Influence of tip relief in spur gears dynamic using multibody models with movable teeth

Abstract Tip relief modifications are a common design feature used in industrial practice to reduce dynamic tooth loading, noise, vibrations and wear in high-performance gears. This paper presents a novel implementation of a specific multibody model to include the effect of tip relief micro-modification on spur gears. The model considers every tooth attached to the wheel hub with a revolute joint and an equivalent torsion spring. A penalty formulation is adopted to solve the teeth contact (2D). The proposed methodology offers a trade-off between the accuracy of an equivalent finite element method model and the advantage of reducing the degrees of freedom allowing for fast dynamic simulations. Moreover, there is no need to preliminary predict mesh stiffness or static transmission error as a source of excitation for dynamic simulation, because these are direct outputs of the model simulation given the modified tooth geometry. Model validation is done comparing numerical results with experimental data taken from literature. The effects of geometry modification are studied both in quasi-static and dynamic conditions. Finally, the model has adopted to assess the off-design performance of spur gears.