抄録
Many rotors are supported by an oil film bearing which has high stiffness. Since the gap of an oil bearing is very small, we must suppress vibration as much as possible to prevent metal contact by well oil lubrication. Therefore the damping ratio is an important index to evaluate the rotor system stability. However it is difficult to identify the damping ratio under various operational conditions. In this paper, we introduce a new method using the modal open ioop transfer function. This method provides a more accurate Q-value by identifying the damping ratio considering only the selected mode to be measured. We evaluate experimentally the damping ratio of the oil film bearing with or without a dynamic damper. This development will be contributed to suppression of oil whip instability.
