Based on the multi-body dynamics, statics and acoustics of the reduction box and gear system of the electric vehicle, the influence of gear parameters and gear modification technology on the vibration and noise characteristics and service life of the helical gear pair has been deeply studied through a large number of simulation and relevant tests, and a relatively systematic gear optimization and modification system has been established:
(1) Considering the actual working conditions of electric vehicles and the reduction of gear tooth strength due to gear tooth root modification, the tooth root modification and short modification are not considered during the modification. However, if the gear material strength and working conditions allow, these factors should be taken into account for in-depth study.
(2) The influence of the modification on the vibration and noise characteristics of the gear itself is reflected by the change of the radiated noise of the housing before and after the modification of the helical gear pair of an electric vehicle reducer. The follow-up research should try to directly model and simulate the gear system, so as to put aside other factors such as the housing, bearing, synchronizer, and further improve the accuracy of the simulation results.
(3) Due to the urgency of time, only a preliminary discussion has been made on the internal dynamic excitation of the gear, and the specific influence weight of each internal excitation (time-varying meshing force, time-varying meshing stiffness, transmission error) on its vibration and noise under different working conditions has not been obtained.
(4) The studied helical gear pair of an electric vehicle reducer is in the design and development stage. Whether it is the tool used for machining, high-precision machine tool, gear drawing, processing technology, etc., all need to be customized. The whole process generally takes several years. If conditions are available in the later stage, the gear should be manufactured according to the optimal modification plan, and then relevant test demonstration should be carried out.