Seal assembly having a plastic annular sealing member with an integral sealing lip

Claim 2

In a seal assembly (10) positioned between first and second relatively movable members (14, 22) for sealing therebetween and cooperating therewith in defining a lubricant holding chamber (35), the seal assembly (10) including an annular sealing member (36) having an integral sealing lip (38) for retaining lubricant in the chamber (35) and for preventing the ingress of contaminants therein, and load means (42) borne by the first member (14) for urging the sealing lip (38) into sealing engagement with the second member (22), the improvement comprising: an annular polymeric plastic sealing member (36) having a dry coefficient of dynamic friction on lapped hardened steel in the range of approximately 0.05 to approximately 0.35 and a load/velocity relationship (PV) in the range of approximately 70.0 (2,000) to approximately 1576.0 (45,000).

Claim 3

The seal assembly (10) of claim 1 wherein the annular sealing member (36) is a material with a tensile strength in the range of approximately 27.580 MPa (4,000 psi) to approximately 206.850 MPa (30,000 psi).

Claim 4

The seal assembly (10) of claim 1 wherein the annular sealing member (36) has a hardness in the range of approximately 45 to approximately 95 on the Shore D scale.

Claim 5

The seal assembly (10) of claim 1 wherein the annular sealing member (36) has a tensile strength in the range of approximately 27.580 MPa (4,000 psi) to approximately 206.850 MPa (30,000 psi) and a hardness in the range of approximately 45 to approximately 95 on the Shore D scale.

Claim 6

The seal assembly (10) of claim 1 wherein the annular sealing member (36) comprises a thermoplastic resin containing approximately 18% polytetrafluoroethylene and approximately 2% silicone oil.

Claim 7

The seal assembly (10) of claim 5 wherein the thermoplastic resin is a polyamide polymer.

Claim 8

The seal assembly (10) of claim 6 wherein the polyamide polymer is hexamethyleneadipamide having repeating polymer chain units having the formula ##STR2##

Claim 9

The seal assembly (10) of claim 1 wherein the annular sealing member (36) comprises ultra-high molecular weight polyethylene having repeating polymer chain units having the formula --CH.sub.2 --CH.sub.2 ].sub.n.

Claim 10

A track joint (12) comprising: first and second pivotally connected overlapping links (14, 16) coaxially mounted along a pivot axis (18) to a concentrically disposed track pin (20) and associated cylindrical bushing (22) respectively, the bushing (22) having a radially extending, axially inwardly facing end face (34), a counterbore (26) disposed in the first link (14) and defined by a radially extending, axially outwardly facing end face (28) and a cylindrical surface (30); an annular spacer member (24) surrounding the pin (20) and extending between the end faces (28, 34) of the counterbore (26) and the bushing (22); and a seal assembly (10) disposed in the counterbore (26) for retaining lubricant in the track joint (12) and for preventing the ingress of contaminants therein, the seal assembly (10) including an annular polymeric plastic sealing member (36) having an integral sealing lip (38), load means (42) borne by the first link (14) for urging the sealing lip (38) into sealing engagement with the bushing end face (34), said sealing member (36) having a dry coefficient of dynamic friction on lapped hardened steel in the range of approximately 0.05 to approximately 0.35 and a load/velocity relationship (PV) in the range of approximately 70.0 (2,000) to approximately 1576.0 (45,000).

Claim 11

A track joint (12) comprising: first and second pivotally connected overlapping links (14, 16) coaxially mounted along a pivot axis (18) to a concentrically disposed track pin (20) and associated cylindrical bushing (22) respectively, the bushing (22) having a radially extending, axially inwardly facing end face (34), a counterbore (26) disposed in the first link (14) and defined by a radially extending, axially outwardly facing end face (28) and a cylindrical surface (30); an annular spacer member (24) surrounding the pin (20) and extending between the end faces (28, 34) of the counterbore (26) and the bushing (22); and a seal assembly (10) disposed in the counterbore (26) for retaining lubricant in the track joint (12) and for preventing the ingress of contaminants therein, the seal assembly (10) including an annular polymeric plastic sealing member (36) having an integral sealing lip (38), load means (42) borne by the first link (14) for urging the sealing lip (38) into sealing engagement with the bushing end face (34), said sealing member (36) having a dry coefficient of dynamic friction on lapped hardened steel in the range of approximately 0.05 to approximately 0.35 and a load/velocity relationship (PV) in the range of approximately 70.0 (2,000) to approximately 1576.0 (45,000).

Claim 12

The track joint (12) of claim 9 wherein the annular sealing member (36) is a material with a tensile strength in the range of approximately 27.580 MPa (4,000 psi) to approximately 206.850 MPa (30,000 psi).

Claim 13

The track joint (12) of claim 9 wherein the annular sealing member (36) has a hardness in the range of approximately 45 to approximately 95 on the Shore D scale.

Claim 14

The track joint (12) of claim 9 wherein the annular sealing member (36) has a tensile strength in the range of approximately 27.580 MPa (4,000 psi) to approximately 206.850 MPa (30,000 psi) and a hardness in the range of approximately 45 to approximately 95 on the Shore D scale.

Claim 15

The track joint (12) of claim 9 wherein the annular sealing member (36) comprises a thermoplastic resin containing approximately 18% polytetrafluoroethylene and approximately 2% silicone oil.

Claim 16

The track joint (12) of claim 13 wherein the thermoplastic resin is a polyamide polymer.

Claim 17

The track joint (12) of claim 14 wherein the polyamide polymer is hexamethyleneadipamide having repeating polymer chain units having the formula ##STR3##

Claim 18

The track joint (12) of claim 9 wherein the annular sealing member (36) comprises ultra-high molecular weight polyethylene having repeating polymer chain units having the formula --CH.sub.2 --CH.sub.2 ].sub.n.

Claim 19

A seal assembly (10) positioned between first and second relatively movable members (14, 22) for sealing therebetween and cooperating therewith in defining a lubricant holding chamber (35) comprising: an annular sealing member (36) having an integral sealing lip (38) for retaining lubricant in the chamber (35) and for preventing the ingress of contaminants therein, the annular sealing member (36) being of a thermoplastic resin selected from the group consisting of hexamethyleneadipamide containing approximately 18% polytetrafluoroethylene (PTFE) and approximately 2% silicone oil and ultra-high molecular weight polyethylene (UHMW-PE); and load means (42) borne by the first member (14) for urging the sealing lip (38) into sealing engagement with the second member (22).

Claim 20

A seal assembly (10) positioned between first and second relatively movable members (14, 22) for sealing therebetween and cooperating therewith in defining a lubricant holding chamber (35) comprising: an annular sealing member (36) having an integral sealing lip (38) for retaining lubricant in the chamber (35) and for preventing the ingress of contaminants therein, the annular sealing member (36) being of a thermoplastic resin selected from the group consisting of hexamethyleneadipamide containing approximately 18% polytetrafluoroethylene (PTFE) and approximately 2% silicone oil and ultra-high molecular weight polyethylene (UHMW-PE); and load means (42) borne by the first member (14) for urging the sealing lip (38) into sealing engagement with the second member (22).