Influences of spline assembly methods on nonlinear characteristics of spline–gear system

As a connector, the spline is widely applied in gear transmission systems. In transmitting torque, the load and deformation of the spline are affected by the applied assembly method, and this effect leads a change in the time-varying meshing stiffness (TVMS) of the gear pair. Consequently, the nonlinear characteristics and vibration performance of the whole system can be affected. In this study, the TVMS of gear systems that use two different spline assembly methods, namely, the-side-fit and the-major-diameter-fit, is predicted by finite element contact analysis. Subsequently, the nonlinear dynamic model of the spline–gear system is established and its accuracy is verified through a vehicle vibration experiment. The numerical results reveal that the system assembled through the-side-fit and without spline exhibits a diverse range of periodic, sub-harmonic, and chaotic behaviours at high speed, whereas no bifurcation is observed through the-major-diameter-fit. As the magnitude of interference increases in the-major-diameter-fit, the dynamic transmission error decreases. Therefore, different assembly methods can affect the nonlinear characteristic. Moreover different magnitudes of interference in the-major-diameter-fit also have effects on the nonlinear characteristics and vibration performance of spline–gear systems.