Fluid-filled elastic mount whose orifice passage has sufficiently large cross sectional area exhibits improved fluid-tightness

A fluid-filled elastic mount including (a) a first mounting member and a generally cylindrical second mounting member, which are spaced apart from each other in an axial direction of said second mounting member, (b) an elastic body elastically connecting said first and second mounting members so as to fluid-tightly close one of axially opposite open ends of said second mounting member, (c) a partition member made of metal and extending in a direction perpendicular to said axial direction, (d) a closure member made of metal and having a central through hole and a flexible diaphragm fluid-tightly closing said central through hole, said partition member and said closure member being superposed on each other and fixed at their peripheral portions to the other of axially opposite open ends of said second mounting member, by calking, so as to provide on one of opposite sides of said partition member a pressure receiving chamber which is partially defined by said elastic body and filled with a non-compressible fluid, and on the other of opposite sides of said partition member an equilibrium chamber which is partially defined by said flexible diaphragm and filled with the non-compressible fluid, and (e) an orifice passage for fluid communication between said pressure receiving chamber and said equilibrium chamber, said orifice passage being formed between said partition and closure members so as to extend in a circumferential direction of said partition and closure members, wherein an improvement comprises:

• said partition member including an axial protrusion formed at a radially intermediate portion thereof and having an outer circumferential surface extending in said circumferential direction thereof, and a cylindrical positioning shoulder located radially inwardly of said peripheral portion thereof,
• said closure member including an integrally formed cylindrical wall portion located radially inwardly of and protruding axially outwardly from said peripheral portion thereof, and an integrally formed annular plate portion extending radially inwardly from a protruding open end portion of said cylindrical wall portion,
• said partition and closure members being superposed on each other such that said cylindrical wall portion of said closure member is partially press-fitted onto an outer circumferential surface of said cylindrical positioning shoulder of said partition member so as to be positioned relative to said partition member in a diametric direction thereof, and that the annular plate portion of said closure member being superposed at an inner peripheral portion thereof on a protruding end face of said axial protrusion of said partition member to thereby provide an annular passage partially defined by and circumferential extending between said cylindrical wall portion of said closure member and said axial protrusion of said partition member which are opposed to each other in said diametric direction,
• said annular groove including a partition wall formed at a circumferential portion thereof, said partition wall protruding radially outwardly from the side of said partition member toward the side of said closure member such that said partition wall is elastically pressed against the side of said closure member to thereby fluid tightly intercept said annular passage in a circumferential direction thereof;
• and
• said annular passage being held in fluid communication with said pressure receiving chamber through a first communication hole formed on one of circumferentially opposite sides of said partition wall and with said equilibrium chamber through a second communication hole formed on the other side of said partition wall, to serve as said orifice passage.