Abstract: The pure rolling model, equal turning angle model and bisection model for the design of eccentric involutes gears transmission have model error. On account of the geometrical relationship of eccentric involutes gears transmission, the differential equation of eccentric involutes gears transmission is established. The differential model for the design of eccentric involutes gears transmission is presented. The relationship between maximum transmission ratio and offset coefficient is analyzed. Some analysis and design parameters are fitted by polynomial. The analysis and design can be completed fast and accurately by using polynomial fitting formals, so the process of analysis and design are simplified. The differential model not has model error. Solving the differential equation has rounding error.

Key words: Curve fitting, Eccentric involutes gear, Gear transmission, Non-circular gear