초록 ▼

A mechanical face seal includes a pair of relatively rotatable seal rings having opposing seal faces which define a sealing region therebetween. The sealing region extends radially between the inside and outside diameters of the seal rings to seal a fluid in a sealing chamber near one diameter there

A mechanical face seal includes a pair of relatively rotatable seal rings having opposing seal faces which define a sealing region therebetween. The sealing region extends radially between the inside and outside diameters of the seal rings to seal a fluid in a sealing chamber near one diameter thereof. The seal faces are provided with hydrodynamic lift features near the sealing chamber to provide a lift load that permits a liquid between the seal faces to form a fluid film therebetween. The hydrodynamic lift features primarily function to hydrodynamically generate a hydrodynamic lift load while a plurality of concentric grooves are also provided on the seal face to serve as a leakage barrier during shaft rotation of the that prevents the liquid film from leaking across the seal faces.

대표청구항 ▼

1. In a mechanical seal for sealing an annular sealing space between a housing and an axially-elongate rotatable shaft, said mechanical seal including a first seal ring mounted non-rotatably to said housing and a second seal ring rotatably connected to said shaft so as to rotate therewith, at least

1. In a mechanical seal for sealing an annular sealing space between a housing and an axially-elongate rotatable shaft, said mechanical seal including a first seal ring mounted non-rotatably to said housing and a second seal ring rotatably connected to said shaft so as to rotate therewith, at least one of said first and second seal rings being axially movable relative to the other of said first and second seal rings and having a biasing arrangement which biases said one seal ring axially toward the other, said first and second seal rings having opposing seal faces disposed in sealing relation with each other to define a sealing region extending radially along said seal faces, said seal faces being relatively rotatable and axially separable during shaft rotation, comprising the improvement wherein one of said seal faces includes hydrodynamic lift features in a seal face region near a first circumferential boundary of said sealing region, said hydrodynamic lift features generating a hydrodynamic load lift within said sealing region during shaft rotation which hydrodynamically counteracts said biasing member to separate said seal faces and hydrodynamically generate a liquid film therebetween within said sealing region, one of said seal faces further including a plurality of annular grooves which are disposed near a second boundary of said sealing region opposite said first boundary, said grooves having a shallow depth and being separated radially one from the other by a plurality of annular lands extending radially therebetween such that gas in said liquid film collects in said grooves while liquid is retained along said lands by surface tension, said grooves and said lands defining alternating rings of said gas and said film liquid to define a leakage barrier during shaft rotation which prevents radial flow of said film liquid from said hydrodynamic lift features across said grooves and out of said sealing region.