The standard reciprocating pumps used at the bottom of the well effectively rely on the pump rod weight to return them, so pedal drives and small windrotors have to be geared slower. This gravity return also limits the stroke of the pump, so requiring a larger cylinder and borehole; and stiff rigid rising main as well as pump rods to transmit the small upstroke down to the cylinder. So maintenance of the pump and its valves is a very heavy and risky disassembly of the rods if not the rising main.
Our pullpumps have hydraulic return of the piston faster than gravity to allow faster (i.e. foot treadle) pumping at larger strokes, so the wellbore can be smaller and cheaper. And we can use continuous, flexible, lightweight and economical pump wire and rising main for much easier transport, installation, and maintenance. Our unique piston has a dedicated static seal below its working stroke for absolutely no leakback, and pulling it beyond its working stroke effortlessly releases the water column and brings all the valves and seals to the surface for incredibly easy and foolproof maintenance. In our Cottagepump rope can be run laterally inside a buried side pipe for pumping from inside a cabin even in winter.
Rotary windmills are so badly matched to pumping water that they convert only about 10% of the windpower they could capture into usefully pumped water. Their cranking cannot vary the stroke of the pump with windspeed . Variable stroke is inherent in our oscillating wing'dmills, as is our high wind protection, neither needing fallible add-on mechanisms. Our flutterwell model mounts a very short tubular tower directly on the well casing, for much lower and safer maintenance. Our floating Flo'pump eliminates the yaw bearing and tower entirely and the danger of losing prime for pumping from a pond, dugout, or dam. We are currently testing the Wing'd Pumps to drive piston air compressors for an even greater annual output advantage over using conventional windrotors, and for easy storage of wind energy.
History of our research and development
Based supposedly on an idea by G.I. Taylor, the initial wing'dmill project made Pocklington School in York the BBC Young Scientists of 1976. The panel of judges thought it had tremendous potential for Third World use. The science behind the device proved very sophisticated and is the first known constructive use of flutter which consumes over half the computation in aircraft design to avoid.
Dr. Farthing conjectured and proved both experimentally and theoretically the unrecognised fact that flutter may cease at an upper windspeed so that a fluttering windmill is actually inherently safe in high winds and simply does not oscillate. Amazing smoke video of the full scale wing flow shows a merging of stall and unsteady flow trailing edge vortices which explains the very high power levels achieved in light windspeeds. The oscillating motion is close to ideal for pulling reciprocating pumps to which conversely wind turbines are very poorly matched.
Well-based and floating prototypes now exist for pumping water with secondary equal pressure air output from the surge tanks. Secondary battery-charging and primary air compressing has also been field tested. This technology needs long-term field testing for fatigue in actual productive uses.
On seeing the wing'dmill video, David Parsons contributed the original concept of the pullpump cylinder. Farthing rearranged the piston to make it practical and build the first prototype. Parsons contributed to subsequent development, notably with the self-snifting of the flutterwell pullpump's surge tank. Divergence occurred after joint proving of Parson's idea for hydraulic instead of wire actuation. Subsequently Farthing alone substantially improved and rearranged the pump yet again to use standard seals and make small sizes practical possible for treadling very deep wells.
Early prototypes of the Flo'pump and Yardpump were setup at an appropriate technology center in Cuba, and contact has been attempted with bike factories in India, China, and Cuba over the backpedal brake. However, government foreign aid and support was lacking for such individual non-commercial approaches.
Help is gratefully acknowledged from the university and Gifford & Partners in Southampton, the Hamilton Foundation, the Science Council of BC, Fisheries & Oceans and NRC-IRAP, ADRA Canada; and individuals such as MJ Lighthill, EWH Gifford, LM Staley, Rosamund Hyde, Nils Lovrod, Susan Gage, Clem Wehner, Dave Smith, Alan Thomson, David Parsons, Mark Lenckowski, Ken Huish, Aneil Haere and countless others.
Click for rationalisation of the development from first concept to final configurations and comparison with other "wingmill" concepts.