The knocking dynamics of the vehicle transmission includes two aspects: one is the knocking in neutral, i.e. the knocking produced by the vehicle in neutral, when the vehicle is not driving but the engine is still working; the other is the driving knocking, i.e. the knocking generated during the driving process of the vehicle, at which time some idle gear pairs in the transmission system do not transmit load and are in a state of no load or light load, so thatCauses a slap between the teeth.A typical five-gear mechanical transmission is shown.
Flapping of the gear is usually occurring under light load, where the strength of the gear is secondary.Therefore, in the study of slapping dynamics of vehicle transmission system, the mechanism of slapping and the noise caused by slapping are mainly discussed.
Generally speaking, the main cause of gear flapping in the automobile transmission system is the change of rotation angular speed of the automobile engine. Because of the pressure of combustion gas in the engine and the periodic inertia force of reciprocating piston movement, the torque changes in a pulsating period, which causes gear flapping.On the other hand, the rattling vibration between the teeth is transmitted to the gear box through the gear body, drive shaft and bearing, which causes the vibration of the thin wall of the gear box, thus generating the rattling noise.