Detection of Rattle Sources in a Gearbox Using Correlation Technique

The focus of this paper is a method to detect gearwheel pairs in gearboxes responsible for rattle. The aim of this work is to find a method, which enables the main source of rattle in a gearbox to be detected. This is done by correlating pre-determined (e.g. measured) Impulse Response Functions with the gearbox casing vibration. The Impulse Response Function describes the response on the casing due to an impulse force on the gearwheels. These responses are assumed to be characteristic for all impact events at that gearwheel. By comparing the gearbox vibration at a point with characteristic functions for the possible rattle sources, the most likely source can be identified. The method does not give a unique solution but rather relies on a comparison between the correlation of the gearbox casing vibration and different impulse responses. A main advantage of this technique is that once the Impulse Response Functions have been determined the detection of multiple sources can be carried out on a single point at the gearbox casing. The technique is demonstrated and tested on a running gear box rig. The results show that the used technique supplies means to determine which gearwheel is the main source of rattle.