Seal Assembly with Protective Filter

Abstract

A fluid seal assembly including a specialized protective filter unit which is adapted for use with a fluid seal, as well as to the combination of a protective filter unit with an associated seal unit to form a complete seal assembly. The seal provides increased reliability, particularly in those specialized seals wherein high internal pressure and the possibility of particulate contaminants are present.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical sectional view of a portion of the composite oil seal of the invention, showing one part of the filter and excluder portion locked in place within an associated high pressure seal and showing the counterbore and the shaft in phantom lines;

FIG. 2 is an end elevational view of the seal assembly of FIG. 1;

FIG. 3 is a fragmentary sectional view showing another form of filter and filter retainer and the excluder lip on the inside diameter of the filter unit;

FIG. 4 is a rear elevational view of the filter lip of FIG. 3;

FIG. 5 is a vertical sectional view of another form of seal assembly, showing a still further form of filter and excluder element of the invention;

FIG. 6. is a fragmentary vertical sectional view of a portion of the filter and excluder lip of another form of seal;

FIG. 7 is a vertical sectional view of a position of another form of seal and showing a filter element and an O-ring excluder element; and

FIG. 8 is a perspective view of the filter and excluder element of FIG. 7.

Claims

1. A fluid seal assembly including a fluid seal unit having an elastomeric seal body and a seal band defined by the meeting of air and oil side surfaces, said fluid seal being adapted to seal a reciprocable member, and a protective filter unit for said fluid seal unit, said protective filter lying on the oil said of said fluid seal, said fluid seal unit also including a relatively rigid, axially extending casing unit having an elastomeric outside diameter surface adapted to be snugly received within a seal counterbore, and an inside diameter elastomeric surface, said protective filter unit having an axially extending portion, a radially extending portion including a fine mesh filter screen, and radially innermost means adapted to contact said reciprocable member in particulate excluding relation, said axially extending portion of said protective filter unit snugly engaging said inside diameter elastomeric surface lying on said axially extending inner portion of said casing unit.

2. A fluid seal assembly as defined in claim 1 wherein said means for snugly engaging said portion of said elastomer lying on said axially extending casing unit on said protective filter unit non-removably engages said portion of said elastomer on said casing unit.

3. A fluid seal assembly as defined in claim 1 wherein said axial portion of said protective filter unit comprises a metal portion having plural metal barbs extending radially outwardly from the remainder of said axial portion, said barbs engaging said elastomer on said radially inner surface of said casing unit.

4. A fluid seal assembly as defined in claim 1 wherein said axially extending portion of said protective filter unit includes a plastic portion, said plastic portion including at least one projection thereon for engaging a counterpart groove portion of said elastomer lying radially inside an axially extending portion of said casing unit.

5. A fluid seal assembly as defined in claim 1 wherein said radially innermost means adapted to contact said reciprocable member in particulate excluding relation comprises a groove in said radially innermost means having a quad ring disposed therein, said quad ring being made from a fine mesh filter medium.

6. A fluid seal assembly as defined in claim 1 wherein said radially innermost means adapted to contact said reciprocable member in particulate excluding relation comprises a sealing lip bonded to said radially innermost portion.

7. A fluid seal assembly as defined in claim 1 wherein said protective filter comprises a plastic unit with an axial flange having a snug fit with said inside diameter elastomeric surface and an inner diameter comprising a plurality of fingers, some of said fingers lying in a first plane and the other of said fingers lying in a second plane spaced from and parallel to said first plane, said fingers retaining a microporous scraper/filter.

8. A fluid seal assembly as defined in claim 7 wherein said fingers retain an O-ring made from a microporous material.

9. A fluid seal assembly as defined in claim 6 wherein said sealing lip is made from a thermoplastic elastomer.

10. A fluid seal assembly as defined in claim 6 wherein said sealing lip is made from a thermoplastic vulcanizate.

11. A fluid seal assembly including a fluid seal unit having an elastomeric seal body and a seal band defined by the meeting of air and oil side surfaces of said body, said fluid seal being adapted to seal a reciprocable member, and a protective filter unit for said fluid seal unit, said protective filter lying on the oil said of said fluid seal, said fluid seal unit also including a relatively rigid, axially extending casing unit having outside diameter surface adapted to be snugly received within a seal counterbore, and an inside diameter elastomeric surface for receiving a protective filter unit, said protective filter unit having an axially extending portion, a radially extending portion including a fine mesh filter screen, and radially innermost means adapted to contact said reciprocable member in particulate excluding relation, said axially extending portion of said protective filter unit snugly engaging said inside diameter elastomeric surface in oil tight relation.

12. A fluid seal assembly for sealing a reciprocable member said fluid seal including a rigid casing unit having radially and axially extending flanges, an elastomeric portion formed radially inside said axial flange, a seal body including a pocket in said body for receiving a back-up ring, and a sealing lip having a seal band where air and oil side frusto-conical surfaces meet, and a protective filter associated with said fluid seal, said protective filter lying on the oil side of said fluid seal, said protective filter including an axial flange portion of said protective filter non-removably received by said elastomeric portion, a radially extending portion having a fine mesh filter forming a part thereof and radially innermost means adapted to contact said reciprocable member in particulate excluding relation.

13. A fluid seal assembly as defined in claim 12 which further includes a back-up ring disposed in said pocket.

14. A fluid seal assembly as defined in claim 12 which further includes a back-up ring disposed in said pocket, wherein said axial flange portion of said protective filter includes a plural barbs extending into said elastromeric portion formed radially inside said axial flange of said fluid seal. 12.

15. A fluid seal assembly as defined in claim 12 wherein said protective filter includes a rigid axial portion having at least one projection thereon for engaging a counterpart groove in said elastromer on said seal axial flange.

16. A fluid seal assembly as defined in claim 12 wherein said radially innermost means include a groove in said radial portion, said groove having a quad ring therin made from a fine mesh filter medium.

17. A fluid seal assembly as defined in claim 12 wherein said radially innermost means adapted to contract said reciprocable member in particulate excluding relation comprises a sealing bonded to said radially inward means.

18. A fluid seal assembly as defined in claim 12 wherein said protective filter comprises a plastic unit with an axially flange having a slight taper for being pressed-fit into said axially flange of said seal unit. Said plastic unit having a plurality of fingers, some of said fingers lying in a first plane and the other of said fingers lying in a second plane spaced from and parallel to said first plane, said fingers retaining a microporous excluder in the form of a scraper/filter.

19. A fluid seal assembly as defined in claim 12 wherein said fingers retain an O-ring made from a microporous filter material.