Vertical Axis Windmill Invention
Toronto Inventor Tom J. Gilmour recently published his conceptual designs for what he is calling Tom’s Whirligig. Patent applications have been made, and Tom hopes to reserve all rights and worldwide patents for his design. Tom believes his windmill plans to be the most complex ever devised. While he is not yet sure of the workability of this concept, he is optimistic about its feasibility and hopes to soon find the time to build a working model. His website provides detailed descriptions, illustrations, Google Sketchup files and a blog for visitor comments.

The focus of this new design is based around a continuously rotating carousel, which houses eight symmetrical airfoils. The entire carousel is mounted on a fixed vertical shaft. Each individual airfoil is meant to rotate 360° independent of the main shaft. A top mounted central weather vane keeps the cam shaft pointed at the wind. In high-intensity winds, the airfoils can be rotated to a zero angle of attack in order to prevent damage.
While tallest design that includes eight airfoils, he points out that the unit could theoretically work with more or less, as long as the tubular or central shaft is strong enough. Tom is recommending airfoils in multiples of 4, 8, 16, etc. for maximum efficiency. He believes there is no limit to the possible size and power output of his invention.
As far as strength goes, the main shaft, which is cemented in the ground, doesn’t move, so it can be as heavy as necessary to withstand any possible wind load. The carousel consists of a couple of wheels separated and affixed to each end of the tubular central shaft. Wheels can be made very light and strong (consider the wheel on a bicycle). The airfoils are attached to the carousel, at the top and bottom so that the main spar of the airfoils can be made much lighter. The weather vane and cam move very slowly and only with shifting wind direction. As far as the weather vane and cam are concerned, weight is not an issue. Hence, they could be made very strong. I would mount the airfoils so that their point of rotation was slightly forward of their center of lift so that they would have a natural tendency to weather vane. This would put a slight compressive force on the push rods and cam rollers. The force of the wind is transferred directly via the airfoil’s mounting bearings to the carousel. The push rods and bell cranks only control the attitude of the airfoils close to their center of lift, so they don’t need to be very heavy or strong. It would be possible to design this Whirligig with a fairly low rotating mass. Also, there is no chance of anything ever going supersonic unless you built a whirligig hundreds of feet in diameter (well maybe?). I have drawn the Tom’s Whirligig with eight airfoils but it would work with fewer or more. A carousel with only two airfoils might not start by itself. Three airfoils would work but probably wouldn’t be very balanced. I think a minimum of four airfoils would be practical. But 4, 8, 16, etc. (any even number above four) would probably work. One thing to note; it is possible at the low points on the cam, for the airfoils to go either clockwise or counterclockwise. It is very unlikely this would happen. An airfoil would go around backwards with its trailing edge pointing into the wind. But the perversity of mechanical devices says that if it can happen, it will. So I think it would be prudent, in considering the diameter of the carousel and the chord (width) of the airfoils, to design it such that the airfoils could pass each other, trailing edge to trailing edge, without interfering with each other. I don’t think there are any practical limits to the size of this whirligig. You could build one on the top of Mount Washington two hundred feet high.
Of all the possible uses Tom envisions for his invention, he is most excited about the possibility of mounting the windmill on top of a catamaran. He believes this would provide the boat with the ability to travel in any direction, including straight into the wind.
Tom is looking for other inventors working on similar ideas, and would love to see your inventions and sketch models, and hear your comments and suggestions. Here are some more resources for information about Tom’s Whirligig.
Tom’s Whirligig website:
http://www3.sympatico.ca/t.j.gilmour/
Tom’s Google Sketchup Files:
http://sketchup.google.com/3dwarehouse/details?mid=8186f1ce9ad5bb8ff597f2e89ae2e056
Tom’s Whirligig Blog:
http://whirligigwindmill.blogspot.com/
Related Information
YouTube: Hi-Energy Vertical Axis Wind Turbine Power System




