Resilient bushing structure filled with viscous fluid

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; a generally annular resilient member interposed between said inner and outer sleeves, so as to resiliently connect the inner and outer sleeves, said generally annular resilient member including an axially intermediate portion which has a generally annular recess open in an outer circumferential surface thereof, said outer sleeve fluid-tightly closing said annular recess, and thereby cooperating with said resilient member to define a generally annular fluid chamber filled with a viscous fluid; and gap-forming means for defining a pair of shearing gaps as two opposite portions of said annular fluid chamber which are opposite to each other diametrically of said inner sleeve, in a first diametric direction perpendicular to a second diametric direction (P) in which the bushing receives a vibrational load, said pair of shearing gaps extending substantially in said second diametric direction, each shearing gap defined by a first face and an opposite second face, and each shearing gap having a dimension as measured in said first diametric direction, which dimension is determined to be small enough to enable masses of said viscous fluid in said shearing gaps to provide a viscosity resistance upon application of shearing stresses to said masses due to said vibrational load received by the bushing, the first and second faces being moved relative to each other parallel to the second diametric direction upon application of a vibrational load to the bushing in the second diametric direction.