Patent ID: 7044455
Filing Date: 2006-05-16
Classification: F16F

Abstract:
1. A fluid-filled vibration-damping device for connecting a power unit and a body of a vehicle in vibration damping fashion comprising: a first mounting member of shaft shape having a support shaft portion at one axial end portion thereof and a fixing portion at an other axial end portion thereof, said first mounting member being attached at the fixing portion to the power unit; a second mounting member having a cylindrical portion, said second mounting member being disposed relative to said first mounting member such that said first mounting member is located on a side of an opening portion of an axially upper end of said cylindrical portion of said second mounting member with an axial spacing therebetween and with said supporting shaft portion thereof axially inserted into said cylindrical portion of said second mounting member and said fixing portion thereof axially upwardly protruded from the one of axially opposite ends of said cylindrical portion, said second mounting member being attached to the body of the vehicle; an elastic body elastically connecting said support shaft portion of said first mounting member and said cylindrical portion of said second mounting member so that said opening portion of said one of axially opposite ends of said cylindrical portion of said second mounting member is fluid-tightly closed by said elastic body; a primary fluid chamber formed in said cylindrical portion of said second mounting member and located axially inwardly of said first mounting member, while being partially defined by said elastic body and filled with a non-compressible fluid; an auxiliary fluid chamber filled with said non-compressible fluid whose pressure varies relative to a pressure of said fluid filling said primary fluid chamber upon application of an axial vibrational load between said first mounting member and said second mounting member; a first orifice passage for fluid communication between said primary and auxiliary fluid chambers; a pair of working fluid chambers formed at respective circumferential portions of said elastic body that are opposed to each other in a diametric direction of said elastic body, so as to extend circumferentially with a circumferential length smaller than a half of a circumference of said elastic body, said pair of working fluid chambers being filled with said non-compressible fluid; and a second orifice passage for fluid communication between said pair of working fluid chambers, wherein each of said pair of working fluid chambers formed in said elastic body is partially defined by an axially outer elastic wall portion and an axially inner elastic wall portion having a spring constant in a radial direction perpendicular to said axial direction of said cylindrical portion of said second mounting member, which is larger than that of said axially outer wall portion in said radial direction, and wherein said axially outer elastic wall portion of each of said pair of working fluid chambers has elastic center line that extend radially outwardly while inclining to an axially upward direction so that said outer elastic wall portion extends substantially straightly in a diagonally upward direction from a radially inner portion thereof to a radially outer portion thereof, and an axially outer end face of the rubber elastic body extends substantially straightly in the diagonally upward direction from a radially inner portion thereof to an radially outer portion thereof, across an entire circumference of the rubber elastic body, in order to locate an elastic support center of the vibration damping device against an input vibrational load in a diametric direction in which the pair of working fluid chambers are opposed to each other on an axially lower end portion of the support shaft portion.