Bidirectional hydrodynamic rotary seal

A hydrodynamic rotary seal (100) for bi-directional rotation and pressure, the rotary seal being generally ring-shaped and comprising:

• a seal first end (120f) and a seal second end (120s) facing in generally opposite directions;
• a dynamic lip (24) projecting radially inward and having a first side (24f) and a second side (24s), the dynamic lip defining a plurality of hydrodynamic waves (26) on the first side and a plurality of hydrodynamic waves (26) on the second side, the dynamic lip defining a dynamic sealing surface (25) of annular form facing in a radially inward direction and located in intermediate relation to the seal first end and the seal second end, the dynamic sealing surface being the most radially inward surface of the dynamic lip;
• each of the plurality of hydrodynamic waves on the first side of the dynamic lip having a wave geometry between a wave first end and a wave second end, the wave geometry comprising a mouth (31) at the wave first end at the seal first end, the mouth having a portion recessed relative to the dynamic sealing surface and having a portion blending into the dynamic sealing surface, the wave geometry further comprising a multi-function edge (28) extending in a generally circumferential direction and located in intermediate relation to the dynamic sealing surface and the seal first end, the multi-function edge being skewed relative to the seal first end and being farthest from the seal first end at the wave second end and defining a trailing edge low point (36);
• and
• each of the plurality of hydrodynamic waves on the second side of the dynamic lip having a wave geometry between a wave first end and a wave second end, the wave geometry comprising a mouth (31) at the wave first end at the seal second end, the mouth having a portion recessed relative to the dynamic sealing surface and having a portion blending into the dynamic sealing surface, the wave geometry further comprising a multi-function edge (28) extending in a generally circumferential direction and located in intermediate relation to the dynamic sealing surface and the seal second end, the multi-function edge being skewed relative to the seal second end and being farthest from the seal second end at the wave second end and defining a trailing edge low point (36);
• wherein the trailing edge low point on the first side of the dynamic lip is circumferentially spaced from the trailing edge low point on the second side of the dynamic lip.