Based on the theory of rack-gear equal-tangential conjugate generating

the construction of numerical model of tooth surface and ease-off surface of gears was presented. Through analysis on the tooth surface meshing information of ease-off surface implication

the contact path

transmission errors and falls of contact line were obtained. Combining the ease-off simulation of tooth surface and the non-linear element coupling gear stiffness analysis

the computational method on time-varying meshing stiffness

loaded transmission errors for the modified tooth surface was presented. The computation was done by traversing the sequence contact lines according to the contact path

then the tooth meshing stiffness

loaded transmission errors and load distribution map were obtained. Two examples on topological tooth surface for symmetrical and bias modification of the 2-order paraboloid were acquired

and a series of results for the tooth meshing stiffness

loaded transmission errors and load distribution map under varied loads were gained. Results showed that the varied effects of tooth meshing stiffness weakened obviously with the increasing loads

and the fluctuation of loaded transmission errors was closely related to meshing stiffness and modification gradient of tooth surface. The bias modification was better than the symmetrical one in the performance of meshing stiffness

loaded transmission errors and load distribution.