Inasmuch as there were at one time a couple hundred windmill makers in the U.S., I’m only going to talk about a few of the more common ones, their similarities and differences. Windmills have been around for a very long time, but self-oiling units are, in the whole scheme of things, fairly recent arrivals on the scene. For a long time, oiling windmills was accomplished by owners or employees climbing up the tower and physically filling either the oil reservoirs (consisting of a cast iron area above the bearing in question, filled with cotton waste. Oil was poured onto the cotton waste, the theory being that oil would slowly run down and keep the babbitt at least slightly lubricated) or the grease cups (which were filled with “hard” oil, the cap replaced and then screwing the plunger down a little. This would be repeated until the cups were empty and then the process was begun again).
One company went so far as to have a brass rod from the hard oil cup (with special material in it) riding on a shaft. In theory, the brass rod would get warm and grease would ooze out into the bearing area. Surely this would work well at 20 or 30 degrees below zero, yes?
Early windmills needed little fresh oil
Fast-forward a few years: Dempster Mill & Mfg. built its No. 11 mill, which employed an oil “scoop” to bring oil up and out to the front bearings. Later came the No. 15, another direct-stroke mill, which self-oiled quite well. Moving lubricant was accomplished via small trays that brought oil up and dumped it in higher places.
Following these direct-stroke mills, Dempster came out with its No. 12, bragging on the tail “Annu oiled.” In reality, from what I have seen when taking down windmills over the years, very few saw fresh oil but still managed to keep pumping with very little wear. Oil used in mills is a very light oil, as well as being non-detergent, so as not to carry anything in suspension but rather to leave dust and debris in the bottom of the motor bowl.
As time went on, Dempster windmills employed (even on early No. 15 mills) a pair of Timken tapered bearings with a spring pre-load on the fan shaft. Our No. 15’s bearings are still bright and tight, as is the rest of the mechanism, a tribute to oiling system shown in the photos accompanying this article.
Comparing oiling mechanics of different antique windmills
“Andrew,” a mill produced by Duplex Mfg. Co., is nicely engineered. The fan shaft gear drives an internal gear inside the pumping mechanism, thus two teeth contact the gear as opposed to external gears doing the job. Much of the oiling here is done via a scraper atop a large internal gear that simply scrapes copious amounts of oil off onto places where it is needed. Another interesting feature of this mill is the fact that the fan can be built up on the ground, taken up and secured to the fan shaft with three bolts.
Going further, the first back-geared, internally oiled Aermotor windmill, the No. 502, did not fare so well. A spring wire arrangement was, in theory, supposed to flick oil to the upper works – which it didn’t. Most of these were called back. Luckily, we found one atop a 100-ft. tower, brought it home and had it restored at Dakota Windmill in Hurley, South Dakota. This mill only lasted a year, with the 602 coming out in 1916 with a simple oiler, as seen on pictures of the 702 accompanying this article.
Woodmanse, out of Freeport, Illinois, employed a toothed oil-pickup to bring oil to the upper works where it would flow out and catch pivoting points as shown.
The Beatty Pumper, a mill from Canada, looks similar to the Aermotor but is quite different when viewed up close. The upper works are oiled via a spring, wrapped around one pitman arm, which worked successfully. The mill itself is not fancy, the arms supporting the fan sections are simply pieces of gas pipe, screwed into the windwheel hub, bent and drilled on end to accept the outer blade supports, with a small bracket welded on to catch inner support. Again, not fancy, but functional.
Self-oiling was a great leap forward for windmills, eliminating climbs on slippery, ice-covered towers in winter, as well as ending weekly greasing, which no one did anyway! So it goes. FC
Jim and Joan Lacey operate Little Village Farm, a museum of farm collectibles housed in 10 buildings at their home near Dell Rapids, S.D. Contact them at (605) 428-5979.
Originally published as “How Did They Do It?” in the September 2023 issue of Farm Collector magazine.
