Torsional Stability of a Face-Gear Drive System

Abstract

This paper establishes a structural dynamics model for torsional vibration of gearboxes containing a face-gear drive by considering flexibilities of gear teeth and transmission shafts. This model includes the time-varying gear mesh stiffness resulting from the unique face-gear meshing kinematics and nonunity contact ratio. The face-gear mesh-induced parametric instability phenomena are explored numerically via Floquet theory for various shaft characteristics and system inertia distributions. In addition, Tregold's approximation is employed for face-gear contact ratio calculations to avoid complex numerical computations. For design purposes, a perturbation technique is utilized to analytically predict the parametric instability boundaries for the cases with small time-varying components.