Patent ID: 7694540

Claim:
A device for suppressing the whirling vibration of a rotating-shaft system that includes at least a rotating shaft and a rotating rotor supported by the rotating shaft, said device comprising: a first anti-rotating casing for surrounding said rotating shaft such that a radial direction of said casing is substantially orthogonal to said rotating shaft, wherein said first anti-rotating casing is arranged so that a whirling vibration of said rotating-shaft system can be transferred to said first anti-rotating casing, but wherein said first anti-rotating casing cannot rotate; a second anti-rotating casing laterally-placed apart from said first anti-rotating casing to create a clearance within a predetermined range between said first anti-rotating casing and said second anti-rotating casing; and suppressing means for suppressing the whirling vibration, said suppressing means including an elastic member having one end attached to a fixed position on an outside of said second anti-rotating casing, and having a free end, wherein said elastic member is compressed by applying a preload so as to suppress the whirling vibration of said rotating-shaft system from radiating outward thereof, and a stopper member that is located at a side of the free end of the elastic member for limiting an operating range of said elastic member.