Influences of design parameters on meshing stiffness of herringbone gear with high contact ratio

In order to help to design herringbone gear system with high contact ratio, a knowledg discovery method was proposed, which combined fuzzy mathmatic with rough sets theory (RST). At first, a fuzzy clustering method was applied on the simulation results and helped to acquire the classification of the tooth meshing stiffness. Then, the design decision rules were deduced by discretization of simulation parameters, the reduction of attributes and values which were based on the RST. And these rules show the relationship among the meshing stiffness and design factors. At last, the illustration of three new samples demonstrates the validity of this new method in application of knowledge discovery of simulation data.