关键词: 非线性系统, 轴承, 缺陷, 分岔, 混沌

Abstract: Governing differential equations of motion of a rolling element bearing with a localized defect on its outer ring are established with consideration of the sources of nonlinearity such as Hertzian elastic contact force and internal radial clearance, and they are solved by the Runge-Kutta-Felhberg algorithm. The nonlinear dynamic behavior of the bearing is analyzed by means of bifurcation diagrams, Poincaré maps, frequency spectrum diagrams as well as such time domain parameters as mean square value, crest factor， and kurtosis. Simulation results show that various kinds of periodic, quasiperiodic, and chaotic responses exist in the system. The main route to chaos is doubling bifurcation. The crest factor ratio can be used in the medium and low speed regions to detect a localized defect on the outer ring. The kurtosis ratio can be used for defect detection at relatively low rotation speeds, and the mean square value ratio can be used in a broad rotation speed range except for few speeds that depend on the bearing structure.

Key words: nonlinear systems, bearing, defects, bifurcation, chaos