting adapter (d). The drive shaft extends down from the drive flange (a) through the centering bearing (k) to drive the electric generator (e).
Fiqure 3.
Shows the invention in % view with related components identified by numbers, forreference to the specir,calions.

` 4 2l5849 Fiqures 4, 5~ and 6.
Shows an x-ray view of the vanes as viewed from above the turbine showing the changes that take place to affect speed control. The path of the wind is also shown when the adjustable vanes are moved.

Fiqure 7.
Shows a cross section view of the fixed vanes revealing the exact locations and angles for mounting the fixed vanes vertically between the discs.
10 Fiqures 8 and 9.
Show a cross section view of the fixed vanes, revealing the formula for obtaining the size of the fixed vanes and the location of the bends on the flat material (the location of both bends must be marked off before bending).
Fiqure 10.
15 Shows a cross section view of the adjustable vanes, revealing the exact location of the control shaft in relation to the fixed vanes.
Fiqures 11 and 12.
Show a cross section of the adjustable vanes, revealing the exact formula for 20 obtaining the size of the vanes and the location of the bends.
Specifications.
Turning now descriptively to the drawings, in which similar reference charactersdenote similar elements throughout the various views.
Commencin~ with Fiqure 3.
Three fixed flat vanes are positioned vertically, at 120 degree intervals between two flat horizontal discs. (1) The vanes are formed from flat sheets with one bend at each end and the exact locations and angles are shown. Three adjustable control 30 vanes (4) are mounted on a pivot shaft (5) and are positioned 15 degrees offset from the fixed vanes in relation to the centre of the turbine. The control mechanism (9) is connected to the control shafts (5) by direct links and arms to change the position of the adjustable vanes (4). The adjustable vanes direct the wind as itenters the turbine openings through a nozzle area between the tail of the fixed 35 vanes, and the centre hub (3). Here the wind velocity increases and it is forced to contact the two vanes that are on the null or reverse side of the turbine. Pressure is applied on these vanes to increase the contact area in the positive direction ofrotation which overwhelms the negative action by a ratio of 4 to 1 (see figure 4).
40 Fiqure 5.
Shows the control vanes (4) in a reduced speed position. In this mode the wind velocity decreases through the turbine and at the same time the edge of the adjustable vanes enters the negative area, causing the wind pressure to effect the reverse side, slowing down the speed of the turbine.
Fiqure 6.
Shows the control vanes in the stop position. In this mode the wind is directed around the turbine on both sides. On the reverse side the end of the adjustable vanes (4) are actually in contact with the fixed vanes (2) sealing off the entrance of - 2t58491 ~ any wind to the fixed vanes. At the same time the control vanes (4) are extended past the edge (diameter) of the turbine. This extra area protruding into the negative or reverse side acts as an air brake, stopping the rotation.
The flow through effect is also reduced considerably and an air pocket is formed5 internally. This turbulence forces the wind to exit the turbine equally on both sides of the vanes at the rear. The turbine stops turning due to- a balance of pressure on both sides. In very high winds, this will cause a pendulum effect behind the centre hub (3). The rocking motion which will result can be stopped by a mechanical brake acting on the drive shaft, although in high wind periods allowing the turbine to rock 10 back and forth will reduce the pushover pressure on the tower.
Fiqure 2b.
Shows how the turbine assembly is mounted on a hollow axle (I) with sealed ball bearings (h). The hollow axle (I) is mounted in a solid adapter (d). The drive shaft 15 (j) is keyed to the drive flange (a) above the turbine.
A sealed ball bearing (k) is fitted in the bottom of the adapter (d) in order to keep the drive shaft in alignment for coupling to the load either directly or though universal joints.
20 Fi~ure 7.
Shows the exact location of the fixed vanes (2) in relation to the centre of theturbine. The pre-formed vanes are set at 55 degrees, gauging by the outer end surface and a straight line to the centre of the turbine. The position for mounting the control shafts [5 (fig. 3)] is at a point 15 degrees ahead of the aforementioned25 straight line and at a point of 75% of the rotor's radius. Shown also is the diameter of the hub, which must be 11% of the rotor's diameter.
.

Flqure 8.
Shows the location of the close radius bends in forming the fixed vanes [2 (fig. 3)].
30 There must be two bends on the same side of the material and each bend must be 135 degrees. One bend must be at a point of 15% of the length to form the inner bend. The second bend must be at a point of 30% of the length of the flat material to form the outer bend on the opposite end. ~AII bend locations must be marked off before formin~.
Fiqure 9.
Shows the length and width of the material for forming the fixed vanes. The length must be 55% of the rotor's diameter, and the width must be 33% of the rotor's diameter.
Fiqures 10 and 11.
Shows the locations and angles for forming the adjustable control vanes. The flat material must be bent at both ends, but on opPosite sides. The first bend must be at a point of 38% of the length of the material and the angle must be 150 degrees 45 (the outer section). The second bend must be at a point of 25% of the length of the material and the angle must be 135 degrees (inner section). lMark off bend locations before forminq.]

Assemble the control vanes, to the control shaft, so as to form an "S" when they're viewed from above the turbine.
Fiqure 12.
5 Shows the length and width of the material for forming the adjustable vanes. The length of the flat material must be 38% of the rotor's diameter. The width of the adjustable vanes must be the width of the fixed vanes less .250", this will allow a .125" clearance above and below for free movement between the upper and lower discs. Mounting holes for bolting the vanes to the control shafts must be dead 10 centre of the centre section of the adjustable vanes. Assemble the vanes to the shafts with the larger section towards the outside of the turbine.

Claims (6)

1. A vertical axis Wind Turbine apparatus, that is simple to build, and will not cost more than or 25% of the cost of an average compact automobile in the 3rd world or developing countries. A 6' diameter Turbine will give its owner 1,000 watts of electricity in a 20-25 MPH wind (app. 1 HP).

2. A wind driven Turbine that will not harm migrant birds, and will not create very much noise. The noise level will be nearly zero. There will be a whisper above the hum of the generator, if used for generating electricity.

3. The Turbine will have constant speed control and overspeed protection.

4. The Turbine is designed to start generating power with a 7 MPH wind, and will operate in winds from any direction (360°).

5. The adjustable vanes can be positioned to cause a perfect balance of the windpressure on both sides of the Turbine in order to bring the rotation to a complete stop.

6. The adjustable vanes cause a nozzle effect that keeps the wind pressure on a particular vane for an added 90° in the null area of the rotation.
All claims are providing that the Turbine is built as per the specification enclosed herewith.