多片离合器摩擦对偶片屈曲变形的分析与验证

Analysis and Verification on Friction Discs Buckling in Multi-disc Clutch

本文旨在研究了离合器摩擦对偶片花键处受周向转矩作用发生屈曲变形的过程。建立了对偶片屈曲变形时各阶临界屈曲弯矩的计算模型,定量分析了厚度等结构参数对摩擦对偶片各阶临界屈曲弯矩的影响,并通过离合器低速低载荷工况下的摩滑磨损实验验证了对偶片屈曲变形模型的计算结果。结果表明,在对偶片发生因大温度梯度导致的热翘曲前,引起摩擦界面局部接触压力显著升高的主要原因是花键处因机械转矩作用而产生的屈曲变形,它引起周向压力扰动而导致热弹性失稳。对于工程常用摩擦对偶片,厚度与节圆半径比值大于0.015 5时可明显提高对偶片抗机械扭转变形的能力,从而增大摩擦界面接触区,降低接触区比压,改善摩擦状态。

This paper aims to study the bucking process of splines in the outer edge of clutch friction disks under the action of circumferential torque. Specifically a calculation model is set up for each order of critical bucking moment when friction disks buckle,the effects of structural parameters like thickness on each order of critical buckling moment are quantitatively analyzed,and the calculation results of friction disks buckling model are verified by the friction and wear tests of clutch under low speed low load conditions. The results show that before the thermal warping of friction disks caused by large temperature gradient occurs,the action of torque make splines buckle,leading to significant rise in local contact pressure between friction disks and resulting in circumferential pressure fluctuation and thermo-elastic instability. For commonly used friction disks in engineering,a ratio of thickness over pitch circle radius larger than 0. 0155 can significantly enhance the twist deformation resistance of friction disks,and hence increase the contact area of friction interface,lower its specific pressure and improve friction condition.