Friction drive wind turbine

panurge

10 kW
Joined
Feb 3, 2011
Messages
628
Location
Firenze - Berlin
Hi guys

I've got Just this simple Idea....then googling for it I found that, at least in large scale, this has already be done.....but what about a wind turbine laced to a complete bike wheel ( I mean with tire) as a flywheel and some small generators friction driven by the wheel's tire? (outrunners as an exemple)
A gearless turbine could have some big advantages... A way to control the distance between rotors and tire functionally to the wind power, could be another cool idea....and the option to may also use automated disk brakes with off the shelf mechanical components if needed....
A front Enduro Motorbike dual disk wheel could be used too or any vehicle wheel (mmh, figuring out a big one with the rear tire of a Tractor....)
As I'm used to work with Bikes and have a windy farm and mostly as I have a small budget ready for a wind project, I'm a perfect candidate to try something like this....also, It's since 5 years I'm monitoring the wind there and the average speed is 4.4 m/s with 12+ m/s continuous peaks (>120 minutes per day) for at least 120-150 days per year.

My lack of time and the really basic E-skills I have, are the major limits, but have a buddy (next farm from mine) that was an electrician before to start his second life as a farmer....

Anyway I'm interested in any Wind turbine option you guys have to suggest....

Cheers
 
How would you adjust the ratio between the bike wheel and motor? It seems a chain drive with sprockets would also be more efficient and allow you to adjust the ratio.

I am about to build my first wind turbine too, though my house is not in a great windy spot, too many trees and houses nearby. I think vertical axis is the way to go, so you don't worry about the wind direction.
 
Good concept. I have seen a bicycle wheel with fan blades made of sections of PVC pipe cut lengthwise with a bit of twist along the length. It had a v belt driving the little tread mill motor that was used as the generator. A proper fan blade would be better.
 
veloman said:
How would you adjust the ratio between the bike wheel and motor? It seems a chain drive with sprockets would also be more efficient and allow you to adjust the ratio.

I am about to build my first wind turbine too, though my house is not in a great windy spot, too many trees and houses nearby. I think vertical axis is the way to go, so you don't worry about the wind direction.

Haven't deeply analyzed the concept...but as per Amberwolf advice....the roller diameter, the wheel size and the tire size itself could help on that.....using chain and sprockets means gears.....and, mostly, precludes a multi motor setup.....
As an example, I could figure out a more sophisticated system where the number of the engaged generators is a function of the blades rpm and the pressure of the rollers could be adjusted too, this could be reeeally advantageous. In fact this means like to have a single alternator that dynamically change his power with the wind speed, a dream for any Wind turbine engineers....virtually you could achieve a perfect alternator with an input power that rises with the cube of the wind speed.

My house is at 700 meters of altitude and placed just at the ridge of a high hill, I have 60% of the wind direction from West, a 30% from East and the rest from the others directions...
If you are not in a windy place with no-prevalent wind directions, and mostly if you plan to use the turbine at the house's roof, than a vertical axis should be the best choice...The friction drive concept could fit the vertical axis too, maybe even better.... with a plane wheel base and vertical axis alternators.... :wink:
In my situation I have enough speed for conventional blades and I plan to put the turbine at a new pylon similar (10 meters) to the one where actually the wind monitoring station operates but obviously bigger...DSCN0499 (Copia).jpg :wink:

That's an already working large scale friction drive turbine http://www.cwind.ca/html/65kwp.html in the 2MW prototype section you could see a 3d animation of the concept.
 
I don't know how much studying or actual info you have under your belt, but, in the photo, you seem to have that pole fairly close to the edge of that hill.

If you don't realize it, as the bulk of the wind approaches that hill, it has to rise up to get over the hill. This means that the mass of the wind will rise up and over the turbine, instead of being directly into the turbine.

I sold and installed about 30 1-3KW wind turbines, and, my favorite project was seeing a wind turbine installed on top of a 5 story office building in Fort Smith Arkansas, by college engineering students
The turbine never put out 1 watt of power. It was an Enertech model that had a brake holding the prop from turning, until the wind was at 8 MPH. We offered assistance or to even buy the turbine, but, we were flatly turned down. I guess they did not want to embarrassment of seeing UNeducated people solving their simple problem. :roll:

The forces of the wind striking the flat side of the building, forced all the wind up and over the turbine.

IF you want to, you can take a long thin pole, attach a ribbon on the top, and slowly raise the pole to vertical and watch the ribbon. You will see a stronger wind as you go higher.

Wish you well in getting a good working turbine installed and charging.

Harold
 
Well, I opened the thread only because I had this simple idea of a small DIY friction drive turbine starting from a friction drive e-bike setup. then, the imagination has galloped :oops:

Anyway I think I am "educated" enough about this theme, mostly from my personal study but I also got courses of various involved subjects At Uni, some years ago.....however, I have not enough practice. This will be increased soon, I hope...

Wind efficacy rises with elevation from the surface where the pole is installed until a certain value, mostly a function of the obstacle's high, wind speed, and sleep of the windward side, than the elevation from the main plain becomes the preeminent factor and losses due to the obstacle (natural or anthropic) drastically decrease and disappear.
In theory a wind mass slower than 4-5 m/s is supposed to flow in an ordinate motus in any case.
The best way to know the wind would be to use the turbine itself, though :wink:
Harold in CR said:
as the bulk of the wind approaches that hill, it has to rise up to get over the hill. This means that the mass of the wind will rise up and over the turbine, instead of being directly into the turbine
That's a good point......of course the wind's study for hilly places is not easy as for flat-lands......I have approached this question using another anemometer and moving it around there and determined from compared datas, that whenever turbulence starts, it never happens before a measured speed of 6-7 m/s and usually the wind than evolve to a 15-20 m/s storm where the rotor should be stalled or inefficient anyway....... I wonder if those AK's E-Students have measured the wind in a correct way for a sufficient time....

The pole in the pics is not properly at the top, the hill is not so steep in the prevalent wind direction and the top is not a peak but more like a plum-cake ridge, anyway 10m is the actual high but a 5Kw rotor true pole would be taller by several meters, so I should expect even better values....

I post this link as reference for the kind of commercial 5kw turbine I would look for if I had enough budget....they are relatively close (400 miles from me) and mostly they sell also E-bikes in various styles.... :D

Thanks for your professional point of view and your wishes, your advice about the wind efficacy shows that you know well what you are saying, so I will ask you things as I'll start the practice.. :wink:
 
This company is a few miles away from me. At the top of the 5 story building they are in, are their actual turbines. They take advantage of the wind pushing up the side of the building and over the edge.

http://buildingturbines.com/products.php

Here's a google satellite view pic:

https://maps.google.com/?ll=30.344471,-97.71265&spn=0.00057,0.000487&t=h&deg=90&z=21
 
Interesting.....If Wind blows mostly from the same quadrant, than it's an intelligent application of a perpendicular (to the wind) axis turbine. Great for Industrial buildings and for who has the opportunity to play with an entire roof top.
The friction and the multi-alternator concept could still be applicable there, and - let my imagination gallops - even improved....
Immagine: a battery of sprague clutched horizontal perpendicular axis rotors with a brake system each, that friction drives a battery of alternators.....and add an electronically automated wind dependent control that add/removes rotors/alternators to the line.....a bit redundant but fascinating...
Uhm...This could be even better mechanically made with bike's wheels now that I think about....and maybe in a cheap non-friction way with hubmotors laced :mrgreen:
Ok end of the cavalcade :D
but Well, I'm convinced, as I have an half hour, I'll try to model something :mrgreen:
Thanks for the imput Veloman
 
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