On the lumped parameter modeling of worm gear mechanisms: Experimental validation and insights

A non-linear 8-DOF model capable of capturing the fundamentals of the worm gear dynamics has been developed. The model incorporates external excitations, non-linear time-varying meshing stiffness, and components related to friction phenomena. This study is dedicated to a thorough exposition of the lumped parameter model, accompanied by a comprehensive examination of its equations and an analysis of the impact of diverse contributions. The procedure employed to determine the meshing stiffness is further investigated using a finite element methodology, as it is a crucial input for the dynamic model. Furthermore, a comprehensive description of the experimental campaign conducted to validate the model is presented, enabling an in-depth analysis of the impact of speed and torque on the overall dynamics of worm gear mechanisms. In order to assess the capability of the model to accurately capture the effects of these two parameters, a comparison is made between the numerical results, specifically the bearing forces and transmission errors, and the experimental data. These comparisons facilitate the validation of the model.