某型柴油机活塞销轴承磨损分析及表面型线设计

针对某型柴油机活塞销轴承初始设计方案在试验中出现的磨损问题，开展了活塞换热分析及活塞温度场仿真与试验对标。在此基础上进行热机耦合变形分析，发现活塞销轴承变形不协调是导致此类问题的主要原因。针对活塞销孔轴承进行热机状态型线匹配分析，开展了活塞销孔轴承热机耦合状态下的型线优化设计，通过仿真及试验验证了该型线优化方案的有效性。分析了桶形型线、指数型线及超椭圆型线对连杆小头衬套轴承载荷分布状态的影响，3种型线对比结果表明，指数型线和超椭圆型线可有效地改善连杆小头轴承载荷分布状态。

Profile Design and Seizure Analysis of Piston Pin Bearing of a Diesel Engine

For the seizure failure of piston pin bearing in the preliminary structural design, the heat transfer of piston is simulated and its temperature field is calibrated, and the thermo-mechanical deformation of piston at state is analyzed. The analytic results show that the non-compatible deformation of piston pin bearing is main reason leading to wear. Accordingly, the profile matching of piston pin boss bearing under thermo-mechanical condition is presented. On this basis, the profile of piston pin boss bearing is optimized, and the optimized profile is validated by simulation and engine test. The barrel-shaped, exponential and hyperelliptic profiles of the connecting rod small end bearing are compared to investigate the influences of those profiles on the load distribution of the bush. Results show that exponential and hyperelliptic profiles are more suitable for improving the load distribution of the connecting rod small end bearing.