(1) At present, there are many methods to calculate the meshing stiffness of gears. For spur gears, helical gears and other different types of gear pairs, the meshing stiffness calculation methods considering different tooth surface factors such as tooth surface modification and tooth root crack have been studied. However, due to the different calculation resources and actual factors, the accuracy of the calculation results is also different. How to get a more realistic time-varying meshing stiffness curve is still a problem facing researchers.
(2) At present, there is not much research on the influence of meshing impact on the dynamic characteristics of gear transmission system. The main reason is that there is no accurate calculation method for the impact force of external meshing at present. At present, the calculation of out of line meshing impact force is mainly calculated by theoretical model, and there are a few related cases about meshing impact force obtained by simulation.
(3) At present, the research on the vibration characteristics of helical gear transmission is mainly concentrated in the case of low and medium speed, and the vibration analysis of helical gear transmission system under high speed is rare. The conclusion obtained from the dynamic analysis of gear transmission under the condition of medium and low speed is not fully applicable to high-speed gear transmission system.
(4) At present, in the research of gear transmission dynamics, most of the literatures focus on the influence of various excitation factors on the dynamic characteristics of single-stage gear system, while the research on the dynamic characteristics of two-stage and multi-stage transmission gear systems is rare, and most of them ignore the interaction between multi-stage gear pairs.
Therefore, the analysis of vibration characteristics of helical gear transmission of high-speed electric vehicle reducer is of great significance to high-speed gear transmission and other high-speed gear transmission systems of electric vehicles.