As the most commonly used motor centralized drive transmission system of electric vehicles, the motor is directly connected with the reducer, and the speed can be adjusted only by the wide speed range of the motor. Because the input speed of electric vehicle reducer is over 10000 rpm, the reducer at high speed faces the following problems
(1) The high speed of electric vehicle drive motor and high input speed is a great test for the gear transmission system of electric vehicle reducer; meanwhile, higher requirements are put forward for the strength and service life of the reducer;
(2) Because the noise of motor is much lower than that of fuel engine, and the current technology of permanent magnet synchronous motor and AC asynchronous motor is relatively mature, the noise control is very strict. Therefore, the vibration noise of reducer gear transmission is more prominent in electric vehicle;
(3) The high speed input of electric vehicle reducer makes the vibration and noise of gear transmission system increase significantly;
(4) The high speed input of electric vehicle reducer increases the tooth frequency of gear transmission system, and its vibration response frequency is higher than that of traditional fuel vehicle. At this time, the high frequency noise will make the passengers feel uncomfortable. Therefore, the vibration and noise of electric vehicle reducer has a great impact on the overall comfort of the vehicle.
Due to the above reasons, the vibration and noise of gear transmission system under high speed of electric vehicle reducer has become an important problem affecting the vehicle performance. If the design of high-speed gear reducer is unreasonable, it will have a negative impact on the stability, comfort and safety of electric vehicles. Therefore, it is of great theoretical and practical significance for the design and analysis of the reducer and other high-speed gear transmission systems to systematically study the vibration characteristics of helical gear transmission under high-speed conditions, and to obtain a complete set of analysis methods and vibration and noise reduction measures for high-speed gear transmission system.