Axle Gear Mesh Force Prediction, Correlation and Reduction

Hypoid gear whine, also called axle whine, is one of the popular chronic NVH issues in the vehicle and driveline development. Axle whine was found under various driving conditions such as acceleration, deceleration and coast in both light and heavy torque applications. Dynamic mesh force produces vibration energy that passes through vehicle frame/body to generate a tuning sound inside vehicle cabin. Most axle whine was found as structure-born noise and its response frequency range was often from 200 - 800 Hz. Up to now, many researches have been contributed to hypoid gear mesh modeling, which delivered both linear and nonlinear modeling techniques for gear train system simulation. With applying different gear mesh modeling techniques, this study focused on prediction, correlation and reduction of dynamic gear meshing force of a driveline system. Specifically, the calculated meshing force of the nonlinear gear mesh model was compared to that of the linear mesh model using a previously correlated driveline model. A good correlation result was found. Some important issues such as effects of driveshaft bending modes, ring gear stiffness and torsional damper on the mesh force were also investigated. The research showed a promising future in enabling upfront CAE analysis by applying the nonlinear gear mesh model to minimize the axle noise.