A Theoretical Study of the Effect of Pinion Offset on the Dynamics of Hypoid Geared Rotor System

Abstract

A new 3-dimensional coupled rotational-translational vibratory model of a high-speed loaded hypoid geared rotor system has been formulated to analyze the dynamic effect of pinion offset. This model includes the effective shaft and bearing flexibilities, and gear mesh induced dynamic couplings of the lateral, axial, torsional and rotational motions. The proposed formulation is also capable of simulating drive and coast operating cases. Its effective mesh point and line of action are assumed stationary for a given steady-state condition, and they are defined by the theoretical pitch point vector and corresponding normal vector at the point of contact respectively. The proposed analytical model is applied here to compute the modal response functions of a typical automotive drivetrain design for a selected range of pinion offset. The calculations revealed interesting frequency-dependent effects of pinion offset on the generation of dynamic mesh force and bearing reaction loads.