Javbw
> On Jun 13, 2017, at 8:13 PM, Warin <[email protected]> wrote: > > If you followed the history link I gave above you get They can be traced back > to the year 644 in Persia. Bit before the industrial revolution. The idea of using a wind driven shaft with a cam and a rod and a leather sealing element in a bored well for getting water out of the ground is really old. But those "windmills", I will assume, look like traditional windmills because of the structure needed to hold all the big heavy Main (wooden/bamboo) fan shafts and a driving shaft, cam, etc needed would have to have a small building of some kind - the stresses needed to pump water and handle wind load for wooden things with no bearings or gearboxes is pretty large if it is a permanent structure. Perhaps the really old ones in China were temporary, until a typhoon destroyed them. If it is some permanent thing, It's gonna be a building. I purposefully defined the traditional windmill as "operating some machinery" in the base - a mill, a trip hammer, a cam pump - whatever it happens to be - it is a building. A windpump: Using a small (mass-produced metal) transmission in a box on a derrick which can only move a rod up and down about 6 inches is similar only in that there is a fan disc - the building isn't present, the entire mechanism is in an outdoor gearbox, and the whole thing spins on the derrick because the gearbox is about the size of a suitcase on metal stilts. It can follow the wind because it has a tail (vane) that is the size of a car hood. The only thing of great significance is the gearbox the size of a suitcase. The rest a bits of metal angle-iron and sheet metal. A windpump can trace it's heritage back to the mechanism inside that pumped water a 1400 years ago - but so can all of those big permanent holland windmills - this is more about the structures - big buildings vs a box on a derrick - and a name to separate them. They are all generally called windmills - my father calls his "windpump" a windmill - in the same way a person calls train cars "cars" when they are power cars, or MPU cars, or some other name - but it is a easy way for people "in the know" to differentiate them. Javbw
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