Vibration Reducing Analysis And Optimization Of Powertrain Mounting System For Wheel Loader

With the development of technology, operation capability of construction machinery is not the only standard to judge mechanical equipment, the vibration and noise performance becoming the primary condition for sales in the market. Powertrain as the main vibration source of vehicle, assembled on the frame by rubber mounts, unbalanced inertial force and torque ripple transmit to the cab in the progress of operation and has a great influence on the vehicle NVH performance. Therefore, reasonable design of powertrain mounting system would decrease vibration transmission to the frame and cab. On the other hand, it could also avoid the premature failure of components aroused by intense vibration.This paper researches the intense vibration of wheel loader in the progress of operation. From the experiment, powertrain mounting system produces resonance under different rotating speed and vibration isolation characteristics of mounts performs poorly, So there’s a need to optimal design of powertrain mounting system. Through extensive reading literature, gets the design procedures of powertrain mounting system and vibration isolation theory, established six degrees of freedom model of powertrain mounting system by applying lagrange equation. Based on the dynamical model, modal characteristics, energy decoupling rate and dynamic responds of powertrain mounting system are established.Get the basic parameters of powertrain mounting system through experiments, including the location of powertrain center, rotational inertia, product of inertia, and install location, angle, rubber stiffness of mounts. On the basis of dynamical model of powertrain mounting system, compiles modal characteristic calculation procedure based on MATLAB software. Calculation results prove to be accurate and reliable compared with multi-body dynamics software ADAMS, and obtains the direction of optimized design of powertrain mounting system.Using the mount parameters as optimum variable, aiming to improve system decouple rate and decrease counterforce of each mount, establishes optimization model of powertrain mounting system. According to the optimization model, develops the optimal design software for powertrain mounting system based on MATLAB/GUI, adopted sequential quadratic programming and genetic algorithm as optimization algorithm, realizing the functions of modal calculation, optimal design, and dynamic response of mounting system.The paper carries out the optimization of powertrain mounting system using the optimal design software. Compared two kinds of optimization schemes, genetic algorithm as a global optimization algorithm, its optimization result is better than sequential quadratic programming, so adopts the result as final scheme designed by genetic algorithm. Comparing the before and after optimization experimental data, the vibration acceleration of frame and cab after optimization is lower than original type, and resonance of mounting system has been improved a lot. The test result shows that, vibration isolation of powertrain mounting system improved significantly, furthermore, the optimization software is valuable and creditable.