Sealing between a rotary and a stationary member

Claim 1

In combination, a stationary member having inner and outer walls and an opening therein, a rotatable member extending through said opening, a seal mounted on said rotatable member having a flexible, circumferentially extending lip engaging the inner wall portion surrounding the opening in said stationary member and defining a circumferential contact zone therebetween, the area between the outer surface of said lip and said inner wall of said stationary member defining an air chamber, the area on the opposite side of said lip defining a lubricant chamber, the highest level of lubricant in said lubricant chamber being not greater than a horizontal plane through the lowest extremity of the opening in said stationary member when the parts are at rest, collector means on said stationary member for collecting lubricant leaking past said contact zone and flowing therefrom along said wall in the direction of said opening out of contact with said lip, director means for directing the lubricant collected by said collector means into contact with said lip, means defining at least one aperture in said lip adjacent the outer terminal edge thereof extending between said air chamber and said lubricant chamber and disposed at an angle relative to the axis of rotation of said rotatable member, the centrifugal force upon rotation of said rotatable member acting on lubricant contacting said outer surface of said lip radially inwardly of said contact zone to evacuate said lubricant through said aperture back to said lubricant chamber, said aperture being of a size whereby the capillary force, adhesion and surface tension combined is less than the centrifugal force acting on lubricant flowing radially inwardly along said inner wall past said contact zone, said aperture of said rotational member being disposed in each cycle of rotation above the lubricant level in said lubricant chamber thereby preventing pressure buildup in said lubricant chamber.