US Patent 7517152 Squeeze film damper with variable support stiffness

A squeeze film damper assembly having a variable stiffness and damping control. The squeeze film damper includes a damper chamber formed by two flexible bellows chambers of the sides. A first pressure source is applied to the damper chamber to regulate the damping. A second pressure source is applied to the flexible bellows chambers to vary the stiffness of the damper. The flexible bellows chambers are secured between an outer member and an inner member of the damper assembly and form the sealed damper chamber. A pressure ratio between the bellows chambers and the damper chamber can vary to control the stiffness of the squeeze film damper.