Vibration transmission control of a flexible shaft-bearing system using active/passive support

An active/passive support is proposed to suppress the transmission of vibration from a flexible shaft-bearing system to its foundation. The active/passive support consists of passive isolators and electromagnetic suspension, in which the former bears the static load while the latter provides suspension force for displacement adjustment and vibration suppression. The dynamic model of the shaft-bearing-foundation system is built on the Rayleigh-Ritz method. Based on this model, the adjustment of stiffness, the transmissibility of vibration, the vibration characteristics of the coupled system and the effectiveness of active control are analyzed. An adaptive control method with subband filtering and disturbance reconstruction is adopted and the performance is evaluated. The effectiveness of the active/passive support is also verified by experiment. Numerical and experimental results demonstrate that the transmission of vibration via the active/passive support can be greatly suppressed and the vibration of the foundation can be reduced almost to the same level.