The dynamic contact finite element models of standard involute gear and modification gear are established in the software of ANSYS. Based on the explicit dynamic formula of ANSYS/LS-DYNA

the dynamic contact analysis of gears under different rotation speeds is completed. It deduces that the elastic deformation of standard involute gear teeth leads to bigger meshing-in impact and it gets obviously better after tooth modification. The dynamic contact emulation method of gear transmission has important theory significance to ascertaining a gear modification amounts and diminishing the gear dynamic load.