Rotary machine shaft seal

Claim 2

In a rotary machine that includes a housing, a shaft carried for rotation and extending from said housing and a shaft seal carried by said housing in sealing engagement with said shaft to prevent leakage of fluid along said shaft, the improvement wherein said shaft seal comprises: an annular shell of rigid construction adapted for mounting on said housing surrounding said shaft and spaced radially therefrom, annular sealing means carried within said shell and extending radially inwardly therefrom into self-biased rotary sealing engagement with said shaft, and pressure relief valve means that includes at least one opening that extends radially through said shell adjacent to but spaced from said sealing means, and a resilient band surrounding said shell externally of said shell and overlying said opening such that fluid pressure within said shell through said opening urges said band away from said opening.

Claim 3

The machine set forth in claim 1 wherein said shaft seal includes first and second said sealing means spaced from each other along said shaft for self-biased sealing engagement with said shaft independently of each other, said pressure relief valve means being disposed between said sealing means.

Claim 4

The machine set forth in claim 2 wherein said shell has a radially inwardly extending channel positioned between said sealing means, said at least one opening extending through said shell within said channel and said resilient band being disposed within said channel.

Claim 5

The machine set forth in claim 3 wherein said shell includes a pair of inwardly turned flanges on opposed sides of said channel, said first and second sealing means being mounted between said channel and respective one of said flanges.

Claim 6

The machine set forth in claim 4 wherein each of said annular sealing means comprises a V-shaped seal of elastomeric construction and a garter spring urging one leg of each said V-shaped seal into sealing engagement with said shaft.

Claim 7

The machine set forth in claim 5 wherein said at least one opening comprises a plurality of said openings circumferentially spaced around said shell.

Claim 8

The machine set forth in claim 1 wherein said shell has a first portion radially surrounding said annular sealing means and a second portion stepped radially inwardly from said first portion, said at least one opening extending through said second portion and said band being disposed externally of said second portion.

Claim 9

The machine set forth in claim 7 wherein said at least one opening comprises a plurality of said openings circumferentially spaced around said shell.

Claim 10

In a rotary machine that includes a housing, a shaft rotatably extending from said housing, an opening in said housing surrounding said shaft and coaxially spaced therefrom, a fluid passage extending from said opening to externally of said housing, and a shaft seal within said opening for preventing leakage of fluid along said shaft, the improvement wherein said shaft seal comprises: an annular shell of rigid construction separate from said housing and removably received within said housing opening surrounding said shaft, first and second annular sealing means mounted within said shell spaced from each other along said shaft and extending radially inwardly from said shell for self-biased rotary sealing engagement with said shaft independently of each other, and pressure relief valve means comprising at least one opening extending radially through said shell between said annular sealing means and an elastic band resiliently surrounding said shell externally of said at least one opening such that pressure of fluid between said sealing means urges said band away from said shell to permit flow of such fluid through said at least one opening into said housing opening and thence through said passage.

Claim 11

In a rotary machine that includes a housing, a shaft rotatably extending from said housing, an opening in said housing surrounding said shaft and coaxially spaced therefrom, a fluid passage extending from said opening to externally of said housing, and a shaft seal within said opening for preventing leakage of fluid along said shaft, the improvement wherein said shaft seal comprises: an annular shell of rigid construction separate from said housing and removably received within said housing opening surrounding said shaft, first and second annular sealing means mounted within said shell spaced from each other along said shaft and extending radially inwardly from said shell for self-biased rotary sealing engagement with said shaft independently of each other, and pressure relief valve means comprising at least one opening extending radially through said shell between said annular sealing means and an elastic band resiliently surrounding said shell externally of said at least one opening such that pressure of fluid between said sealing means urges said band away from said shell to permit flow of such fluid through said at least one opening into said housing opening and thence through said passage.

Claim 12

The machine set forth in claim 9 wherein said shell has a radially inwardly extending channel positioned between said sealing means, said at least one opening extending through said shell within said channel and said resilient band being disposed within said channel.

Claim 13

The machine set forth in claim 10 wherein said shell includes a pair of inwardly turned flanges on opposed sides of said channel, said first and second sealing means being mounted between said channel and respective ones of said flanges.

Claim 14

The machine set forth in claim 10 wherein said at least one opening comprises a plurality of said openings circumferentially spaced around said shell.

Claim 15

A shaft seal cartridge assembly for use in a shaft opening of predetermined diameter, said assembly comprising: an annular shell of rigid construction having an outer diameter to be received with said shaft opening, first and second annular resilient sealing means spaced from each other and mounted within said shell for self-biased rotary sealing engagement with a shaft independently of each other, at least one opening extending radially through said shell between said sealing means, and an elastic band resiliently surrounding said shell in elastic tension externally of said shell and overlying said at least one opening.

Claim 16

A shaft seal cartridge assembly for use in a shaft opening of predetermined diameter, said assembly comprising: an annular shell of rigid construction having an outer diameter to be received with said shaft opening, first and second annular resilient sealing means spaced from each other and mounted within said shell for self-biased rotary sealing engagement with a shaft independently of each other, at least one opening extending radially through said shell between said sealing means, and an elastic band resiliently surrounding said shell in elastic tension externally of said shell and overlying said at least one opening.

Claim 17

The assembly set forth in claim 13 wherein said shell has a radially inwardly extending channel positioned between said sealing means, said at least one opening extending through said shell within said channel and said resilient band being disposed within said channel.

Claim 18

The assembly set forth in claim 14 wherein said shell includes a pair of inwardly turned flanges on opposed sides of said channel, said first and second sealing means being mounted between said channel and respective one of said flanges.

Claim 19

The assembly set forth in claim 15 wherein each of said annular sealing means comprises a V-shaped seal of elastomeric construction and a garter spring urging one leg of each said V-shaped seal into sealing engagement with said shaft.

Claim 20

The assembly set forth in claim 13 wherein said at least one opening comprises a plurality of said openings circumferentially spaced around said shell.