| Basic demands for lubrication system in traditional designing process of internal combustion engine (ICE) is to supply sufficient lubricant to friction parts and to work without failure in order to make sure that ICE can operate credibly. However, the development of modern society have put forward more new demands on the design of ICE' lubrication system. Requirements from environmental protection and energy saving area such as emission control regulations should be resolved when traditional one continues to be fulfilled and improved. On environmental protection, results from experimental study show that there's strong connection between the formation of particle emission and oil consumption from lubrication system. In the energy saving area, there's experimental study which show that the oil fee consumed by a mean ICE in one year is about 4 percent of the fuel fee. And same time, there's potential to reduce fuel consumption within pump's driving power in lubrication system. Traditional method with experiences and research in single operating condition can not satisfy the demands of modern design of ICE's lubrication system. There should have a more perfect theory used to review the operating property of ICE's lubrication system. Several key points in the process of network analyzing with lubrication system were discussed in this paper. Combining with a model engine, a improved network analysis method was used to analyze the property of lubrication system in multiple operating conditions.Several kinds of simplified methods for flow characteristic of oil in bearing are described firstly in this paper. And a new idea was also put forward. By analyzing with an example, all those methods have been compared with the method by hydrodynamic lubricating analysis. A research on the lubrication of ICE's main bearing considering thermal deformation effects are presented combining with a model engine's main bearing. Through comparing the results from analysis by with and without considering thermal deformation effects, effects from thermal deformation factors on the thermal hydrodynamic analysis of ICE's main bearing were discussed. An experimental study on the temperature of journal bearing during start-up and operation process with variation of working condition was also carried out in this paper.Combining with the true state of oil that flowing in lubrication system's pipe, a special equipment used to test the character of oil flowing in pipe was constructed. With the results from test, several measures that currently used to describe the character of oil flowing in pipe were analyzed by comparing. And effects on the character of oil flowing in pipe from many factors, such as diameter of pipe, length of pipe and oil temperature, were studied by this test.Working characters of oil pump, oil filter and cooler were investigated separately by experiments. And these characters were modeled by using the function of modeling nonlinearly of BP neural net combining with the results from test. How to choose learning samples in the process of modeling with neural network was discussed here and was also examined by the test.With theories of conversation of energy and mass, relationships of drop-flowing on each net node were established for network model of sample engine's lubrication system. Optimization method based on least-squares algorithm was put forwarded to solve the nonlinearly equations that constructed in the network analysis of lubrication system. And a simulation analysis on model engine was presented to review emphatically the distributions of oil pressure and flowing of lubrication system in ICE's operation conditions.In the end of this paper, application of network simulation method on lubrication system was examined combining with the experimental research under multiple operating condition of ICE. Running-in tests and indicator diagram tests under multiple operating condition of ICE. were presented, and all results of these tests have been analyzed. Calculations and analysis of bearing loads under multiple operating condition of ICE were done with the results of indicator diagram tests. Simplified methods for flow characteristic of oil in bearing were applied in the process of network analysis of lubrication system. Through comparing with test results, influences of these simplified methods on the selection of oil pump in the process of ICE's lubrication system design process were analyzed. Effects on the pressure property of main oil gallery from those factors such as rotate speed, load and oil temperature were examined emphatically under multiple operating condition of ICE. And oil consumption under multiple operating condition of ICE was also discussed here.Innovative points of this paper can be summarized as following. Several kinds of simplified methods used to describe flow characteristic of oil in bearing are compared firstly. And influences of these simplified methods on the selection of oil pump in the design process of ICE's lubrication system were investigated. Research on the lubrication of ICE's main bearing considering thermal deformation effects are presented. A special equipment used to test the character of oil flowing in pipe was constructed. Several measures that currently used to describe the character of oil flowing in pipe were analyzed by comparing test results. Working characters of oil pump, oil filter and cooler were modeled by using the function of modeling nonlinearly of BP neural net. An efficient way to calculate bearing loads by union application of mechanism module in Pro/E and Matlab software was introduced. Optimization method based on least-squares algorithm was put forwarded to solve the nonlinearly equations that constructed in the network analysis of lubrication system. Network analysis on property of lubrication system of sample engine was carried out under both full load condition and part load condition. And by the experimental study on the pressure property of main oil gallery, feasibility of improved network method was testified.
|
PDF Full Text Request