Identification of Flexspline Parameters Affecting the Harmonic Drive Lost Motion Using the Global Sensitivity Analysis

Abstract

The aim of this research was to find out the specific geometrical parameters of the harmonic drive with the greatest impact on its lost motion. Harmonic drive units are widely used in production automation, robotics and automated manufacturing systems. Virtual model of Harmonic Drive was examined using the finite element method. The analyses were performed with considering the real test conditions of high precision gearboxes with a lost motion value of 4 % of the nominal output torque. The analyses' results were then used to develop a unique approach to obtain a functional relationship between the input parameters defining the shape of the flexspline and the harmonic drive lost motion value. Subsequently, the global sensitivity analysis was performed to determine the degree of influence of the selected flexspline parameters on the harmonic drive kinematic accuracy.