Modeling Axial Vibrations in Herringbone Gears

Abstract

Abstract This paper addresses the axial vibrations of herringbone gears. Theoretically, herringbone gears balance their axial loads due to their symmetry; however, in practice, they present high vibrations. The reasons are manufacturing deviations such as lead angle errors, pitch error differences between each side of the gear, misalignment between pinion and gear axes, etc. These errors can be represented as an error function of sinusoidal form acting as forced vibrations over the teeth. Although axial and lateral motions of a gear pair are generally coupled, the symmetric geometry of herringbone gears makes possible to analyze the axial and lateral stiffness as uncoupled functions. It is viable then to represent the axial motion as a single degree of freedom model. The effect of each parameter of the error function is analyze individually in order to determine which has the greater effect in the system. Results are compared to field data showing good agreement.