Contact analysis for noncircular gears

Abstract

Few studies on the performance of noncircular gears meshing have been produced. Due to their complex geometry and to the lack of standard design procedures, the evaluation of noncircular gear contact and strength is up to researchers and is based both on traditional gear theory and modern computerized methods. The paper presents an investigation of noncircular gears meshing conditions, focused on the static tooth contact and FEM analysis, related to variations in gear tooth geometry. The tooth contact analysis is developed in the AutoCAD environment and describes the paths of contact area and distribution for two gear pairs, generated by the rolling of the rack cutter along the noncircular centrode and along the circular centrode that locally approximates the noncircular centrode, respectively. The FEM analysis is developed by Inventor facilities and enables the evaluation and comparison of the gear tooth stresses and displacements for noncircular gears with various tooth profiles. The results are important to complete the existing noncircular gear data base in an attempt to improve the gear design procedure.