Transmission characteristics of injection moulded polymer spur gears: experimental and numerical evaluation

Abstract

The transmission characteristics of gears are the functional requirement when the gears are used for precision motion applications such as robotics, actuators of satellite launchers, etc. In the present study, a test rig has been developed to simulate steel-polymer gear mesh and measured static transmission errors at various roll angles for different loading conditions. Multi tooth gear pair was considered and finite element method was adopted to evaluate static transmission error and gear mesh stiffness at different loads. From the evaluated path of contact, premature and extended contacts were observed due to less stiffness of polymer gear tooth. The results obtained through numerical simulations were compared with experimental results and found to be in good agreement. The difference between polymer and steel gear tooth stiffness, contributes to the non-uniform gear mesh stiffness/static transmission error both at single and double tooth contact regions. The roll angle and static transmission error of gear pair were found to increase with load.