As far as strength goes, the main shaft, which is cemented in the ground, doesn’t move, so it can be as heavy as necessary to withstand any possible wind load. The carousel consists of a couple of wheels separated and affixed to each end of the tubular central shaft. Wheels can be made very light and strong (consider the wheel on a bicycle). The airfoils are attached to the carousel, at the top and bottom so that the main spar of the airfoils can be made much lighter. The weather vane and cam move very slowly and only with shifting wind direction. As far as the weather vane and cam are concerned, weight is not an issue. Hence, they could be made very strong. I would mount the airfoils so that their point of rotation was slightly forward of their center of lift so that they would have a natural tendency to weather vane. This would put a slight compressive force on the push rods and cam rollers. The force of the wind is transferred directly via the airfoil’s mounting bearings to the carousel. The push rods and bell cranks only control the attitude of the airfoils close to their center of lift, so they don’t need to be very heavy or strong. It would be possible to design this Whirligig with a fairly low rotating mass. Also, there is no chance of anything ever going supersonic unless you built a whirligig hundreds of feet in diameter (well maybe?). I have drawn the Tom’s Whirligig with eight airfoils but it would work with fewer or more. A carousel with only two airfoils might not start by itself. Three airfoils would work but probably wouldn’t be very balanced. I think a minimum of four airfoils would be practical. But 4, 8, 16, etc. (any even number above four) would probably work. One thing to note; it is possible at the low points on the cam, for the airfoils to go either clockwise or counterclockwise. It is very unlikely this would happen. An airfoil would go around backwards with its trailing edge pointing into the wind. But the perversity of mechanical devices says that if it can happen, it will. So I think it would be prudent, in considering the diameter of the carousel and the chord (width) of the airfoils, to design it such that the airfoils could pass each other, trailing edge to trailing edge, without interfering with each other. I don’t think there are any practical limits to the size of this whirligig. You could build one on the top of Mount Washington two hundred feet high.



April 27th, 2007
I have seen a similar design for an under water current device that produces electricity from moving water. Presenly a similar design without the blades can be found on another web site for children in Africa to pump water from under the ground as they play. If Tom were to put some seats on his invention and to install it in place of the merry-go-round children’s water pump, it could serve to pump water from the ground and, at the same time, provide entertainment for the children. Tom has a really good idea.
adrianakau@aol.com
April 30th, 2007
Basically a Voith Schneider Propeller adapted to wind power. Should work but complexity brings reliability into question.
May 3rd, 2007
Years ago; during my research of wind turbine I have tested the basically the same design (just 4 airfoils instead of 8). Here my problem.
1- It requires too many moving parts (to turn the airfoil . . .).
2- The turbulence make those in the back become the liability rather then the asset.
3- I respect the “Inventor”. He may discover some other thing that I could not.
4- Any way we should cheer any effort in this area.
I you wonder how ours look alike then it is:
http://www.nextenergynews.com/windpower/windpower9.html
and
http://www.nextenergynews.com/hydropower/hydropower1.html
I hope this helps
Thanks
Phi
May 24th, 2007
Yrs & yrs ago my Dad built such a contraption - not based on aerofoils as yours seems to be, but with blades that were either perpendicular to the wind direction on one side of the tail axis, or folded away on the other.
This large contraption - 5 metres across - was cause for much hilarity. The inertia of the whole thing slowed its response to wind direction change too much - the result of which was a wild, octopus-like flapping and clanging. A great conversation piece - even if it never pumped water!
He lost interest in it at that point - so we’ll never know if he was onto something!
Good luck.
July 12th, 2007
It’s a Voith Schneider Propeller working in turbine mode-nothing new to it! Much research has already been conducted into such a device and in fact most variable pitch giromills work on the exact same principle. Complexity limits feasibility and performance won’t be higher than current vertical axis turbines.
June 10th, 2008
Tom, what is the present status of your wind machine? Have you built and tested a large model? I am working on a similar turbine with automatic control of the wings angle of attack etc.
What is your opinion of the large vertical mag-lev machine shown on, You Tube? I don’t know if is is real or not, but I suspect that it just exixts as someones dream. Your device looks like the wings are offset from the central axis so the moment arm is greater on the windward side. Maybe a good idea but how about balance during rotation?
Respond please if you can, Regards, Glen Bolton
June 16th, 2008
Very effective on low velocity of winds. It has twice of torque than the horizontal axis turbine. Furthermore, works on water current, low water current! More effective than traditional water turbine. We have similar (in concept) designs, based on our prototype made from biscuit’s can.