本文主要探討目標為齒輪組之動態響應分析與齒輪故障對系統動態特性的影響。研究方法為使用集中質量法將齒輪系統以質量,嚙合剛度彈簧、阻尼建立齒輪動態分析的模型,並使用有限元素軟體ANSYS建立無缺陷齒輪組與齒根有裂痕齒輪組的模型並分析齒輪接觸時的變形與受力,計算隨不同嚙合位置改變的嚙合剛度,將兩種模型的嚙合剛度代入運動方程式,並以數值方法龍格-庫塔法求解齒輪的動態響應,分析兩種齒輪組在各種不同轉速下的特性,最後以頻譜分析與均方根找出的齒根有裂痕的故障特徵。The purpose of this research is to investigate the dynamic characteristics of a spur gear pair and to study the effects of tooth crack on the dynamic response. The gear dynamic model is developed by a lumped parameter method for the vibration response. The mesh stiffness between two gears is calculated by using a finite element software – ANSYS. Then, the equations of motion are solved by using Runge-Kutta method. The features of dynamic signals for the crack in a tooth are found.