非道路柴油机主油道压力优化研究

Main Channel Pressure Optimization of Off-road Diesel Engine

某车用柴油机改为非道路使用后,额定功率转速从3600 r/min降为2400 r/min,这对原机油泵提出了更高要求。应用AMESim软件建立柴油机润滑系统一维仿真模型,仿真分析发现柴油机转速降低后,机油泵主油道压力已不能满足新的工况要求。对该机油泵的额定流量和泄压阀开启压力进行分析和优化,在不改变其他结构参数的基础上,将机油泵最大额定流量和开启压力分别从35.3 L/min和600 kPa调整到50 L/min和500 kPa。仿真分析表明,优化后主油道压力能满足柴油机相关部件润滑要求,且最小油膜厚度满足设计要求;同时还发现机油滤清器和机油冷却器阻力损失越大,主油道压力降低越明显,机油泵出口压力随机油滤清器和冷却器的总阻力升高而变大。

After the vehicle diesel engine is converted to non-road use,the rated power speed is decreased from 3600 r/min to 2400 r/min,which puts forward higher requirements for the original oil pump.The one-dimensional simulation model of diesel engine lubrication system was built by AMESim software.The simulation analysis shows that the main oil pressure of the oil pump can not meet the requirements of the new working condition after the rated power speed of the diesel engine is reduced.The rated flow rate of the oil pump and the opening pressure of the relief valve were analyzed and optimized.The maximum rated flow rate and the opening pressure of the oil pump were adjusted from 35.3 L/min and 600 kPa to 50 L/min and 500 kPa without changing other structural parameters.The simulation analysis shows that after optimization,t he main oil channel pressure can meet the lubrication requirements of the relevant parts of diesel engine,and the minimum oil film thickness can meet the design requirements.Meanwhile,it is found that the greater of the resistance loss of the oil filter and cooler,the more obvious the decrease of main oil channel pressure,and the outlet pressure of oil pump is increased with the increase of the total resistance of the oil filter and cooler.