Abstract: Based on the existing references， considering the accurate modeling of the tooth， this paper presented a correction method by simplifying the gear tooth as a cantilever beam on the root circle. Comparing with the results from references and finite element method， the error reasons of different methods were presented and the validity of this method was proved. This method can avoid judging the number of tooth and improve the generality of the potential energy method when calculating the timevarying mesh stiffness. The results provide theoretical basis for the meshing dynamic analysis of spur gears.

Key words: spur gear, timevarying mesh stiffness, improved energy method, finite element, practical transition curve