Transmission & Gearbox NVH
By necessity, many automotive transmission, gearbox and transfer case assemblies are produced with significantly larger casing surfaces than, for example, an independently-suspended axle. The larger casing surfaces are more easily vibrated by gear mesh interaction forces, resulting in a higher proportion of radiated noise.
In general, this calls for an NVH measurement approach that takes account of casing vibration and hence radiated noise, so it is commonplace for systems to measure:
■ arrays (multiple channels) of microphones
and/or:
■ non-contacting laser vibrometers
■ spring-loaded vibration touch-probes
■ well-attached accelerometers (if test time permits)
Measuring Product Noise on the Factory Floor
If radiated noise is measured, it is important to ensure that the product noise can be measured over background noise. Noise "havens" are often employed to help obtain repeatable, and hence meaningful, measures of tonal noise, but measurement of gear-related tonal noise under such conditions comes with its challanges. ABD-experience & expertise is able to overcome these challenges, using well-proven techniques for measuring multiple channels (microphone arrays) and implementing appropriate subsequent processing.
.jpg){kind=spacer}
Transmissions & Transfer Cases