Fluid-filled cylindrical elastic mount having three fluid chambers and

Abstract

A fluid-filled cylindrical elastic mount having an inner sleeve and an outer sleeve, and an elastic body interposed therebetween. The elastic mount also has a primary fluid chamber adapted to undergo pressure changes upon application of a vibrational load to the mount, and a first and a second auxiliary fluid chamber partially defined by a first and a second flexible diaphragm, respectively. The second flexible diaphragm has a greater stiffness than the first flexible diaphragm. A non-compressible fluid flows between the primary and first auxiliary fluid chambers, through a first orifice passage tuned to a first frequency range, and a second orifice passage tuned to a second frequency range that is higher than the first frequency range. The fluid also flows between the primary and second auxiliary fluid chambers, through a third orifice passage tuned to a third frequency range that is higher than the second frequency range. The elastic mount further includes a valve for selectively permitting or interrupting flow of the fluid through the second orifice passage between the primary fluid chamber and the first auxiliary fluid chamber.