Fluid-filled resilient bushing having damping means within fluid chambers

Claim 1

A fluid-filled resilient bushing, comprising: an inner sleeve; an outer sleeve disposed in radially outwardly spaced-apart relation with said inner sleeve, and having a plurality of apertures; a sealing sleeve fitted on an outer circumferential surface of said outer sleeve, so as to fluid-tightly close said plurality of apertures; a generally annular resilient member interposed between said inner and outer sleeves so as to connect the inner and outer sleeves, and having a pocket and an axial void which are located opposite to each other in a diametric direction of said inner sleeve parallel to a first direction in which the bushing receives a vibrational load, said pocket being aligned with one of said apertures in said outer sleeve, and said void being formed over an entire axial length of said resilient member; said sealing sleeve and said resilient member cooperating to define a fluid-tight pressure-receiving chamber such that said one of the plurality of apertures is fluid-tightly closed by said sealing sleeve, said pressure-receiving chamber being filled with an incompressible fluid; an elastically yieldable thin-walled partition member disposed in said axial void, so as to form at least one recess aligned with the rest of said plurality of apertures, respectively, said sealing sleeve and said resilient member cooperating to define at least one equilibrium chamber such that said rest of the apertures is fluid-tightly closed by said sealing sleeve, said at least one equilibrium chamber being filled with said incompressible fluid; means for defining at least one orifice which communicates with said pressure-receiving chamber and said at least one equilibrium chamber, and which permits flows of said incompressible fluid between said pressure-receiving chamber, and said at least one equilibrium chamber; a stopper block supported by said inner sleeve, and having a stopper portion which is disposed within said pressure-receiving chamber and which extends from a bottom of said pocket, substantially in said first direction, said stopper portion having a radial end face spaced apart from said outer sleeve by a predetermined radial distance in said first direction, said radial end face having a peripheral edge which is spaced apart from a periphery of said pressure-receiving chamber in a second direction perpendicular to said first direction, said peripheral edge of said radial end face and said periphery of said pressure-receiving chamber cooperating to define therebetween an annular spacing in a plane which is parallel to said second direction and an axial direction of said resilient member; damping means provided on said radial end face of said stopper portion of said stopper block, said damping means projecting from said peripheral edge of said radial end face substantially in said second direction, such that said damping means cooperates with said periphery of said pressure-receiving chamber, to define in said plane an annular gap which is smaller than said annular spacing.