Abstract: Unitary radial lip seals are useful to provide permanent lubrication to rotary shaft and bearing assemblies. In addition, these seals also function as excluder seals to keep dirt, chemicals, and other contaminants from contacting the lubricated surfaces. However, previous radial lip seals have a tendency to wear or cut a groove into the associated rotary shaft, as the shaft is rotated during normal operation of the machine. The present disclosure describes a radial lip seal having a sleeve, a seal case, a faceplate and flexible member. This improved seal also has a second sleeve operably positioned between the shaft and the faceplate wiper ring that alleviates the tendency of the wiper ring to cut a groove into the shaft during normal operation of the machine.

Abstract: A unitary sleeve lip seal can be used to provide permanently lubricated sealed bearings in severe service conditions such as the track pins of track-driven vehicles and agricultural equipment. The seal has a labyrinthine exclusion path and multiple dust lips contacting the sleeve in addition to the main sealing lip. A garter spring encircling the main sealing lip may enable the seal to operate at moderately elevated pressures. The sleeve has a radial flange at the outermost end. Elastomeric lips extend between the sleeve flange and a faceplate that terminates the outside end of the seal housing. The seal is packed with water-resistant grease and can, when installed in association with grease-packed bearings can create a permanently lubricated bearing/shaft assembly that requires no re-greasing. Resilient coatings both protect the sleeve and case and also improve leak resistance, especially when the seal is retrofitted onto shafts that have been damaged.