Patent ID: 7255335

Claim:
A fluid-filled active damping apparatus comprising: a first mounting member; a second mounting member; a rubber elastic body elastically connecting the first and second mounting members; a pressure receiving chamber filled with a non-compressible fluid, whose wall is partially defined by the rubber elastic body, and subjected to input of vibration; an oscillation plate defining an another portion of the wall of the pressure receiving chamber, and supported in a displaceable fashion; an electromagnetic actuator disposed on one side of the oscillation plate remote from the pressure receiving chamber, with an output member thereof connected to the oscillation plate, the oscillation plate being driven by means of current applied to the electromagnetic actuator to thereby control pressure in the pressure receiving chamber; a rigid annular guide member disposed about the oscillation plate with a slight gap interposed therebetween, such that the annular guide member is displaceable in an axial direction with respect to the oscillation plate; an elastic support member elastically interposed between and connected to the annular guide member and the second mounting member so that the annular guide member is elastically supported by and connected to the second mounting member via the elastic support member; an equilibrium chamber filled with the non-compressible fluid, whose wall is partially defined by a flexible diaphragm to readily permit change in volume; and an orifice passage for permitting a communication between the pressure receiving chamber and the equilibrium chamber, wherein the rigid annular guide member is disposed coaxially about the oscillation plate, and the slight gap between the annular guide member and the oscillation plate is made small enough to prevent flow of the fluid therethrough.