A new type of gear anti-backlash drive mechanism is put forward

in view of the manufacturing difficulty and the high cost of the traditional anti-backlash mechanism. A pair of worm gears which are against each other and the double gears are used to eliminate the back lash. The dynamics model of the mechanism is established by the method of lumped mass

and the numerical solution for the model is worked out by fourth-order Runge-Kutta. Then the nonlinear dynamic characteristics of the system are simulated and analyzed. The results show that the dynamic characteristics of the mechanism is good when the back lash is eliminated

the vibration attenuation time can be shorten by the increasing meshing damping of the system

and the vibration amplitude of the system can be reduced by the improving average meshing stiffness.