Mechanical shaft seal

Claim 2

A mechanical shaft seal comprising a housing adapted to be mounted on a machine casing such that one end thereof is exposed to fluid pressure, said housing adapted to surround a rotating shaft extending from the machine casing, said housing having a rotor mounted for rotation therein, said rotor having a bore therethrough to enable said rotor to surround and sealingly engage the shaft for rotation therewith, means defining a nonrotating seal face on said housing interior adjacent the end of the housing exposed to the fluid pressure, a seal ring mounted on said rotor and constrained in fluid sealing engagement therewith for rotation therewith, such seal ring having a seal face in sliding engagement with the non-rotating seal face, said rotor having a pair of opposed faces, spring means disposed between one rotor face and said seal ring to urge the latter axially away from the rotor and into fluid sealing engagement with the nonrotating seal face in opposition to fluid pressure forces tending to separate the seal faces, and bearing means disposed between the other rotor face and a portion of the housing to prevent axial movement of said rotor away from the non-rotating seal face under the influence of said spring means.

Claim 3

The seal according to claim 1 further including adjustment means for moving said bearing means and said rotor in the axial direction to effect there required degree of compression of the spring means to provide a proper fluid sealing effect between the seal faces.

Claim 4

The seal according to claim 2 wherein said spring comprises a Belleville spring washer and wherein said one rotor face is convexly shaped whereby to prevent said Belleville spring from being completely flattened out and thus overstressed when said rotor is moved axially by said adjustment means.

Claim 5

The seal according to claim 2 wherein said adjustment means are accessible from said housing exterior to permit the spring means to be compressed to the required degree without the need of dismantling the seal assembly.

Claim 6

A mechanical shaft seal comprising a housing adapted to be mounted on a machine casing such that one end thereof is exposed to fluid pressure, said housing adapted to surround a rotating shaft extending from the machine casing, said housing having a rotor mounted for rotation therein, said rOtor having a bore therethrough to enable said rotor to surround and sealingly engage the shaft for rotation therewith, means defining a non-rotating seal face on said housing interior adjacent the end of the housing exposed to the fluid pressure, a seal ring mounted on said rotor in fluid sealing engagement therewith for rotation with the rotor, said seal ring having a seal face in sliding engagement with the non-rotating seal face, said rotor having a pair of opposed faces, spring means disposed between one rotor face and said seal ring to urge the latter axially away from the rotor and into fluid sealing engagement with the non-rotating seal face in opposition to fluid pressure forces tending to separate the seal faces, said rotor having an annular ledge portion extending axially away from said one rotor face, said seal ring being mounted on said annular ledge in sealing engagement therewith for axial movement therealong, and axially extending pin means extending between said seal ring and said rotor to cause the seal ring to rotate with the rotor while permitting relative axial movement therebetween.

Claim 7

A mechanical shaft seal comprising a housing adapted to be mounted on a machine casing such that one end thereof is exposed to fluid pressure, said housing adapted to surround a rotating shaft extending from the machine casing, said housing having a rotor mounted for rotation therein, said rOtor having a bore therethrough to enable said rotor to surround and sealingly engage the shaft for rotation therewith, means defining a non-rotating seal face on said housing interior adjacent the end of the housing exposed to the fluid pressure, a seal ring mounted on said rotor in fluid sealing engagement therewith for rotation with the rotor, said seal ring having a seal face in sliding engagement with the non-rotating seal face, said rotor having a pair of opposed faces, spring means disposed between one rotor face and said seal ring to urge the latter axially away from the rotor and into fluid sealing engagement with the non-rotating seal face in opposition to fluid pressure forces tending to separate the seal faces, said rotor having an annular ledge portion extending axially away from said one rotor face, said seal ring being mounted on said annular ledge in sealing engagement therewith for axial movement therealong, and axially extending pin means extending between said seal ring and said rotor to cause the seal ring to rotate with the rotor while permitting relative axial movement therebetween.

Claim 8

The seal according to claim 5 wherein said spring comprises a Belleville washer, and means to prevent the Belleville washer from being completely flattened out and thus overstressed.

Claim 9

A mechanical shaft seal comprising a housing adapted to be mounted on a machine casing such that one end thereof is exposed to fluid pressure, said housing adapted to surround a rotating shaft extending from the machine casing, said housing having a rotor mounted for rotation therein, said rotor having a bore therethrough to enable said rotor to surround and sealingly engage the shaft for rotation therewith, means defining a non-rotating seal face on said housing interior adjacent the end of the housing exposed to the fluid pressure, a seal ring mounted on said rotor for limited axial movement therealong in fluid sealing engagement therewith for rotation with the rotor, such seal ring having a seal face in sliding engagement with the non-rotating seal face, said rotor having a pair of opposed faces, spring means disposed between one rotor face and said seal ring to urge the latter axially away from the rotor and into fluid sealing engagement with the non-rotating seal face in opposition to fluid pressure forces tending to separate the seal faces, and axially extending circumferentially spaced pin means extending between said seal ring and said rotor to cause the seal ring to rotate with the rotor while permitting relative axial movement therebetween.

