Unitized grit seal with removable thrust bumper

A unitized, fluid retaining and grit exclusion seal assembly for heavy duty applications, said seal assembly comprising, in combination, an annular primary seal unit, an annular wear sleeve assembly having an annular wear sleeve casing, an excluder lip portion, and a removable thrust bumper element, said primary seal unit comprising a casing having a cylindrical mounting flange portion and a radially extending flange portion, an elastomeric primary seal body having one portion thereof bonded to a radially inner margin of said radially extending flange, said elastomeric seal body including air and oil side frustoconical surfaces meeting along a generally circular locus to form a primary seal band area of intended contact with a portion of said wear sleeve casing, said wear sleeve comprising a generally cylindrical, axially extending flange positionable in fluid tight relation with an associated rotary shaft to be sealed and a radial flange extending outwardly from the axially outer portion of said cylindrical flange, said excluder lip portion including a lip body bonded to an outer margin of said wear sleeve radial flange, said lip body also including surfaces defining an annular thrust bumper mounting groove, with the radially outwardly directed surface of said cylindrical flange engaging said seal band area on said seal lip body, said excluder lip portion having a lip end section engaged in end face seating contact with an outer end face of said primary seal casing radial flange, said thrust bumper element being made from a stiff but resilient high temperature resistant, lubricous plastic material and having a mounting land for complementary engagement with said mounting groove on said excluder lip body, said thrust bumper also having opposed tapered surfaces defining a contact area positioned opposite said end face of said primary seal radial flange.

A unitized, fluid retaining and grit exclusion seal assembly for heavy duty applications, said seal assembly comprising, in combination, an annular primary seal unit, an annular wear sleeve assembly having a wear sleeve casing, an excluder lip unit, and a removably mounted thrust bumper element, said primary seal unit comprising a casing having an axially extending mounting flange portion, and a first and second, axially offset, radially extending flanges an elastomeric primary seal body having one portion thereof bonded to a radially inner margin of said first radial casing flange, said primary seal body also including air and oil side frustoconical surfaces meeting along a generally circular locus to form a primary seal band area, and surfaces defining an annular mounting groove for said thrust bumper, said wear sleeve casing including a first, generally cylindrical flange positionable in fluid tight relation with an associated rotary shaft to be sealed, a first radial flange extending outwardly from the axially outer end of said first cylindrical flange, an inner end face on said first radial flange for engaging a portion of said thrust bumper, a second axial flange having a mounting surface for said excluder lip unit, and a second radial flange, with the radially outwardly directed surface of said first cylindrical flange being engaged in use by said seal band area on said primary seal body to create a fluid seal, with said excluder lip unit having a mounting body portion and a flexible lip portion, said mounting body portion being received over said mounting surface on said second axial flange on said wear sleeve, said flexible lip portion contacting a radially inwardly facing surface of said axially extending mounting flange of said primary seal casing, said thrust bumper element being made from a stiff but resilient high temperature resistant, lubricous plastic material, and including a thrust bumper body portion having opposed tapered surfaces meeting to define a narrow band of intended contact with an inner end face of said first radial flange of said wear sleeve casing, said thrust bumper further including a mounting land complementary to said mounting groove, with said thrust bumper being positioned relative to said inner end face so that in use, said narrow band is, at most, slightly spaced from said inner end face surface.