Simulation Analysis of Knocking Noise of Two Speed Automatic Transmission in Electric Vehicle

Knock noise is a kind of transmission noise. It is very important to study the knocking noise of transmission because it has the characteristics of jumping noise level and wide frequency band， which is different from other noises. A two speed automatic mechanical transmission of a pure electric vehicle is taken as the research object， and the multi-body dynamics model of the transmission gear transmission system is established. The meshing force and angular acceleration of the transmission gear and the loose gear in the running process are analyzed. The gear with the largest knocking noise is theoretically calculated. Taking this as an example， combined with the simulation results of the bearing dynamic load， the accuracy of the gear dynamic model is indirectly verified by theoretical calculation of the vibration response of the transmission structure， and the influence of the retarding torque on the knocking noise is studied.