Analysis And Research Of Lubrication System In China-Ⅴ Diesel Engine Independent Development

Lubrication system is one of significant systems of internal combustion engine.Lubrication capability has a direct effect on engine’s reliability, dynamic property,economic property and emission property. Therefore, analysis and optimization onlubrication system has a great engineering practical importance and theory value.This paper took the lubrication system of four-cylinder China-Ⅴ diesel engineduring independent development as research object, and carried out theory analysisand optimized calculation. Firstly, viscous fluid elementary equation satisfied withlubrication oil flow was analyzed, including mass-conservation equation,Navier-Stokes equation, and energy-conservation equation. Secondly, the constructionformation, lubrication oil-way and main components were analyzed in details. Themath models of components were established based on the theory of the viscous fluid,and1-dimension system model was built for calculation. The model’s inputparameters were exact through proving of the preliminary test, and the model couldreflect variation tendency of main gallery lubrication oil pressure. The dimensions oflubrication oil-way and main bearings were designed optimized after analysis ofcalculation result.Then, Orthogonal array (OA) was used to conduct Design of Experiment (DOE)for8main lubrication oil-way dimensions, and64groups of dimensions combinationwere acquired. The approximation model was built with the method of Radial BasisFunction Neural Network (RBFNN). Optimization of lubrication oil-way dimensionsbased on the approximation model was conducted using Multi-Island GeneticAlgorithm (MIGA). The lubrication oil-way dimensions were designed reasonably.And then the main bearings’ dimensions were optimized based on optimizedlubrication oil-way. Under the condition of reliable lubrication on the main bearings,the lubrication oil consumption rate and friction power loss were reduced. The loss offriction power was reduced by16.2%over the whole speed range.The test results of components and parts including oil filter and oil cooler bothshow that their pressure drop and flow rate curve are fitting with input boundary data.This guarantees the accuracy of calculation result. Oil pump pressure character testdemonstrates that the maximum deviation of experiment value and calculated value oflubrication oil supply from oil pump doesn’t exceed by8%. The simulation result istrustworthy. China-Ⅴ diesel engine’s prototype was trial-manufactured, and preliminary workbench test was conducted. The test result shows that the maximumdeviation of test value and calculation value of main gallery oil pressure doesn’texceed by6%under different speeds. The system model is reasonable basically andcan be used to guide the design of lubrication system. In addition, the power is closely110kW at rated speed3200r/min. Overall, the target of engine economic property anddynamic property has basically achieved development target.