湿式双离合变速器动力学特性与失效机理

Study on Dynamic Characteristics and Failure Mechanism of Wet Dual Clutch Transmission

摘要:

针对某6挡变速湿式双离合变速箱失效问题展开分析，发现扭转减振器中的树脂滑块碎裂是导致车辆失去动力的主要原因。为分析失效原因，首先进行了车辆启动及全油门加速试验，发现冷冻启动（发动机温度-2~5 ℃）时扭转减振器承受的冲击力矩值最大为928 N·m，加速工况下最大冲击力矩多发生在换挡和低档位全油门加速过程中；其次，建立了驱传动系统扭振动力学模型，进行动力学特性分析，发现系统一档未接合状态的第二阶固有频率（11.51 Hz）与试验中启动工况峰值频率（8~13 Hz）较为接近，系统产生共振，滑块容易损坏。研究表明，车辆启动过程中较大的瞬时冲击力矩以及行驶过程中产生的系统共振，是导致滑块疲劳失效的主要原因。

Abstract:

The failure of a 6-speed wet dual clutch transmission is analyzed， and it is found that the fracture of resin slider in torsional shock absorber is the main reason for the vehicle losing power. In order to analyze the failure condition and failure mechanism， vehicle starting and full throttle acceleration tests were carried out. It was found that the maximum impact moment of the torsional shock absorber was 928N·m when the engine temperature was -2~5℃， and most of the maximum impact moment occurred in gear shifting and full throttle acceleration in low gear condition. To explore the failure mechanism， a torsional vibration mechanical model of drive system was established， and the inherent characteristics were analyzed. The results show that the second natural frequency （11.51Hz） of the first gear unengaged state of the system is close to the peak frequency （8-13Hz） of the starting condition in the test， and the resonance slider is easy to be damaged. The results show that the large instantaneous impact mo ment and the system resonance during the starting process are the main reasons for the fatigue failure of the slider.