基于正交设计法的柴油机主轴承润滑性能优化

Lubrication characteristics optimization for main bearing of diesel engine based on orthogonal design methodology

为对主轴承结构参数和润滑油参数进行优化匹配,根据动载滑动轴承弹性流体动力润滑模型,结合AVL Excite软件对CA4D32柴油机主轴承进行多体动力学与弹性流体动力学耦合仿真.精确选取标定工况下影响各主轴承润滑性能的轴承宽度、供油压力、供油温度、润滑油类型、径向间隙、轴瓦油槽方向、轴颈油孔位置等关键因素,以最小油膜厚度为优化目标,基于正交设计法,确定各主轴承润滑性能最优参数组合,并对该参数组合进行仿真验证.结果表明:各主轴承最小油膜厚度增大9.1%～32.1%,一个循环内最小油膜厚度明显增大且其波动趋于平缓;各主轴承总摩擦功率损失显著降低.

To make structural parameters of engine main bearing and parameters of lubricating oil matching and optimization,according to elastohydrodynamic lubrication model of dynamically loaded bearing,coupling simulations between multibody dynamics and elastohydrodynamics were conducted to CA4D32 diesel engine main bearing by employing AVL Excite software.Bearing width,oil supply pressure, oil temperature,oil type,radial clearance,groove direction in shell and bore position in journal were chosen precisely as key influencing factors under rated working condition,and minimum oil film thickness（MOFT） was chosen as optimized objective.Based on orthogonal design methodology,the optimal parameters combination was determined.Simulation results show that MOFT of main bearings increases by 9.1%—32.1%,MOFT in one working cycle increases obviously and the fluctuation of MOFT tends to be gentle.In addition,the total friction loss power is significantly reduced compared with original design.