Quasi-Static and Dynamic Analysis of Narrow-Faced Helical Gears With Profile and Lead Modifications

Abstract

A systematic analysis of the influence of tooth shape modifications on the dynamic behavior of single stage narrow-faced helical gears is proposed. Calculations are performed using a 3D model with 36 degrees of freedom including torsional, flexural and axial generalized displacements of the gear-shaft-bearing system. Two approximate equations giving the normalized static transmission error STE and load factor RF are deduced. It is shown that, for a given gear set, there exists a unique representation of STE and RF valid over a large range of profile, lead modification amplitudes and transmitted loads. The role of the extent of the profile relief (long, short and intermediate) and the shape of lead modifications (parabolic, elliptic crowning, linear chamfers) is discussed. The paper is concluded by the analysis of the dynamic transmission error of a gear set with various tooth shape modifications selected from static considerations.