Patent ID: 6871857

Claim:
A mechanical sealing device for preventing fluid leakage, comprising: a support plate ( 1 - 2 ) mounted at a position around a hole ( 1 - 1 ) formed through a sidewall of a fluid tank ( 1 ) for receiving a first shaft ( 2 ) in the hole ( 1 - 1 ), with a plurality of bolt rods ( 1 - 3 ) arranged on said support plate ( 1 - 2 ) at regular intervals; the first shaft ( 2 ) inserted into the hole ( 1 - 1 ), with a power drive unit ( 30 ) being mounted to the first shaft; a second shaft ( 2 - 1 ) having a pipe shape and coupled to the first shaft ( 2 ) exposed to the outside of the power drive unit ( 30 ); an interior sealing unit ( 31 ) installed on the first shaft ( 2 ) and an exterior sealing unit ( 32 ) installed on the second shaft ( 2 - 1 ), with two sleeves ( 3 ) fitted over the first and second shafts ( 2 , 2 - 1 ) provided on both sides of the power drive unit ( 30 ); first and second stuffing boxes ( 6 ) mounted to outer surfaces of the two sleeves ( 3 ) in such a way as to be opposite to each other, with a plurality of gland packings ( 5 ) being provided in each of the stuffing boxes ( 6 ); a flange ( 6 - 1 ) mounted to the first stuffing box ( 6 ) of the interior sealing unit ( 31 ), said flange ( 6 - 1 ) being fitted over the bolt rods ( 1 - 3 ) of the support plate ( 1 - 2 ) mounted to the fluid tank ( 1 ), and fixed by nuts ( 1 - 4 ) tightened to the bolt rods ( 1 - 3 ); and a support frame ( 35 ) mounted to the second stuffing box ( 6 ) of the exterior sealing unit ( 32 ) with a bearing ( 36 ) interposed between the frame and the second stuffing box, further comprising: a sealing chamber ( 14 ) formed by a flange ( 11 ), a seal casing ( 13 ) and a seal cover ( 12 ) at a position outside a gland ring ( 7 ) used for holding the gland packings ( 5 ) installed in the stuffing box ( 6 ) of each of the two sealing units ( 31 , 32 ); rotary and stationary sealing rings ( 17 , 16 ) provided in said sealing chamber ( 14 ), said rotary sealing ring ( 17 ) being fixed to the sleeve ( 3 ), said stationary sealing ring ( 16 ) coming into contact with both the sleeve ( 3 ) and the rotary sealing ring ( 17 ) and held by a slip ring ( 15 ) biased by a spring ( 18 ), with the spring ( 18 ) provided between the stationary sealing ring ( 16 ) and the flange ( 11 ); and additional sealing rings provided on inner surfaces of the gland ring ( 7 ) and the seal cover ( 12 ), and coming into contact with the sleeve ( 3 ).