Study On Lubrication Performance And Axial Trajectory Of Splash Lubrication Connecting Rod Bushing

The connecting rod bushing is the bearing part between the piston pin of diesel engine and the small head of connecting rod.Connecting rod bushing with small head of connecting rod,piston pin is used for interference fit and clearance.Due to high explosive pressure and inertial forces at work,the alternating load of the connecting rod is not parallel to the piston pin axis.In order to get closer to the reality,by studying the axial trajectory of the piston pin,the lubrication characteristics of the small head bearing of the connecting rod are analyzed with the splash lubrication.Therefore,it provides practical value guidance for the oil groove and oil hole in the inner surface of the connecting rod liner.In this paper,kinematics and dynamics analysis of crank-link mechanism of a certain type of engine are carried out.Get the load on the piston pin during the engine cycle.Based on the theory of finite element and nonlinear multibody dynamics,elastic hydrodynamic lubrication is used as the calculation method,and the multi-body dynamics model of small head bearings is established by using AVL EXCITE PU.The engine speed,bearing clearance,oil groove opening position as the influencing factors.Through the axis trajectory,the minimum oil film thickness,the lard membrane pressure,lube oil flow,outflow and the roughness of the friction power consumption is analyzed and compared on this little head bearing lubrication performance are studied.The specific conclusions are as follows.The lubrication of small head bearings at different speeds is different.The minimum oil film thickness at 1000 rpm and 4000 rpm is relatively small and easy to occur when poor oil lubrication leads to wear of bushing.The bearings are in good lubrication condition at2000 rpm and 3000 rpm.The influence analysis of the lubrication of the small head bearing of the connecting rod is analyzed by the four different radial radius clearance at the ratedworking condition of 3000 rpm.It is concluded that the minimum oil film thickness is the maximum when the radial radius clearance is 0.03 mm,and the maximum oil film pressure and roughness friction power consumption is moderate.On the basis of the above simulation conclusion combined with the rated conditions 3000 rpm axis path diagram of the first through the application of single factor experiment method to control the axial storage tank circumferential start-stop Angle and width of only two structural elements,On the opening position of the oil groove and oil hole simulation analysis,by comparing the connecting rod little head lubrication performance index is obtained within the liner circumferential surface of 75 °— 120 ° / 120 °— 285 ° and axial width is 25 mm when the best lubricating effect.