ABSTRACT
The design and operation of gears is more complicated than almost any of the other common mechanical devices. They incorporate cantilever fatigue loading of the teeth similar to a beam in bending, Hertzian fatigue loading of the contact surfaces similar to a rolling element bearing, plus the lubrication demands of a pair of surfaces that involve both sliding and rolling. They are incredibly complex, and their failure analysis isn’t for the faint of heart or for those whose primary athletic ability lies in jumping to conclusions. From the basic principles covered in the earlier chapters and careful inspection of the failed components, determining the source of most gear failures isn’t terribly difficult. However, to help in their understanding, the first part of this chapter explains some of the more important details of gear design and function.
