Optimal Design Of Powertrain Mounting System In The Engine Test Bench

Engine vibration is a critical factor of travelling comfort and NVH performance. And this is mainly caused by two reasons. One is inspired by the road surface. The other is caused by the engine itself. With the improvement of the road surface and the engine mounting system, the road surface excitation will get smaller and smaller. So to reduce and isolate engine vibration effectively is becoming important research topics in the car design.This paper is research on a engine test bench equipped with a VM engine. The study objective is to reduce the vibration of its engine powertrain. Optimizing the powertrain mounting system to reduce the vibration and noise of the engine test bench. So improve the test environment of the engine test bench. The research is mainly carried out on the following aspects.First of all, it completed the preliminary design of mounting system according to the design principles of the mounting system and the actual situation of the test bench. It built a three-dimensional rigid structure model of the engine powertrain using the modeling software SolidWorks. Then imported into the mechanical system dynamics analysis software ADAMS and built its vibration model based on the theory of mechanical system dynamics. And then established its mathematical model by using mathematical method.Secondly, it calculated the excitation of the VM engine according to the gas combustion and the inertia imbalance factors. And detected the stiffness and damping coefficients of the rubber mount in relevant frequency by experimental method. Then simulated and analyzed its forced vibration at idle work in ADAMS. At the same time tested the actual vibration of the engine test bench by acceleration sensors arranged in the bench. Then compared with the dynamics simulation results and verify that the physical and mathematical model building is reasonable.Finally, keep the excitation and constraints, changes some parameters such as the number of mount point, coordinates of the location, stiffness and damping in the ADAMS model. The goal is to reduce the vibration in engine power mount system. Then did the objective optimization in ADAMS. Calculated out the optimal mount system layout program itself. And then simulated the program in ADAMS. Evaluate the optimization program by comparing with its vibration before optimization.