The Investigation of Mesh Stiffness and Vibration Response for Cracked Gearbox

Tooth crack is a general fault causing the operating failure of gearbox, for this account, the effect of crack on the meshing stiffness and vibration of gearbox are simulated in this paper to study and provide some theory basis for fault diagnosis. Firstly, the working process of cutting tooth is put in use to calculate the precise profile in theory of tooth, then the meshing stiffness is deduced under the new profile. Secondly, for the meshing stiffness, two methods calculating the effective tooth thickness under crack is introduced and compared in different crack depths. Afterwards, the vibration of gearbox is extracted by putting the meshing stiffness in a 6 degree of freedom dynamic model, and the effect of crack under two affecting lines on the gear dynamics is expressed by processing the residual signal using the fault detection indicators. This work aims at improving the dynamic simulation for gearbox, and it could be served as a reference for monitoring the great failure event in gearbox.