Getrag Transmission Rattle Noise Prediction
System Modeling
Introduction
„Transmission Rattle“ is a noise phenomenon of vehicle transmissions and determines significantly the transmission quality with regards to the attribute NVH. It is initiated by the periodic torque fluctuation of combustion engines and occurs at the gears that are currently not in the power flow and can therefore move freely within their backlashes. The resulting impacts at the tooth contacts are transferred through the shafts and bearings to the transmission housing. The noise radiation at the outer housing surface can be perceived by the driver as unpleasant, broadband noise, and should be minimized.
For cost and timing reasons it is important to get predictions about the expected rattle quality in an early phase of the transmission development in order to make the right design decisions.
A calculation method to predict the rattle noise behavior of a transmission on a test rig will be described in this publication.