Shaft seal

Claim 2

A seal for providing a seal between a housing and a shaft which passes therethrough, said sealing including: an annular seal member constructed from a relatively resilient material, said seal member when unstressed having an outer diameter surface and a back surface for sealing engagement with the housing, a front surface having an abutment portion and a circular notch of V-shape cross-section defined therein, and an inner surface having a cylindrical portion of a diameter about the diameter of the shaft and a frustro-conical portion extending from said cylindrical portion to said back surface, said V-shaped notch and said frustro-conical portion defining a sealing lip tipped by said cylindrical portion; an annular spacer member constructed from a relatively rigid material, said spacer member having an inner diameter larger than the shaft diameter, front and back side faces with said front face including an abutment portion, and a circular protrusion having a semi-toroidal nose which extends from said front face; and bias means for applying force against the back surface of said spacer member, said bias means forcing said protrusion into said V-shaped notch to press said seal member against the housing and said lip against the shaft, said abutment portions of said spacer member front face and said seal member front face being positioned to come into abutment when a predetermined force is applied to said spacer by said bias means, any additional force being absorbed by the resilience of said seal member.

Claim 3

The seal defined in claim 1 wherein said V-shaped notch has side walls which are at about 30* angles to said inner surface and wherein said frustro-conical portion is at an angle of about 20* to said inner surface.

Claim 4

Sealing means including: an annular shaft; a housing about a portion of said shaft, said housing having an interior cylindrical surface in axial alignment with said shaft and an adjacent flat surface perpendicular thereto to define an annular hole about a small portion of said shaft; an annular seal member constructed from relatively resilient material and when unstressed having for an outer diameter and a back surface for sealing engagement with said housing, a front surface having an abutment portion and a circular notch of V-shape cross-section defined therein, and an inner surface having a cylindrical portion of a diameter about the diameter of said shaft and a frustro-conical portion extending from said cylindrical portion to said back surface, said V-shaped notch and said frustro-conical portion defining a sealing lip tipped by said cylindrical portion; an annular spacer member constructed from relatively rigid material and having an inner diameter larger than said shaft diameter, front and back side faces with said front face including an abutment portion, and a circular protrusion having a semi-toroidal nose which extends outwardly from said face; and bias means for applying force against the back surface of said spacer member, said bias means forcing said protrusion into said V-shaped notch to press said outer diameter and back surfaces of said seal member against said housing and said sealing lip against said shaft, said abutment portions of said spacer member front face and said seal member front surface being positioned to come into abutment when a predetermined force is applied to said spacer by said bias means, any additional force being absorbed by the resilience of said seal member.

Claim 5

Sealing means including: an annular shaft; a housing about a portion of said shaft, said housing having an interior cylindrical surface in axial alignment with said shaft and an adjacent flat surface perpendicular thereto to define an annular hole about a small portion of said shaft; an annular seal member constructed from relatively resilient material and when unstressed having for an outer diameter and a back surface for sealing engagement with said housing, a front surface having an abutment portion and a circular notch of V-shape cross-section defined therein, and an inner surface having a cylindrical portion of a diameter about the diameter of said shaft and a frustro-conical portion extending from said cylindrical portion to said back surface, said V-shaped notch and said frustro-conical portion defining a sealing lip tipped by said cylindrical portion; an annular spacer member constructed from relatively rigid material and having an inner diameter larger than said shaft diameter, front and back side faces with said front face including an abutment portion, and a circular protrusion having a semi-toroidal nose which extends outwardly from said face; and bias means for applying force against the back surface of said spacer member, said bias means forcing said protrusion into said V-shaped notch to press said outer diameter and back surfaces of said seal member against said housing and said sealing lip against said shaft, said abutment portions of said spacer member front face and said seal member front surface being positioned to come into abutment when a predetermined force is applied to said spacer by said bias means, any additional force being absorbed by the resilience of said seal member.

Claim 6

The sealing means defined in claim 3 wherein said bias means are a spring mounted concentrically about said shaft and caged between said spacer member and said shaft.

Claim 7

The sealing means defined in claim 3 wherein said bias means are a spring mounted concentrically about said shaft and caged between said spacer member and said housing.