On the dynamic simulation of eccentricity errors in planetary gears

Eccentricity errors are incorporated into a planetary gear lumped parameter model in which deflections, errors and gear geometry are coupled. In the presence of errors, rigid-body positions and motions are perturbed leading to initial separations between tooth flanks and inertial excitations caused by unsteady rotational speeds. The equations of motion are solved by combining a time-step scheme, a contact algorithm and a fixed-point method, which make it possible to determine and use mesh instantaneous characteristics in the calculations of tooth loads. A number of quasi-static and dynamic results are presented which show that eccentricities can be highly influential on planetary gear dynamic behaviour. Finally, the interest of floating members in equalizing planet dynamic loading is demonstrated and commented upon.