Simplified dynamic modeling methodology for parallel shaft gear transmission system

Complex gear transmission usually consists of both parallel shaft and planetary gear transmission which will lead to large number of degrees of freedom and high computing cost for computers. When focusing on dynamics of planetary gear transmission, it is a good way to simplify the dynamic model of parallel shaft gear transmission for more effective calculation with less accuracy loss. In previous papers, the existing simplified modelling methodologies prefer to eliminate all gear pairs, fail to consider the dynamic model changes caused by mechanical structure and the simplified model of the gearbox housing. In this study, a simplified dynamic modelling methodology for parallel shaft gear transmission system consists of n gear meshing pairs is proposed to correctly predict the dynamic characteristics during the product design phase with less computational cost. Based on local simplified equivalent method, parameters of components in parallel gear system such as mass, stiffness, and moment of inertia are equivalent to motor shaft and connecting shaft to other transmission stages. One gear meshing pair was reserved in simplified model for describing nonlinear dynamic factors such as time-variant meshing stiffness, backlash in meshing pairs, friction on gear meshing surface. The vibration energy values of eliminated gear pairs transmitting on reserved gear pair are calculated based on mechanical system vibration transmission theory. Based on agglutination method, gearbox housing was simplified into discrete nodes to make the continuum gearbox housing available for centralized parameter modelling. The modelling method in this study is validated by experiment in case study, and the results exhibit that this method is quite accurate and helpful in dynamic modelling for complex parallel gear transmission system.