Analyzing the Dynamic Characteristics of Angular Contact Ball Bearings Considering Three-Dimensional Localized Raceway Defects

Abstract

Current research on localized raceway defects of angular contact ball bearings (ACBB) mainly focuses on assuming that localized raceway defects are cube-shaped defects characterized using a half-sine displacement excitation function. However, the assumption of a cube-shaped defect cannot accurately reflect the morphological characteristics of a localized raceway defect, and the half-sine displacement excitation function cannot be used to accurately describe the relationship between the geometric positions of rolling element and raceway in the region of localized raceway defects. In this study, a comprehensive dynamic model of an ACBB considering a three-dimensional localized raceway defect is established based on the nonlinear Hertz contact theory in conjunction with the outer raceway control theory using the improved Newton–Raphson iteration method. Three localized raceway defect distribution types, namely symmetric, offset, and deflection distributions, are considered. The established model is verified by comparing the results of the proposed model with those of existing literature. The dynamic characteristics of the ACBB were analyzed by investigating the effects of the geometrical size and distribution types on the time-varying contact angles, contact forces, and diagonal stiffness of the ACBB. The investigation results show that the appearance of localized raceway defect leads to the time-varying curves of contact angles, contact forces and diagonal stiffness having Λ- and V-shaped mutations in some time intervals; The variation tendencies of the Λ- and V-shaped mutations are significant with the increase in defect radial depth H, defect axial width a and angular distance θ_b. The increase in defect eccentric distance L is beneficial to the rolling elements disengaging from the defect area and it can weaken the influence of localized raceway defect on the time-varying contact and stiffness characteristics of ACBB. The time-varying contact and stiffness characteristics appear to change significantly when the defect deflection angle α_β increase to α_γ. The results of this study provide a theoretical basis for the fault diagnosis of localized raceway defects in ACBB.