Recently I learned that it took over 20 years for the gear industry to agree on its first “standard” tooth form — and that was after spending 25 years experimenting with alternative forms. We have been using a reprinted magazine article for the rating of splines for almost sixty years. Despite the high interest in epicyclic drives for wind turbines, we still don’t have an AGMA rating method for the bending strength of internal helical gear teeth.
One was first proposed in 1953!
We are making progress on the internal helical gear bending strength; look for it to be included in the next version of the basic gear rating standard, perhaps as early as 2015. A committee was formed to develop a spline rating standard several years ago, but progress has been slow. With the amount of splines used in machinery and vehicles, this topic should be getting more attention. Perhaps the method reprinted in Machinery’s Handbook is all our designers need.
Standards development is a collaborative effort and reaching consensus takes time. Gone are the days when a single gear company could take on a major “science project” and share the test results with the rest of the industry. We need to identify topics that deserve study and find ways to get the testing done.
We sincerely appreciate the increased activity in the comments section and hope to make this blog more of a two-way street. Let’s use this forum to develop a things-to-do-list for the next generation.
PS: Anyone have drawings of the finger gears used in the famous Hulet self-unloaders? I want to reference them in my upcoming Fall Technical Meeting paper and would prefer to show an actual drawing rather than a sketch based upon my memory of making spare parts back in 1981.
PPS: A completed word search is attached; hope you enjoyed hunting for those (50) gear terms.