Identification of gear wear damage using topography analysis

Abstract

Gear failure modes and their underlying mechanisms are usually identified by visual inspection, which relies on the skills and experience of the human observer and hence is prone to subjectivity and bias. Therefore, it is essential to design and implement objective methods to improve the identification of gear failure modes. In the present study, the 3D topography of gear surfaces affected by different types of wear modes, i.e., micropitting, pitting, and scuffing, was measured by means of white light interferometry. The surfaces were evaluated in terms of height, spatial, and function roughness parameters, according to ISO 25178-2. Besides, a new roughness parameter, named surface motion orientation (Smo), was proposed. Three features were found relevant to identify the differences between the gear surfaces affected by different failure modes: the shape of asperities distribution, the severity of damage, and the surface texture orientation with respect to the motion direction. The combination of the roughness parameters selected to quantify each of these features (Ssk, Sq, Smo)resulted in an objective classification of the assessed gear failure modes.