Optimization for Powertrain Mounts of a Heavy-Duty Truck Based on the Mounts with Adjustable Stiffness

To improve the vibration isolation performance of the powertrain mounting systems (PMS) on heavy-duty trucks, firstly, the vibration isolation performance test and energy decoupling calculation of the PMS were carried out, and the cause of the problem was clarified. Then the front mounts stiffness was optimized and taking the optimized stiffness values as the goal, a novel rubber mount with adjustable stiffness was designed, and its stiffness adjustment characteristics, dynamic characteristics and vibration isolation performance were studied. Finally, to control the weight and cost, taking the stiffness values after adjustment as the goal, conventional front mounts were designed, and the reliability and durability, vibration isolation performance and dynamic characteristics were studied. The results show that the vibration isolation performance of the optimized mounting system is significantly better than that of original system. Under idle and rated speed conditions, the average vibration isolation rate of each mount is increased by 13% and 6.2%, respectively, and the average comprehensive vibration intensity of each key point on the cab is reduced by 30% and 37%, respectively. The mounts also have good reliability and durability. In different development stages, the combined application of mounts with adjustable and non-adjustable stiffness is beneficial to the improvement of development efficiency and quality and the control of cost, which has a certain guiding significance for the development of PMS.