Claim 10

A mechanical shaft seal comprising a housing adapted to be mounted on a machine casing such that one end thereof is exposed to fluid pressure, said housing adapted to surround a rotating shaft extending from the machine casing, said housing having a rotor mounted for rotation therein, said rotor having a bore therethrough to enable said rotor to surround and sealingly engage the shaft for rotation therewith, means defining a non-rotating seal face on said housing interior adjacent the end of the housing exposed to the fluid pressure, a seal ring mounted on said rotor for limited axial movement therealong in fluid sealing engagement therewith for rotation with the rotor, such seal ring having a seal face in sliding engagement with the non-rotating seal face, said rotor having a pair of opposed faces, spring means disposed between one rotor face and said seal ring to urge the latter axially away from the rotor and into fluid sealing engagement with the non-rotating seal face in opposition to fluid pressure forces tending to separate the seal faces, and axially extending circumferentially spaced pin means extending between said seal ring and said rotor to cause the seal ring to rotate with the rotor while permitting relative axial movement therebetween.

Claim 11

The seal according to claim 7 wherein said spring comprises a Belleville washer, and means to prevent the washer from being completely flattened out and thus overstressed.

Claim 12

The seal according to claim 7 including adjustment means accessible from the exterior of the housing for positioning the rotor at an axial position such as to provide the desired degree of compression of said spring and hence the desired degree of pressure between said sealing faces.

Claim 13

A mechanical shaft seal comprising a housing adapted to be mounted on a machine casing such that one end thereof is exposed to fluid pressure, said housing adapted to surround a rotating shaft extending from the machine casing, said housing having a rotor mounted for rotation therein, said rotor having a bore therethrough to enable said rotor to surround and sealingly engage the shaft for rotation therewith, means defining a non-rotating seal face on said housing interior adjacent the end of the housing exposed to the fluid pressure, a seal ring mounted on said rotor in fluid sealing engagement therewith for rotation with the rotor, said seal ring having a seal face in sliding engagement with the non-rotating seal face, said rotor having a pair of opposed faces, compression spring means disposed between one rotor face and said seal ring to urge the latter axially away from the rotor and into fluid sealing engagement with the non-rotating seal face in opposition to fluid pRessure forces tending to separate the seal faces, said rotor having an annular ledge portion extending axially away from said one rotor face, said seal ring being mounted on said annular ledge in sealing engagement therewith for axial movement therealong, and means arranged between said seal ring and said rotor to cause the seal ring to rotate with the rotor while permitting relative axial movement therebetween.

Claim 14

A mechanical shaft seal comprising a housing adapted to be mounted on a machine casing such that one end thereof is exposed to fluid pressure, said housing adapted to surround a rotating shaft extending from the machine casing, said housing having a rotor mounted for rotation therein, said rotor having a bore therethrough to enable said rotor to surround and sealingly engage the shaft for rotation therewith, means defining a non-rotating seal face on said housing interior adjacent the end of the housing exposed to the fluid pressure, a seal ring mounted on said rotor in fluid sealing engagement therewith for rotation with the rotor, said seal ring having a seal face in sliding engagement with the non-rotating seal face, said rotor having a pair of opposed faces, compression spring means disposed between one rotor face and said seal ring to urge the latter axially away from the rotor and into fluid sealing engagement with the non-rotating seal face in opposition to fluid pRessure forces tending to separate the seal faces, said rotor having an annular ledge portion extending axially away from said one rotor face, said seal ring being mounted on said annular ledge in sealing engagement therewith for axial movement therealong, and means arranged between said seal ring and said rotor to cause the seal ring to rotate with the rotor while permitting relative axial movement therebetween.

Claim 15

The seal according to claim 10 wherein said spring comprises a Belleville washer, and means to prevent the Belleville washer from being completely flattened out and thus overstressed.

Claim 16

A mechanical seal according to claim 10 further including bearing means interposed between said housing and said rotor to prevent movement of the rotor away from said non-rotating seal face whereby to assist in maintaining the seal faces in said sealing engagement.

Claim 17

The seal according to claim 12 including adjustment means associated with said bearing means for shifting same together with said rotor in the axial direction to compress the spring means and provide the desired degree of pressure between said seal faces.

Claim 18

The seal according to claim 12 wherein said rotor further includes a collar portion, said rotor also having a barrel portion, said barrel portion and said ledge portion extending in opposite directions from the collar portion, said bearing means comprising a thrust bearing surrounding said barrel means and disposed between an end wall of the housing and one side of said collar portion.

Claim 19

The seal according to claim 14 wherein the means to cause rotation of the rotor with the seal ring comprises axially extending circumferentially spaced pin means extending from the seal ring into said rotor to transmit rotary motion of the latter to the seal ring.

Claim 20

The seal according to claim 15 including adjustment means for positioning said thrust bearing and said rotor at an axial position such as to provide the desired degree of compression of said spring means and hence the desired degree of pressure between said sealing faces.

Claim 21

The seal according to claim 15 wherein said rotor has a bore extending axially therethrough and having a diameter chosen in accordance with the diameter of the shaft.