In essence, stiffness excitation is a kind of parametric excitation based on the number of teeth. In the process of meshing, the elastic deformation of gear teeth changes periodically due to the periodic alternation of single and double teeth with time and the continuous movement of meshing position on the meshing line. This periodic elastic change of gear teeth is called time-varying meshing stiffness.
The time-varying meshing stiffness is one of the main excitation factors in the gear transmission system, and it is also an important parameter that affects the dynamic characteristics of the gear system. An effective calculation method of the time-varying meshing stiffness is very important to fully understand the dynamic characteristics of the gear system The deflection of gear body is ignored.
Under this assumption, since the number of teeth of the standard involuteto be considered is less than 42, the calculation equations of Hertz stiffness, bending stiffness, shear stiffness and axial compression stiffness are given only when the root circle diameter is less than the base circle diameter.