My last blog may have sounded like I didn’t think there was anything really new to be found in the gear trade. Actually I think there are numerous areas that could produce exciting developments; it is just that most of those ideas have been worked on before — but were discarded — as impractical under the technological restrictions of the time.
A recent example of this is the tremendous advances made in gear tooth grinding. Gears were being ground over a hundred years ago, but the costs were very high and the industry “worked around” the obvious advantages of highly accurate and smooth tooth flanks with lapping, shaving, and hand polishing. Over time, enough improvements were made in the mechanics of the process to permit ground gears in some very demanding applications. It took the convergence of improved drivetrain mechanics, gear materials, ceramics, computers, motion controls, sensors, and high demand to make gear grinding the everyday process it is today.
So where will the next breakthroughs occur? I have gone on record in favor of more widespread use of high-contact-ratio gear forms. We are seeing exciting progress in tooth forming in general purpose machine tools. Some “old” concepts for high-ratio systems using eccentric shafts may be worth another look. The advances in 3-D printing may revive old processes like investment casting.
Ever changing economics, improvements in related fields and better understanding of fundamental laws require a thorough knowledge of how things used to be done, are currently done, and could possibly be done. Things that make economic sense when oil is $100 a barrel are not necessarily valid when the price drops to $40.
Model T Fords were designed to run on ethanol because Henry Ford thought farmers could grow their own fuel, just like they did for horses. Refining processes and infrastructure were many years and two world wars away from allowing compression ratios over 5:1, and only recently has ethanol become a common motor fuel again. There are many valid gearing concepts that went out of common use or never reached their full potential because of the conditions of their time. In future blogs I plan to bring some of them to your attention.