Windpump

[2] Windmills were later used extensively in Europe, particularly in the Netherlands and the East Anglia area of Great Britain, from the late Middle Ages onwards, to drain land for agricultural or building purposes.

Windmills were already in use to pump the water out, but in Van de Molens (On mills), he suggested improvements, including the idea that the wheels should move slowly, and a better system for meshing of the gear teeth.

[3] Eight- to ten-bladed windmills were used in the Region of Murcia, Spain, to raise water for irrigation purposes.

[4] The drive from the windmill's rotor was led down through the tower and back out through the wall to turn a large wheel known as a noria.

A tower-top gearbox and crankshaft converted the rotary motion into reciprocating strokes carried downward through a rod to the pump cylinder below.

Many of these were built in The Broads and The Fens of East Anglia for the draining of land, but most of them have since been replaced by diesel or electric powered pumps.

[citation needed] Windpumps are used extensively in Southern Africa, Australia, and on farms and ranches in the central plains and Southwest of the United States.

[citation needed] In many parts of the world, a rope pump is being used in conjunction with wind turbines.

[10] Multi-bladed wind pumps can be found worldwide and are manufactured in the United States, Argentina, China, New Zealand, South Africa, and Australia.

The main design feature of a multi-bladed rotor is "high starting torque", which is necessary for cranking a piston pump operation.

[18] A piston pump has a very light suction phase, but the upstroke is heavy and puts a big backtorque on a starting rotor when the crank is horizontal and ascending.

[18] Control systems of the variable stroke wind pumps were mechanical and hydraulic; however, those experiments did not attract the attention of any windpump manufacturer.

[citation needed] Fluttering windpumps have been developed in Canada with a pump stroke varying strongly with amplitude to absorb all the variable power in the wind and to stop the uniblade from swinging too far beyond horizontal from its vertical mean position.

[19][20] A Turkish engineer re-designed the variable stroke windpump technology by using modern electronic control equipment.

The 30 kW variable stroke windpump design includes a Darrieus-type modern wind rotor, counterbalance and regenerative brake technology.

The Archimedean screw lifts water into a collecting ring, where it is drawn off into a ditch at a higher level, thus draining the land.