The influence of tooth pitting on the mesh stiffness of a pair of external spur gears

Time-varying mesh stiffness is one of the main internal excitations of gear dynamics. With the growth of gear tooth fault, like pitting, cracking and spalling, the mesh stiffness amplitude changes and consequently the dynamic properties of the gear system change. This study is devoted to deriving equations of the mesh stiffness of a pair of external spur gears with tooth pitting. Different pitting severity levels are modeled. The influence of tooth pitting on the gear mesh stiffness is investigated. The relationship between pitting severity and mesh stiffness is established. The proposed method is validated to be effective in mesh stiffness evaluation by comparing with a finite element model.