Due to the contact stress during gear meshing, contact deformation will occur. The contact deformation δcb can be calculated according to the formula

The total deformation δj of the meshing point can be obtained by adding the above three deformations

The ratio of meshing force and total deformation is the meshing stiffness of the meshing point

For the whole meshing period, n meshing points are selected, and the meshing stiffness at these meshing points is obtained respectively according to the above method, so as to obtain the time-varying meshing stiffness of tooth pairs.