ILLINOIS WINDMILLS

 

Engine Operation

 

The distinct advantage of wind engines is their ease of use.  Unlike custom windmills that had to be manually turned into the wind, wind engines automatically turn the sails into the wind.  In fact, an operator is not required to make adjustments of any kind to keep the engine operating at peak efficiency.  Regardless of weather conditions, wind engines are built to be self-regulating—they even brake if strong gales prevent safe operation.

 

 

Maintenance

 

Aside from a periodic visual inspection, not much maintenance is required to operate a wind engine—which is exactly how it’s designed to function.  Many are so well built that “tune-ups” are virtually unheard of.  All that is required of the operator is ensuring that the contact points are well-lubricated with gear oil.  On early wind engines, this required operators to climb the tower every few days to oil the gearbox.  Although this design was still a vast improvement from operating a custom windmill (that required daily maintenance with several large gears), it was not uncommon to hear of people losing their balance and falling to their death.

 

When safety became the top priority of manufacturers, designs were modified to make maintenance trips less daunting (or, at the very least, less frequent).  One short-lived model was the “tilting tower” design, in which the tower, centrally balanced on a hinge, flipped the windmill so that the gearbox could be oiled from the ground.  Another design was the “pull-the-wire” concept, in which the operator released more oil into the gearbox from the ground by releasing small amounts from a larger reservoir (of course, the tower still had to be climbed to refill that reservoir).

 

Ultimately, an innovation of the Elgin Windmill Company prevailed.  “Self-oiling” gearboxes required fewer than one oil change per year.  These operated with totally enclosed gearboxes that contained the oil within and protected the gears from weathering.  It did not take long for windmill manufacturers to borrow this design, which continues to prevail.

 

 

Speed Control

 

Halladay’s original patent called for four spring-hinged “self-furling” sails, which could, like modern wind turbines, turn upon their axes to alter the surface area exposed to the wind.  The sails were not mounted directly to the gearbox but rather to a set of axles: as the hub increased in rotational velocity, a spring control turned those axles to expose less surface area to the wind.  If the velocity dropped, the sails turned back to their normal position.   

 

When engine designs changed to employ rigid annular sails instead, Halladay addressed the speed control issue with the pivoting sectional wind wheel.  The sectional wheel similarly operated on a set of springs, but rather than turn the thin, individual slats of wood out of the wind, each of the six sections of the wheel opened to allow wind to pass through as demonstrated below: