Experimental Investigation on the Effect of Housing Profile and Its Relative Position on the Performance of Semi-Active Journal Bearing

Demand for higher speeds, reduced noise and improved reliability along with other safety requirements necessitates an effectively controlled rotor dynamics system. The desired requirements are often not met by using conventional bearings which are passive in nature. Additional improvements can be achieved only with the aid of active or semi-active controls. A new concept adopted here is to conceptualize a semi-active journal bearing to simulate a multi-lobed journal bearing. This research work attempts to develop a semi-active journal bearing by modifying the profile of the bearing and position of the bearing with respect to the shaft. The performance is here defined in terms of attenuation of the vibration amplitude in the bearing plane. For different bearing profiles and various bearing positions, rotor responses are acquired experimentally and FE method is used to obtain extent of simulation with the experimental results. The study is predominantly experimental in nature, and a simple versatile instrumented test rig is designed and fabricated for the purpose. The results indicate a high potential toward practically realizing a semi-active control on journal bearing profile, resulting in quantitative reduction of vibration amplitudes and also benefits derived from optimally positioning the bearing.