Study On The Way To Improve NVH Performance Of Auto Transmission

With the improvement of people's living standards,there is a new expectation for the comfort and quietness of using the car.As one of the core components of the vehicle,the Auto-Makers has also put forward strict requirements on NVH performance.And the gear whine noise is the most and important problems to be solved.Therefore,in this paper,the 2nd-shift-gear-whine noise of a transmission is to be studied for improvement methods,and to achieve a good level of performance.Firstly of all,working for testing and analysis noise data with the gear whine.To be acquiring and analyzing noise data under the condition of noise-near-ear and noise-vibration near transmission by using the LMS.Test Lab in vehicle,to identify the characteristic of frequency and order and speed range,as the main noise source of transmission;at the same time,acquisition the noise data on test bench to further confirm the noise characteristics of monomer transmission,to exclude the influence of vehicle;by using the contact spot test bench,gear contact analysis with a specific torque,analysis of whether there is a partial loaded state.Secondly,through professional software for modeling,virtual simulation analysis of transmission,analyses the Transmission Error,contact stress,contact area and the acceleration response at the transmission bearings position,namely gear whine simulation analysis;at the same time,the optimization design of the gear repair's parameters,then with validated the simulation again and test in real vehicle and bench and subjective eavaluation,the results show: the optimized method meet the objectives and requirements.Thirdly,according to the process,as the source-transfer path – response,put forward more solution approaches such as: transmission case optimization,sound insulation measures,gear grinding,to further improve the transmission NVH performance,so after these optimization,the result beyond the noise level of customer expectation.In this paper,with research for the improvement methods for the transmission gear whine,to achieve a significantly improved transmission NVH level,get a complete whine-noise solve steps and multiple ways to improve the performance of NVH.