Bearing contact analysis of the involute spur planetary gear train

Abstract

The goal of this study is to determine the dimensions and orientations of instant contact ellipses of gear surfaces in the meshing of the planetary gear train in order to recommend the proper amount of the crowning radii. The mathematical model for the surface profiles of the simple planetary gear train with the crowned planet gear is developed to simulate gear-meshing conditions and obtain the contact points. Principal curvatures and directions of the planetary gear train are derived and investigated based on the theory of gearing. The dimensions and orientations of the contact ellipses of the planetary gear train due to the assembly errors of different kinds of axial misalignments in different crowning radii can further be developed from the principal curvatures and directions of gear surfaces. Examples are presented to illustrate the above-mentioned investigations.