US Patent 7419144 Fluid filled vibration damping device

A fluid filled vibration damping device wherein a first and second mounting member are connected by a main rubber elastic body, a pressure receiving chamber partially formed by the rubber elastic body and an equilibrium chamber partially formed by a flexible film are formed on either side of a partition member supported by the second mounting member, an orifice passage is formed for permitting a fluid communication between the pressure receiving chamber and equilibrium chamber communicate both having a non-compressible fluid; and a movable rubber plate is housed in a housing space so that minute pressure fluctuations in the pressure receiving chamber can be absorbed by the equilibrium chamber by means of the movable rubber plate. The movable rubber plate includes at least partially a corrugated part expanding generally a form of a corrugated panel by means of continuous depressions and protrusions.