Patent ID: 7322570
Filing Date: 2008-01-29
Classification: F16F

Abstract:
1. A fluid-filled vibration damping device comprising: a first mounting member; a second mounting member disposed spaced away from the first mounting member; a rubber elastic body elastically connecting the first and second mounting members together; a pressure receiving chamber partially defined by the rubber elastic body and filled with a non-compressible fluid, the pressure receiving chamber undergoing fluid pressure fluctuation during input of vibration to the device; an equilibrium chamber partially defined by a flexible layer for permitting a volume change thereof and filled with the non-compressible fluid; an orifice passage permitting a fluid communication between the pressure receiving chamber and the equilibrium chamber; a movable member disposed so as to partition the pressure receiving chamber and the equilibrium chamber from each other, and being elastically displaceable or deformable due to pressure difference between the pressure receiving chamber and the equilibrium chamber exerted on opposite faces thereof so that pressure fluctuation induced in the pressure receiving chamber in a frequency band higher than a tuning frequency of the orifice passage is absorbed to avoid a high dynamic spring constant of the mount; at least one short passage connecting between the pressure receiving chamber and the equilibrium chamber with a passage length smaller than that of the orifice passage, wherein an equilibrium-chamber-side opening of the short passage is open to a region where the movable member is displaced or deformed, and when pressure in the pressure-receiving chamber increases, the movable member is displaced or deformed toward the equilibrium chamber to thereby close the equilibrium-chamber-side opening of the short passage to have the short passage substantially closed, while when pressure in the pressure-receiving chamber decreases, the movable member is displaced or deformed toward the pressure-receiving chamber to have the short passage operative.