An Experimental Study of the Stabilizing Effect of Floating-Bush Journal Bearings

While floating-bush bearings have been used in high-speed turbomachinery in recent years, there have been few investigations of the dynamic performances of such bearings. Experiments on the stability of a rotor with floating-bush journal bearings were carried out in this study. It was found that although the floating-bush would hardly rotate until the shaft speed reached the point where the oil-whirl occurred, the floating-bush stabilized the rotor system in a higher speed range. The stabilizing effect of the floating-bush bearing was conspicuous when the ratio between inner and outer clearance and the absolute clearance were large. It was also seen that the bush speed depended on its dimensions, particularly on the inner clearance and approached a nearly constant value as the shaft speed increased.