Optimization of engine and transmission mounting system for a V6 front wheel drive vehicle

Abstract

Engine mounts helps to attach power train with the frame of the vehicle. The engine mounts help to keep the power- train in its position with the SUV chassis as vehicle experiences several torque loads and inertial loads. The mounting system helps in controlling the motion of the engine and transmission unit, preventing it from physical contact with other components of the vehicle system from sudden impact due to vibrations. The power train Mounting system helps in several ways to keep the engine and transmission unit firmly in its position during vehicle motion and helps in better drivability. Engine along with transmission unit con– tributes 25% of total weight of vehicle, it is important to isolate noise and vibration generated in the engine entering into the vehicle cabin, as power train is the source of vibration in the vehicle. So, it is important to study and investigate rigid body mode shapes for the engine and transmission unit for particular position of mounting unit and spring stiffness. This paper investigates the engine mounting system location and spring stiffness for a vertically mounted v8 engine. The engine and transmission unit mounted on vehicle chassis by elastomeric bushings. The bushing acts as spring mass damper system, helping in isolation of vibration and noise entering into cabin also prevents physical contact of engine with other critical vehicle components. Design of experiments approach is used to study effects of design variables. By varying mount location and stiffness rates the effects of these variable on the power train mounting system is studied and appropriate mounting location and stiffness rates is suggested to improve overall NVH performance of the power train.