Most of the large open gear sets for mining industry are designed according to ANSI/AGMA 6014-A06 and
ANSI/AGMA 2001-D04.
Basically, customer specifications and AGMA service factor ratings both depend on design of the pinion
(including material selection and heat treatment), as well as the finishing process of the teeth (to achieve the
designed geometry).
Today, with the increase of mesh load, design and manufacture of gearing to meet specifications and ratings
becomes even more challenging.
In complement to the traditional mechanical properties (such as hardness or yield strength), elastic and
thermal behaviors and their influence on transmission accuracy have to be taken into account from the design
stage, especially for large open gears (over 5 m in diameter).
That implies a rise of cutting quality selected at the design stage, and of course and consequently,
improvements in manufacturing and quality control, as normal processes that were used successfully for
years are nowadays reaching their limits.
This paper, using detailed examples, introduces these mandatory improvements in design, manufacturing
and inspections, starting from material elaboration to final machining, and focus on today’s large and powerful
gearing.