Patent ID: 7494130

Claim:
A bi-directional dynamic seal comprising: a lubricant side; a non-lubricant side; a sealing portion having an active surface communicating with said non-lubricant side and a leading seal edge at an end thereof, said leading seal edge facing said lubricant side, said leading seal edge defining an opening in which a shaft can be disposed, and said active surface operable to engage with and seal against a shaft disposed in said opening; and a plurality of pumping elements extending along said active surface and stopping short of said leading seal edge with a static dam therebetween, said pumping elements operable to capture lubricant that leaks past said leading seal edge and pump said captured lubricant toward said leading seal edge, past said static dam and back into said lubricant side due to relative rotation between said active surface and a shaft disposed in said opening regardless of a direction of said relative rotation, wherein said pumping elements are primary pumping elements each having two distal ends with termination points adjacent said static dam and an induction point at a location along said pumping elements most remote from said leading seal edge, and further comprising a plurality of secondary pumping elements extending along said active surface with said primary pumping elements disposed between said secondary pumping elements and said leading seal edge, said secondary pumping elements operable to capture lubricant that leaks past said primary pumping elements and direct said captured lubricant to said induction points of said primary pumping elements, and at least one of said secondary pumping elements intersects at least one of said primary pumping elements at an induction point.