Study On Dynamic Characteristic Analysis And Optimization Of A Marine Gearbox

As the support part of the whole gear box, the box bears various complex loads from transmission system, and it is often subjected to large interaction of bending, torsion and impact. To ensure its strength and stiffness to meet the use requirements, a bigger safety factor is usually chosen and the box's geometry size is increased. These measures will cause the weight increase, material waste and reduce the overall performance of the machine. Besides, based on the consideration of comfort, a higher requirement of vibration and noise on the box is also put forward. Traditional mechanical design method is difficult to adapt to the requirements of current industrial development. Therefore, using advanced structure optimization methods to research the gear box has important significance on improving performance of the gear box, reducing design and manufacturing costs and creating economic benefits.In this paper, taking a high-power marine gear box for study, a three-dimensional entity model and finite element model of the box are established and reasonable boundary conditions are applied,such as constraints and loads. On this basis, through the dynamic and static analysis, the model of natural frequency and vibration are gained, as well as the status of stress and strain of the box while it is working under forward and reverse conditions. The results show that the gear box has a large design margin of overall strength and stiffness, so it is necessary to further optimize its structure. Under the working condition, vibration and noise tests of the gearbox are made, and the result of finite element modal analysis is verified, as well as the causes of vibration and noise are analyzed. Topology optimization calculation and analysis of the box are made, considering the optimization results and specific structure of the box and the vibration and noise test and analysis, though comparison and argumentation, optimization method of the box is put forward. Under the same environment and boundary conditions, finite element analysis and calculation of the optimized model is made. The results indicate that a good weight loss effect is achieved on the basis of meeting the requirements of the box structural performance requirements.