Dynamic Response of Rigid Rotors Supported on Rolling Element Bearings With an Outer Raceway Defect

This paper is concerned with the nonlinear dynamical response of a rigid rotor supported on rolling element bearings with defects in the outer raceway. The rotor is modeled with five degrees of freedom, and the bearings are modeled with nonlinear forces arising from Hertzian contact stresses. Then we introduce a defect into the roller bearings with a controllable parameter, and analyze the effect of the growth of this defect on the dynamic response of the system using serveral signal processing tools such as spectrum, cepstrum and envelope methods. Numerical results are obtained for a screw compressor rotor. We examine these results with the idea a potential application towards the development of automated condition assessment tools for machinery diagnostics and prognostics. It appears from the results that no single tool is ideal, and that a combination of existing tools could possibly lead to a good strategy.