Patent ID: 6290235
Filing Date: 2001-09-18
Classification: F16J

Abstract:
A fluid sealing system for installation within an assembly including a stationary machine part having a generally annular surface which extends along a central longitudinal axis intermediate an upstream high and a downstream low fluid pressure side of the assembly, and a movable machine part having a generally cylindrical surface disposed in concentric opposition to the annular surface of the stationary machine part, the movable machine part being reciprocable along the central longitudinal axis intermediate the high and low fluid pressure sides of the assembly, and the annular surface of the stationary machine part having at least an upstream first gland and an axially spaced-apart, downstream second gland respectively defined therein intermediate the high and low fluid pressure sides of the assembly, the first and second gland each having axially spaced-apart upstream and downstream end walls and a peripheral wall extending therebetween radially circumferentially about the longitudinal axis, said system comprising:a generally annular secondary seal member configured to be received within the second gland coaxially intermediate the cylindrical surface of the movable machine part and the peripheral wall of the second gland;a generally annular primary seal member configured to be received within the first gland coaxially intermediate the cylindrical surface of the movable machine part and the peripheral wall of the first gland, said primary seal member having axially spaced-apart first upper and lower end faces disposable in confrontation with, respectively, the upstream and downstream end walls of the first gland, and radially spaced-apart first inner and outer diameter faces, said first inner diameter face being formed to contact the cylindrical surface of the movable machine part along at least one dynamic sealing surface, and the first outer diameter face being formed to contact the peripheral side wall of the first gland along at least one static sealing surface, said first upper end face having a first inner portion and an outwardly-directed first valving portion including a first outer surface which is normally biased within the first gland in abutting contact with the peripheral surface thereof to define the static sealing surface of said primary seal member, said first valving portion being actuable responsive to a first fluid pressure developed intermediate said primary and said secondary seal member to open a first fluid passageway between the first outer surface of said first valving portion and the peripheral wall of the first gland admitting said first fluid pressure to the upstream high pressure side of said assembly; andone or more first peripheral channels for providing fluid communication between said first fluid pressure developed intermediate said primary and said secondary seal member and said first fluid passageway, each of said first peripheral channels coupling said first fluid passageway in fluid communication with said first fluid pressure and including a first axial channel portion formed into the first outer diameter face of said primary seal member to extend intermediate the first lower end face thereof and the static sealing surface of said first valving portion.