Locating defects of a gear system by the technique of wavelet transform

This paper employs wavelet transform to detect the location of tooth defects in a gear system with high accuracy. Beginning with the review of relevant studies of gear failures, gear dynamics, and the theoretical background of the wavelet transform, a gear failure test rig is designed and constructed for implementing the technique of wavelet transform. The vibration signal measured from this rig in which the gears are worn naturally is used to verify the results from wavelet analysis for locating gear defects. To further demonstrate the advantage of multiresolution property of wavelet transform, a simulated system is employed for detecting the possible location of the defects in a gearbox. Results show that utilizing this approach may improve the ability for fault detection of a gear transmission system, especially when the faulty gear rotates in an angular speed close to those of other gears.