Design Prediction of Stiffness for Bearing Support Structure Using Rubber Components

Abstract

Vibration characteristics of rotary machines depend on the critical speed map determined by the rotor structure, also the stiffness and damping characteristics of bearing and its surrounding structure supporting the rotor (bearing support structure). It is important to deal with and design the rotor-bearing system unitarily to obtain the desired vibration characteristics, however, there are numerous parameters of the system and this make its design comlicated. In this study, a simple design method was proposed to predict the stiffness of the bearing support structure using annular rubber components, and validation with experimental measurement of the vibration chracteristics was conducted. The measured vibration chracteristics of the rotor-bearing system accorded qualitatively with the one predicted by the proposed method, and critical speeds were well matched quantitatively after expanding the method with considering dynamic characteristics. We have considered the proposed method is simple and applicable to designs of rotor-bearing systems with bearing support structure using rubber components.