REVERSE LIP POSITIVE VENTING SEAL

摘要

A fluid seal for sealing a space between an internal machine surface and a shaft, having a rigid portion sealing received within said surface and a sealing lip body contacting the shaft, the sealing lip body being bonded to a part of the rigid portion. The lip body has a primary lip of reduced size, crosssection and flexibility which includes an "oil side" surface facing towards the sealed region, and an "air" side surface facing away from the sealed region, with these surfaces meeting along a primary seal band which is spaced just apart from the associated shaft and is positioned there by pumping elements which have shaft-engaging surfaces as well as "working" surfaces adapted to return leaking grease to the sealed region. The auxiliary lip is much larger than usual and is spaced axially apart from the primary lip, leaving an annular groove of generally V-shaped cross-section between the two lips.