Analysis And Optimization For Vibration Isolation Performance Of Hydraulic Excavator's Powertrain Mounting System

The controls of the powertrain vibration is the main content of the hydraulic excavator vibration controls, reasonable design of suspension system can effectively isolate the vibration of power assembly work, avoid excessive vibration and noise, improve the degree of comfort of the driver's control, to avoid the damage of the body joints early fatigue. Therefore, the analysis and optimization of the suspension system is the key measure to reduce the vibration and noise level of the excavator.In this paper, an ADAMS dynamics model and mathematical model are established for powertrain mounting system of a kind of domestic hydraulic excavators. Compared with the inherent characteristics of theoretical model and simulation model, simulation analysis in time and frequency domain based on model validation. The simulation results show that there is a serious coupling for powertrain mounting system, and the performance of vibration isolation is not satisfactory. And the steady state amplitude of the vertical support force is larger, optimization analysis must be conducted.Using the optimization software ISIGHT, an optimization model is constructed by taking the suspension stiffness parameters as design variables and considering energy decoupling as the objective function. Sensitivity analysis and optimization analysis are implemented with the constraints of rational allocation of natural frequency. At the same time, considering the limitations, energy decoupling method for decoupling rate and vibration transmission rate as the objective function, to carry out the deterministic optimization analysis, the optimized system coupling has been obviously improved, and the suspension vertical support force of the steady-state amplitude value is reduced greatly, the vibration transfer ratio of the system indicators have also been reduced.In order to obtain a more reliable result, considering the suspension element stiffness, installation location, installation angle and the system of inertia parameter uncertainty factors, six sigma quality design method is used for deterministic optimization scheme based on energy decoupling method for robustness analysis. Analysis results show that the deterministic optimization scheme under the interference of uncertain error to jump out of the constraints, can't meet the expected effect of optimization. Therefore, established a robust optimization model based on energy decoupling method, carried out the study of optimization. The performance of robust optimization is analyzed by six Sigma quality analysis method and Monte Carlo simulation method. It has shown that the energy decoupling of the robust optimization system is much better than that of deterministic optimization system. This robust optimization scheme is more suitable for practical engineering applications with its higher reliability.At the same time, in order to more fully analysis of the vibration isolation effect of suspension system, based on the six degree of freedom model, and created the frame of the flexible processing, established the vehicle the coupled model. To carry out the simulation analysis of suspension components within the working speed of vibration isolation transmissibility based on model validation. The results show that the suspension system in medium and high speed under the working speed meet the requirement of vibration isolation, but under the idle speed of vibration isolation transmissibility remains to be improved. Will different optimization of suspension stiffness in the vehicle model were analyzed, and the analysis results show that the optimized various suspension vertical vibration isolation transmissibility are in a reasonable scope, the system natural frequency constraint is more reasonable, and the system coupling degree is obviously improved. At the same time, the simulation analysis is created under the working conditions. And the results show that the performance of vibration isolation of the suspension system is improved after optimized. The established vehicle model has a certain reference value for the study of the vibration isolation of the suspension system.