Vibration analysis of fluid dynamic bearing spindles with rotating-shaft design

This paper is to present theoretical and experimental vibration analysis of fluid dynamic bearing (FDB) spindles with rotating-shaft design. In the theoretical analysis, a mathematical model is developed to predict half-speed whirls, rocking modes, frequency response functions, and shock responses. In the experimental studies, FDB spindles carrying multiple disks are tested at various spin speed. Frequency response functions (FRF) are obtained to verify the mathematical model. The theoretical results agree reasonably well with experimental results in both natural frequencies and resonance amplitudes.