Study On The Application Of Vibration Velocity Method In The On-line Noise Measurement Of Automobile Gearbox

Gearbox is one of the important parts of automobile, whose working noise is not only the important resource of total noise of automobile but also an important mark of its quality. Many gearbox manufacture factories wish to measure gearbox noise one by one in the manufacture locale, but traditional noise measurement methods with sound pressure level meter and sound intensity method can't meet their need. A new noise measuring method is needed to be developed anxiously, which can measure the gearbox noise easily, fast and accurately. Based on the detailed analysis of the automobile gearbox and its generation mechanism of noise and the coupling theory of shell structure surface vibration and its radiated noise, this paper introduces a simple, high efficient method which has been proved to be adaptable for the on-line noise measurement of the automobile gearbox. This method allows one to estimate the total sound pressure level of the noise radiated by the automobile gearbox from the sound pressure level of the noise radiated by its each main noise-radiating surface. And the noise radiated by each main noise-radiating surface can be estimated from the vibration velocity of the representative vibration measurement point on the corresponding noise-radiating surface.