A wind-powered water/air pump

I've been playing around with a few ideas for a small scale wind-powered pump to provide some aeration or a small water feature for my pond-in-a-bucket (in the meantime I've gone off-the-shelf solar - different post)

Today was the first day we've had some wind in a while (I see a flaw in my overall plan!) so gave my little prototype a go - meccano (I actually went out and bought a set), a syringe-like piston and some blades made from length-wise sections of PVC pipe - showing some promise - I was actually really surprised by the speed it picked up in the first section of the clip - the mysterious powers of aerodynamic lift...

 

Nice bit of ingenuity with the syringe
I made a horizontal windmill some years back and that was a fun project, the sails folded flat as they turned into the wind to reduce drag and create lift like an aeroplane wing..It was 5ft x 5ft and generated a lot of torque at low windspeeds.
Here`s a pic of one powering a couple of bike pumps for pond aeration (30"- 48" rotor needed), i`ve seen them used to drive wooden garden toys like a 21" wingspan owl that "flies" lol


Heres a multi bike pump arrangement. Using 3 pumps offset by 120 degree`s is the optimum for smooth air output. The rotary arrangement in the 1st pic will have fewer losses but its harder to build. Could make a nice winter project..

 

forgot to check back on this thread - nice work there Hex_2011 - that three pump arrangement is a thing of beauty to see running - funnily enough was thinking about more than one piston on the cam - a single piston will give a very on-off-on-off movement of water or air - but I don't know if a wind turbine could ever self-start trying to drive more than one piston

my little arrangement was originally tried with a vertical axis - solely drag-based like an anenometer - better torque but I don't think it would ever turn fast enough

your horizontal windmill is intriguing - can use drag and torque to self-start and then lift at higher speeds to spin faster than the wind speed - you got any more details on that design???

p.s that owl looks like it's break dancing!

 

Hi
The owl is quite nifty, its operated by a series of cables (inner and outer cables like bicycle brakes) that are pulled in sequence as the windmill driveshaft rotates..The cable lengths can be adjusted independantly to control the amount of travel.
A high torque, low speed horizontal windmill is ideal for pumping applications. The windmill design is pretty simple, lightweight and cheap compared to typical savonius types which are made from half barrels or S-shaped metal sheets. When the backside of those face into the wind they tend to act like airbrakes.
In the design above, the square rotor carrying the sails is attached to the central hub (and vertical driveshaft) by flexible lines which hold it in position by tension. When its not rotating the rotor is suspended by the lines and it hangs slightly below the hub. When it begins to turn it creates its own lift and floats just above the hub, no weight on the hub at that point.
As for the sails, they operate in opposing pairs, each pair of sails is connected together by a cable. When one sail opens, it actively pulls its mate opposite shut at the same rate. As one sail spills wind it acts as a damper for the sail filling with wind so the open/close transitions are very smooth and controlled. Its fascinating to watch..
.If you build a fairly big windmill, its a good idea to incorporate a section of weaker cable for the sails which will break and release the sails in the event of a hurricane..The windmill will resemble some kind of weird rotary washing line but at least it`ll be safe.

Now you`ve got me thinking about building another one .

Here`s the mechanics of the triple pump arrangement.

.