Bellows type fluid seal

Claim 2

A diaphragm bellows type mechanical seal comprising: a first sealing ring structure provided with a first annular lapped sealing face on its front end, a second sealing ring structure provided with a second complementary annular lapped sealing face on its front end, an extendible bellows means hermetically connected to the rear end of said second sealing ring structure and adapted to force said lapped sealing faces together in sealing relation responsive to fluid pressures of different magnitudes applied to the opposite sides of said bellows means, said bellows means comprising a plurality of axially aligned, annular, flexible metal diaphragm portions meeting at acute angles along successive inner and outer diamters, radial support means incorporated with said second sealing ring structure which is adapted to modify the resistance to radial elastic deflection of said second sealing ring structure caused by application of fluid pressures of different magnitudes to the inner and outer peripheries of said second sealing ring structure, said radial support means providing said second sealing ring structure with a greater resistance to radial elastic deflection at its front end near said second lapped sealing face than at its rear end so that said second sealing ring structure, with a higher fluid pressure applied to its outer periphery than to its inner periphery, will deflect radially inwardly to a grEater extent at its rear end than at its front end thereby warping said second lapped sealing face into a surface configuration wherein the outer circumference thereof is displaced in a direction axially away from the direction of sealing engagement with said first lapped sealing face, the major portion of the area of said second lapped sealing face being disposed radially within the mean diameter of said bellows means, and the remainder of said area being a substantial portion thereof, being disposed radially outside of said mean diameter.

Claim 3

A diaphragm bellows type mechanical seal comprising: a first sealing ring structure provided with a first annular lapped sealing face on its front end, a second sealing ring structure provided with a second complementary annular lapped sealing face on its front end, an extendible bellows means hermetically connected to the rear end of said second sealing ring structure and adapted to force said lapped sealing faces together in sealing relation responsive to fluid pressures of different magnitudes applied to the opposite sides of said bellows means, said bellows means comprising a plurality of axially aligned, annular, flexible metal diaphragm portions meeting at acute angles along successive inner and outer diameters, radial support means incorporated with said second sealing ring structure which is adapted to modify the resistance to radial elastic deflection of said second sealing ring structure caused by application of fluid pressures of different magnitudes to the inner and outer peripheries of said second sealing ring structure, said radial support means providing said second sealing ring structure with a greater resistance to radial elastic deflection at its front end near said second lapped sealing face than at its rear end so that said second sealing ring structure, with a given fluid pressure difference applied radially thereacross, will deflect radially to a greater extent at its rear end than at its front end thereby warping said second lapped sealing face into a surface configuration wherein that circumference thereof that is adjacent to the higher pressure fluid is displaced in a direction axially away from the direction of sealing engagement with said first lapped sealing face, the major portion of the area of said second lapped sealing face being disposed on the lower fluid pressure side of the mean diameter of said bellows means and the remainder of said area, being a substantial portion thereof, being disposed on the higher fluid pressure side of said mean diameter.

Claim 4

A diaphragm bellows type mechanical seal comprising: a first sealing ring structure provided with a first annular lapped sealing face on its front end, a second sealing ring structure provided with a second complementary annular lapped sealing face on its front end, an extendible bellows means hermetically connected to the rear end of said second sealing ring structure and adapted to force said lapped sealing faces together in sealing relation responsive to fluid pressures of different magnitudes applied to the opposite sides of said bellows means, said bellows means comprising a plurality of axially aligned, annular, flexible metal diaphragm portions meeting at acute angles along successive inner and outer diameters, radial support means incorporated with said second sealing ring structure which is adapted to modify the resistance to radial elastic deflection of said second sealing ring structure caused by application of fluid pressures of different magnitudes to the inner and outer peripheries of said second sealing ring structure, said radial support means providing said second sealing ring structure with a greater resistance to radial elastic deflection at its front end near said second lapped sealing face than at its rear end so that said second sealing ring structure, with a given fluid pressure difference applied radially thereacross, will deflect radially to a greater extent at its rear end than at its front end thereby warping said second lapped sealing face into a surface configuration wherein that circumference thereof that is adjacent to the higher pressure fluid is displaced in a direction axially away from the direction of sealing engagement with said first lapped sealing face, the major portion of the area of said second lapped sealing face being disposed on the lower fluid pressure side of the mean diameter of said bellows means and the remainder of said area, being a substantial portion thereof, being disposed on the higher fluid pressure side of said mean diameter.

Claim 5

The bellows seal of claim 1 wherein said second sealing ring structure comprises a sealing ring of low elastic strength mounted within a ferrule of high elastic strength, said ferrule including a deflection reinforcing member disposed at the front of said second sealing ring structure near said second sealing face.

Claim 6

The bellows seal of claim 1 wherein said second lapped sealing face is comprised of carbon and said first lapped sealing face is comprised of a hard metal alloy.

Claim 7

The bellows seal of claim 1 wherein said second sealing ring structure and said bellows means are adapted for mounting on a rotatable shaft and said first sealing ring structure is adapted for mounting on a stationary housing.