Rotational Motion, Windmill, Waterwheel, Steam Engine, Compressed Air and Electric Power

Posted by PITHOCRATES - July 24th, 2013

Technology 101

The Combination of Force and Current of Moving Water on a Waterwheel produced Rotational Motion

Through most of history man has used animals for their source of power.  To do the heavy work in our advancing civilizations.  And they worked very well for linear work.  Going long distances in a straight line.  Such as pulling a carriage.  Or a plow.  Things done outdoors.  A long place typically from where people ate and slept.  So animal urine and feces wasn’t a great problem.  But the closer we brought them to our civilized parts of society it became a problem.  For it brought the smell, the flies and the disease closer to our civilized part of life.

Animals were good for linear work.  But as civilization advanced rotational work became more important.  For as machines advanced they needed to spin.  The more advanced machines needed to spin at a fairly high revolutions per minute (rpm).  We have used animals to produce rotational motion.  By having them walk in a small circle.  To slowly turn a mill stone.  Or some other rotational machine.  But it was inefficient.  As animals can’t work continuously.  Especially when walking in a circle.  They have to rest.  Eat.  And they have to urinate and defecate.  Making it unclean.  And unhealthy.

The first great industrial advance was water power.  Using a waterwheel.  Spun by a current of water.  Either a large force of water moving slow and steady.  Like in a river.  Or a small force of water moving fast and furiously.  Like in a small waterfall.  This combination of force and current produced rotational movement.  And useable power.  The waterwheel produced a rotational motion.  This rotational motion drove a main drive shaft through a factory.  Gear trains could speed up the rpm produced by a slow river current.  Or reduce the rpm produced by a fast waterfall current.  To produce a constant rotational speed.  That was strong enough to drive numerous loads attached to the main drive shaft via belts and pulleys.

Compressed Air Systems allowed us to produce Rotational Motion at our Workstations

Water power was a great advancement over animal power.  But it had one major drawback.  You needed a moving current of water.  Which meant we had to build our factories on the banks of rivers.  Or under a waterfall.  One of the reasons why our first industrial cities were on rivers.  The steam engine changed that.  With a steam engine providing our rotational motion we could put a factory pretty much anywhere.  And the power of steam could do a lot more work than a moving current of water.  So factories grew larger.  But they still relied on a rotating main drive shaft.  Then we started doing something else with our steam engines.  We began compressing air with them.

A current of air can fill masts of sails and push ships across oceans.  Air has mass.  So moving air has energy.  We’ve used windmills to turn millstones to crush our wheat.  Where a large force of a slow moving wind current filled a sail.  And pushed.  But these small currents of air required large sails.  If we compressed that volume of air down and pushed it through a very small air hose we could get a force at the end of that hose similar to what we got with a sail catching a large volume of air.  This allowed us to create rotational motion at a workstation.  Without the need of a rotating main drive shaft.  We could connect an air hose to a handheld drill.  And the compressed air in the air hose could direct a jet of high pressure air onto an ‘air-wheel’ inside the handheld drill.  Which spun the ‘air-wheel’ at a very high rpm.  Spinning the drill bit at a very high rpm.

Compressed air was a great advancement over a rotating main drive shaft.  Instead of belts and pulleys connecting to the main shaft you just had to plug in your pneumatic tool to an air line.  The steam engine’s rotational motion would drive an air compressor.  Typically turning a crankshaft with two pistons attached to it.  When a piston moves down the cylinder it draws air into the cylinder.  When the piston moves up it compresses the air in the cylinder.  The compressed air exits the cylinder and enters a large air tank.  From this air tank they run a network of pipes throughout the factory.  From these pipes hang air hoses with fittings that prevent the air from leaking out.  Keeping the whole system charged under pressure.  Then a worker takes his pneumatic tool.  Plugs it into the fitting on a hanging air hose.  As they snapped together you’ll hear a rush of air blow out.  But once they snap together the joined fittings became airtight.  When the worker presses the trigger on the pneumatic tool the compressed air blows out at a very high current.  Spinning an ‘air-wheel’ that provides useful rotational
motion.

Electric Power generated Rotational Motion eliminated the need of Steam Engines and Compressed Air Systems

As good as this was there were some drawbacks.  It takes time to produce steam when you first start up a steam engine.  Once you have built up steam pressure then you can start producing rotational motion so the air compressor can start compressing air.  This takes time, too.  Then you need a lot of piping to push that air through.  A piping system than can leak.  It was a great system.  But there was room for improvement.  And this last improvement we made was so good that we haven’t made another in over 100 years.  A new way to provide rotational motion at a workstation.  Without requiring a steam boiler.  And air compressor.  Or a vast piping system charged with air pressure.  Something that allows us to plug in and go right to work.  Without waiting for steam or air pressure to build.  And that last advancement was, of course, electric power.

When voltage (force) pushes an electrical current through a wire we get useable power.  Generators at a distant power plant produce voltages that push current through wires.  And these wires can run anywhere.  In the air.  Or underground.  They can travel great distances at dangerous high voltages and low currents.  And we can use transformers to change them to a safer low voltage and a higher current in our factories.  And our homes.  Where we can use that force and current to produce useful rotational motion.  Using electric and magnetic fields inside an electrical motor.

Animals were a poor source of rotational power.  The windmill and the waterwheel were better.  The windmill could go anywhere but the rotational motion was only available when the wind blew.  Waterwheels provided continuous rotational motion but they only worked where there was moving water.  Keeping our early factories on the rivers.  The steam engine let us build factories where there was no moving water.  While an air compressor driven by a steam engine made it much easier to transfer power form the power source to the workstation.  While electric power made that transfer easier still.  It also eliminated the need of the steam engine and the pneumatic piping system.  Allowing us to create rotational motion right at the point of work.  With the ease of plugging in.  And pressing a trigger.  Allowing machines to enter our homes to make our lives easier.  Like the vacuum cleaner.  The clothes washer.  And the air conditioner.  None of which your average homeowner could operate if we depended on a main drive shaft in our house.  Or a steam engine driving a pneumatic system.

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