The Mechanism Of Transmission Gear Whine And The Study For The Noise Decrease

When we drive car which using manual transmission accelerate or coast down，we’ll hear some whine noise in cab at special shift and special speed range. Especiallyat coast down condition，the cab is very quiet without engine noise，and the whinenoise is so harsh for driver.We using many channels for sound and vibration sensors to test for the MT，engine and cab. And then we use order noise analysis，through order noise track，wefind the specification of some special order noise is very consistent with oursubjective feeling for the whine noise. So we could confirm the source for the whinenoise is from the mesh gears. Then we using the sound data to do some coherenceanalysis, and we find the spread way of the whine noise.We using the gear mesh mark test in transmission at the test bench for the specialduty cycle. And we find some place to optimize for the gear mesh mark. Then weusing the Masta software to do some analysis for the gear mesh mark, we find thepractice result i consistent with the academic result.Through masta software using, we could set some guideline for guide ouranalysis, such as transfer error, contact stress, mesh mark. Then we could use masta to adjusthelix angle, pressure angle, crowning, tip relief and so on to find the right solution.Andthrough parts manufacture and vehicle test, we find the gear profile modificationhaving good effect to decrease gear whine.