Patent ID: 6109617
Filing Date: 2000-08-29
Classification: F16J

Abstract:
A gas seal assembly for sealing an opening between a rotary shaft and an object through which the shaft extends, the seal assembly comprising:a) a first seal ring which defines a first sealing face,b) a second seal ring which defines a second sealing face opposite the first sealing face,c) biasing means for biasing the sealing faces together, andd) a seal housing which is sized to contain the seal rings and form an annular space which surrounds the seal rings,wherein the first and second seal rings are rotatable relative to one another, wherein the first sealing face defines a plurality of annularly spaced-apart geometric impressions which extend radially from a first intermediate diameter between the inner and outer diameters of each of the first and second sealing faces to a second intermediate diameter between the inner and outer diameters of each of the first and second sealing faces, and wherein the second seal ring further defines a plurality of annularly disposed fluid pathways which extend through the second seal ring thereby placing the annular space in fluid communication with an annular groove formed in the second sealing face, the annular groove having an outer annular groove diameter greater than the first intermediate diameter of the geometric impressions and an inner annular groove diameter which is greater than the inner diameter of the first sealing face, so that (i) the sealing faces are not in contact with one another when the rotary seal ring is sufficiently rotated, (ii) when the sealing faces are not in contact with one another, a gas may recirculate across the space between the sealing faces into the annular space and back through the fluid pathways to the annular groove, and (iii) when the sealing faces are in contact with one another, the flow of gas across the sealing faces is impeded.