The solution method of the natural frequency of the system is introduced, and the natural frequency of the bevel gear transmission system of hybrid electric vehicle is solved by using the software simulationx. Through the Campbell diagram of the natural mode analysis corresponding to the system model and the unstable region under parameter excitation, it is obtained that resonance is inevitable in the working speed range. At the same time, the influence of several important parameters of bevel gear and bearing on the dynamic characteristics is analyzed. By changing the relevant parameters of bevel gear, the relevant natural frequency can effectively avoid the meshing frequency and improve the dynamic characteristics of bevel gear transmission system.
(1) Through the influence of time-varying meshing stiffness and meshing phase on the dynamic characteristics of the system, the influence of three different model parameters on parametric oscillation is analyzed, and the frequency is analyzed combined with the order analysis method which can effectively detect and show the resonance point. The study of these three cases shows that the relative phase of the meshing point of the bevel gear has a significant impact on the parametric excitation intensity, and the established model explains the causes of vibration (fault detection and diagnosis).
(2) The influence of backlash on the dynamic characteristics of bevel gear system is analyzed. This chapter analyzes the backlash in three cases. The research shows that the calculation of meshing vibration frequency of backlash coupling model can more accurately reflect the coupling vibration characteristics of bevel gear mechanism than that of uncoupled model, which is more in line with the actual requirements. With the increase of backlash, the overall amplitude increases. This shows that the larger the backlash, the greater the meshing impact of the bevel gear, which is in line with the actual situation. In addition, with the increase of backlash, the unstable region of bevel gear system becomes wider, and the bilateral impact range at resonance frequency becomes smaller. Through research and analysis, selecting the appropriate tooth side clearance in the parameter design of bevel gear can improve the dynamic characteristics of bevel gear system.
(3) Meshing damping also has a certain impact on the dynamic characteristics of bevel gear. From the analysis results, it can be concluded that the existence of meshing damping plays a positive role in vibration reduction. The larger the meshing damping is, the smaller the amplitude is, but the excessive meshing damping will increase the fuel consumption of the vehicle. Choosing the appropriate meshing damping plays a positive role in the study of the dynamic characteristics of bevel gear transmission system.
(4) By analyzing the influence of bearing stiffness on the dynamic characteristics of bevel gear transmission system, it can be obtained that the natural frequency of the system increases rapidly with the increase of bearing stiffness, but in some cases, the influence on the high-order natural frequency is almost minimal. In the bevel gear transmission system studied in this paper, within the range of ensuring the normal speed, select the large support stiffness of the central component, reduce the natural frequency, reduce the speed to be avoided, and improve the dynamic characteristics of the bevel gear transmission system.
(5) Through research and analysis, it is found that reducing the moment of inertia or increasing the stiffness parameters of the system in the bevel gear transmission system will improve the natural frequency of the system. Here, using the natural frequency and natural vibration mode analysis module of simulationx software, the moment of inertia with large sensitivity coefficient corresponding to the resonance frequency is obtained. By reducing the corresponding moment of inertia, the corresponding natural frequency can effectively avoid the meshing frequency band, It provides an effective method to improve the vibration mode structure. At the same time, the simulation results of the model verify that the modification of model parameters usually only leads to the improvement of one frequency range. Usually, the change of parameters may lead to the emergence of new resonance regions. Therefore, for the vibration system with multiple excitations, we should adjust and analyze the system in many aspects according to the actual situation, combined with economy and feasibility, and finally get a relatively stable system.
(6) The establishment of virtual prototype of bevel gear transmission system ensures that the virtual prototype model can realize three-dimensional animation according to the calculation results of the simulation process of nonlinear bevel gear transmission system. It provides an intuitive and reliable platform for studying the dynamic characteristics of bevel gear transmission system of hybrid electric vehicle.