Analysis And Research On Abnormal Wear Of Engine Connecting Rod Bearing

The engine is the core component of the structure of the car,the quality of the engine directly affects the vehicle's fuel consumption level,safety and comfort.Sliding bearing is the key part in the structure of automobile engine,which is an important friction pair with the crankshaft main shaft diameter and the connecting rod diameter of crankshaft.A good working condition of the sliding bearing can reduce the sliding friction and wear,make engine work smoothly and efficiently,and increase the service life of the engine crankshaft and connecting rod.Abnormal wear of engine connecting rod bearing is a common failure mode of connecting rod bearing.When the engine connecting rod bearings and related parts in the assembly,the existence of a bad size,assembly process control and lubrication system function failure,can cause abnormal working condition of connecting rod bearing.At the early stage of the bearings running under the abnormal condition can cause abnormal sound bad,especially in the cold car start early abnormal sound obvious,with the engine speed increased abnormal sound of continuous issued.When the bad continues to deteriorate,will eventually lead to the bearing of serious abnormal wear,and even happen to hold the shaft,so that the engine can not run and rejected,seriously affecting the quality of the vehicle and the driver's feelings.In this paper,a case study of the abnormal wear of the connecting rod bearing of a certain type of gasoline engine is carried out.Through the investigation and analysis of the practical problems,the paper analyzes the causes of the bad problems by using the method of the fault simulation and reappearance?The main research contents are as follows:firstly,from the theoretical knowledge of engine sliding bearing,combined with the actual production of the engine,the common failure mode of engine sliding bearing is analyzed,such as fatigue failure,wear and scratch,bite and corrosion.The main reasons for the failure of the engine parts,such as the size of the engine parts,the poor quality of the material,the bad cleanliness,the improper assembly clearance and the poor lubrication,are analyzed.Secondly,the specific engine connecting rod bearing abnormal wear problems,the use of causal diagram method,the actual production may cause abnormal wear of connecting rod bearings,machine,material,method and other factors of the investigation and analysis,the general factors to identify the main factors.Material composition and microhardness of detection of bearing fault analysis of connecting rod bearing semicircular perimeter higher degree,the fitting degree of the key dimensions of project performance testing.Through the engine bench test,the simulation of the failure of the foreign body,the bad parts,and the failure of the assembly process are carried out.In the end,the analysis of the defects of the inner chamber dimension,the bad bearing layer of the bearing and the material selection of bearing material,the cause of abnormal wear of the connecting rod bearing is improved.The performance parameters and the endurance test of the engine are carried out to test the performance of the engine with the improved rear connecting rod bearing.The whole process of the analysis is supposed to provide useful guidance and help for the engine connecting rod bearing production and the assembly of the engine.