Reduced pressure load finger seal assembly

Abstract

A sealing assembly for achieving a fluid seal between a rotatable shaft and a housing circumscribing the rotatable shaft to inhibit fluid leakage therebetween a high pressure fluid region and a relatively lower pressure fluid region. The sealing assembly includes at least one primary seal, comprising an axial stack of a plurality of diaphragm members, including an upstream diaphragm and a downstream diaphragm. A plurality of finger seal plates are positioned between the upstream diaphragm and the downstream diaphragm. The plurality of diaphragm members define a passageway in fluid communication with the high pressure fluid region and a low pressure fluid region. The sealing assembly includes at least one secondary seal positioned within the passageway and configured to convert fluid from a high pressure axial pressure balance to a low pressure axial pressure balance thereby reducing a radially inward pressure load.

1 . A sealing assembly for disposition in cooperation with a body defining a bore and a shaft member rotatably received in the bore, and to inhibit fluid leakage between a high pressure fluid region and a relatively lower pressure fluid region, the sealing assembly comprising:
 at least one primary seal comprising an axial stack of a plurality of diaphragm members, the axial stack including an upstream diaphragm and a downstream diaphragm, a plurality of finger seal plates sandwiched between the upstream diaphragm and the downstream diaphragm;   a passageway formed in the axial stack of the plurality of diaphragm members and in fluid communication with the high pressure fluid region and the lower pressure fluid region, wherein the passageway is comprised of at least one radial passage and at least one axial passage; and   at least one secondary seal positioned within the passageway and configured to convert fluid from a high pressure axial pressure balance to a low pressure axial pressure balance thereby reducing a radially inward pressure load.   
   
   
       2 . The sealing assembly of  claim 1 , wherein the at least one secondary seal is formed by one of a wire seal ring, by positioning the finger seal plates in close tolerance, a piston ring and a spring, a “C” shaped seal, or a tapered piston ring. 
   
   
       3 . The sealing assembly of  claim 2 , wherein the wire seal ring is comprised of a 0.040″ wire. 
   
   
       4 . The sealing assembly of  claim 1 , further including an intermediate diaphragm positioned between the upstream diaphragm and the downstream diaphragm, a first plurality of finger seal plates sandwiched between the upstream diaphragm and the intermediate diaphragm, and a second plurality of finger seal plates sandwiched between the downstream diaphragm and the intermediate diaphragm. 
   
   
       5 . The sealing assembly of  claim 1 , wherein the plurality of finger seal plates include a circumferentially continuous band portion and a plurality of uniformly spaced and angulated integral finger portions extending radially inward from the circumferentially continuous band portion and circumscribing the shaft member. 
   
   
       6 . The sealing assembly of  claim 5 , wherein each finger portion being of substantially the same width and defining respective uniform gaps between adjacent finger portions, an arcuate end edge surface of each of the finger portions sealingly and movably engaging the shaft member 
   
   
       7 . The sealing assembly of  claim 1 , further including an annular housing defining an annular portion and a seal retention flange wherein a radially outer portion of each of the plurality of diaphragm members is received therein. 
   
   
       8 . The sealing assembly of  claim 1 , further including a high pressure hydrostatic force in fluidic communication with the high pressure fluid region and the plurality of finger seal plates. 
   
   
       9 . The sealing assembly of  claim 8 , further including an orifice plate and a sealed cavity, wherein the high pressure hydrostatic force is fed to the sealed cavity via a fluidic pressure passage. 
   
   
       10 . A sealing assembly for disposition in cooperation with a body defining a bore and a shaft member rotatably received in the bore, and to inhibit fluid leakage between a high pressure fluid region and a relatively lower pressure fluid region, the sealing assembly comprising:
 an axial stack of a plurality of diaphragm members, the axial stack including an upstream diaphragm and a downstream diaphragm, a plurality of finger seal plates sandwiched between the upstream diaphragm and the downstream diaphragm, wherein the plurality of finger seal plates include a circumferentially continuous band portion and a plurality of uniformly spaced and angulated integral finger portions extending radially inward from the circumferentially continuous band portion and circumscribing the shaft member;   a passageway formed in the axial stack of the plurality of diaphragm members and in fluid communication with the high pressure fluid region and the lower pressure fluid region, wherein the passageway is comprised of at least one radial passage and at least one axial passage; and   at least one secondary seal positioned within the passageway and configured to convert fluid from a high pressure axial pressure balance to a low pressure axial pressure balance thereby reducing a radially inward pressure load.   
   
   
       11 . The sealing assembly of  claim 10 , wherein at least one secondary seal is a wire seal piston ring is comprised of a 0.040″ wire. 
   
   
       12 . The sealing assembly of  claim 10 , further including an intermediate diaphragm positioned between the upstream diaphragm and the downstream diaphragm, a first plurality of finger seal plates sandwiched between the upstream diaphragm and the intermediate diaphragm, and a second plurality of finger seal plates sandwiched between the downstream diaphragm and the intermediate diaphragm. 
   
   
       13 . The sealing assembly of  claim 10 , further including an annular housing defining an annular portion and a seal retention flange wherein a radially outer portion of each of the plurality of diaphragm members is received therein. 
   
   
       14 . The sealing assembly of  claim 10 , further including a high pressure hydrostatic force in fluidic communication with the high pressure fluid region and at least one of the plurality of finger seal plates. 
   
   
       15 . The sealing assembly of  claim 14 , further including an orifice plate and a sealed cavity, wherein the high pressure hydrostatic force is fed to the sealed cavity via a fluidic pressure passage. 
   
   
       16 . A sealing assembly for disposition in cooperation with a body defining a bore and a shaft member rotatably received in the bore, and to inhibit fluid leakage between a high pressure fluid region and a relatively lower pressure fluid region, the sealing assembly comprising:
 an axial stack of a plurality of diaphragm members, the axial stack including an upstream diaphragm and a downstream diaphragm, a plurality of finger seal plates sandwiched between the upstream diaphragm and the downstream diaphragm;   a passageway formed in the axial stack of the plurality of diaphragm members and in fluid communication with the high pressure fluid region and the lower pressure fluid region, wherein the passageway is comprised of at least one radial passage and at least one axial passage; and   a wire seal piston ring positioned within the passageway and configured to convert fluid from a high pressure axial pressure balance to a low pressure axial pressure balance thereby reducing a radially inward pressure load.   
   
   
       17 . The sealing assembly of  claim 16 , wherein the wire seal piston ring is comprised of a 0.040″ wire. 
   
   
       18 . The sealing assembly of  claim 16 , wherein the plurality of finger seal plates include a circumferentially continuous band portion and a plurality of uniformly spaced and angulated integral finger portions extending radially inward from the circumferentially continuous band portion and circumscribing the shaft member. 
   
   
       19 . The sealing assembly of  claim 16 , further including a high pressure hydrostatic force in fluidic communication with the high pressure fluid region and the plurality of finger seal plates. 
   
   
       20 . The sealing assembly of  claim 19 , further including an orifice plate and a sealed cavity, wherein the high pressure hydrostatic force is fed to the sealed cavity via a fluidic pressure passage.