Relation between Rotational Speed of Floating Bush Bearings and Rotor Vibration of a Turbocharger with Floating Bush Bearings

In response to the requirement for higher output of diesel engines in the recent years, IHI (Ishikawajima-Harima Industries Co., Ltd.) has recognized that a turbocharger with higher pressure-ratio and volume-flow rate will be required, and has commenced the development of such a turbocharger. One of the important technologies to develop the turbocharger with floating bush bearings is the evaluation of design parameters such as bearing peripheral temperatures and rotational speed of floating bush bearings. The present paper describes some measurements in a small size marine turbocharger to evaluate peripheral temperatures of the bearing, rotor vibration and rotational speed of 3-arc geometry floating bush bearings by using a slip ring system. Then for the rotational speed of floating bush bearings we have compared the prediction by a infinite length theory with measurements. The acquired results will be applied for designing of floating bush bearings.