曲轴—轴承是不可分割的系统,这个系统一旦运转起来以后,它的各种机械行为必然是同时发生并相互影响的。基于这种理念,提出的求解曲轴—轴承轴心轨迹的方法是:联立求解曲轴动力学方程和轴承润滑方程,得到作用于轴承上的载荷和曲轴动力学响应(轴心轨迹),再通过进一步地润滑分析得到轴承的摩擦学特性。与静力学方法获得两维轴心轨迹相比,动力学方法分析计算得到的曲轴轴心轨迹是三维的,并可以得到曲轴轴心轴向运动轨迹。此外,两种方法求得的轴承最小油膜厚度和最大油膜压力也不相同。导致不同计算结果的原因是由于曲轴系统动力学效应引起的。
The bearings in a crankshaft-beating system of an internal combustion engine, which are typical ones applied by varying load, are studied in the idea that crankshaft and bearings are in one inseparable system and various mechanical behaviors happen simultaneously and influence each other when the machine is working. Based on this idea, a method to obtain the trajectory of the crankshaft journal center is put forward. First the dynamic control equations of crankshaft and the Reynolds' equation of bearings a re solved simultaneously to obtain the dynamic response of the crankshaft and the applying force on the bearings. And then, the tribological properties of the bearings are obtained through lubrication analysis. The trajectories of crankshaft journal center are three-dimensional and the axial trajectories can be obtained by the dynamic method while the two-dimensional trajectories can be only calculated by the static method. The obvious changes happen in the maximum pressure and minimum thickness ofoil film in the bearings for the two different methods because the dynamic effect of the crankshaft-bearing system is considered in the dynamic method presented.