Journal bearings, which are used in all kinds of rotating machinery, do not only support static loads, such as the weight of rotors and load caused by transmitted torque of reduction gears, but are, in addition almost the only machine element that is able to suppress various exciting forces acting on the rotating shaft. As rotating machines have become large and multi-staged, while compactness, high speed, and high output have also been realized in recent years, not only has the bearing load increased, but also the magnitude and variety of exciting forces. Therefore, the role and importance...