Bidirectional seal with elliptical sealing barriers

摘要

A bidirectional shaft seal includes a plurality of concentric, radially-staggered contact surfaces arranged so as to engage a shaft along elliptical contact bands. Each contact band forms a static and dynamic barrier to prevent leakage under clockwise and couterclockwise shaft rotation. The elliptical contact may be achieved by offsetting the center of the seal lip from the axis of the shaft or by eccentrically clamping or bonding the seal lip within a seal case and mounting the seal lip concentrically with the shaft.