湿式离合器接合过程摩擦振颤机理研究

Friction-induced vibration of wet clutches

通过建立4自由度动力学模型,研究了湿式离合器在接合过程中的摩擦振颤问题。基于稳态的非线性LuGre摩擦模型,通过特征值方法进行稳定性分析,并基于MATLAB/Simulink对该动力学模型进行数值仿真。结果表明,摩擦因数随相对滑动速度的负梯度变化及接触界面的压力波动是摩擦振颤发生的主要原因,在不稳定状态下,静、动摩擦因数之差越大,压力波动频率越接近不稳定模态固有频率,振颤越强烈;同时阻力矩激励也会对摩擦振颤产生与压力波动相同的效果。

The characteristics of friction-induced vibration of wet clutches were investigated based on a four-DOF dynamic model.The steady-state nonlinear LuGre friction model was employed.Stability analysis was performed by applying the eigenvalue method,the numerical simulation for the dynamic model was conducted with MATLAB /Simulink. The results demonstrated that the negatively sloped variation of friction coefficient with changes of relative sliding velocity and the fluctuation of interface pressure are the causes of clutch judder;under unsteady state,the larger the difference between static friction coefficient and kinetic one,the smaller the difference between the pressure fluctuation frequencies and unsteady modal frequencies,and the stronger the clutch judder;the resistance moment excitation has a similar effect to that of interface pressure fluctuation on clutch judder.