Research On Damage Mechanism Of Hydraulic Cylinder Seal Ring And Motion Characteristics

Hydraulic cylinder as an important execution part of engineering machinery,has a great impact on the working performance of machine.Hydraulic cylinder often has malfunction due to poor working conditions,complex and variable load,shock vibration and other causes,and internal leakage is one of the typical common failure.Damaged seal ring is one of the main factors leading to leakage in the hydraulic cylinder.In this paper,the damage mechanism and motion characteristics of the hydraulic cylinder seal are studied deeply.The main research contents are as follows:(1)Research on damage-internal leakage mechanism of hydraulic cylinder seal ring.The research introduces the structure of the QY110 crane leg cylind er and expounds the structure,material and sealing principle of DAS com bined seal in detail.It analyzes the damage and internal leakage of the sea l ring by establishing seal damage model according to the common dama ge form of the seal and using the method of fluid solid coupling,in whic h Fluent module(Fluent)and the static structural analysis module(Stati c Structural)are combined,on the basic of the workbench simulation plat form.Besides,by the analysis of range and variance and a set of orthogon al experiments designed,the influence of the characteristic parameters o n the internal leakage and the proportion of the impact are figured out.(2)Analysis of motion characteristics of hydraulic cylinder luffing mechanism under internal leakage.The hydraulic cylinder of luffing mechanism of QY110 mobile crane is taken as the object of study.Firstly,from the perspective of electromechanical coupling,on the the platform of ADAMS and AMESimsoftware,the electro-hydraulic compound model of the luffing mechanism is established which includes the boom structure,the variable-length cylinder drive system and the boom pitch angle position control system;then on the basis of complex vector anslysis,the Kinematic model is made and the pitching motion is analyzed for the luffing mechanism.ADAMS and AMESim co-simulation is performed,the influence of hydraulic cylinder leakage on mechanism movement is focus studied.The results demonstrate that the coupling model of the luffing mechanism and the simulation analysis of the pitch kinematics conform to the actual situation and the theoretical analysis results,internal leakage failure has a great impact on the performance of hydraulic cylinder and the whole machine.(3)Experimental verificationThe damage of outrigger cylinder DAS combination seal is prefabricated artificially.The hydraulic cylinder leakage test is based on the existing working conditions simulation test bench.By contrasting the internal leakage test results,theoretical calculation results based on the formula of small hole flow and simulation results of fluid-solid coupling,The results show that theoretical calculation results are close to Fluidsolid coupling simulation results,there is a deviation between the experimental results and the simulation results,but the regular pattern that internal leakage increases with increasing pressure is consistent.Because the fluid solid coupling of super elastic rubber material is recognized difficult by the industry and the relevant reports are few,the method of this study is to supplement and enrich the existing research on the damage mechanism of rubber seal ring in hydraulic cylinder.