Shaft seal assembly

Abstract

An illustrative embodiment of a shaft seal assembly generally includes a fixed stator, a floating stator, and a sealing member. In the illustrative embodiment the fixed stator may be formed with one or more fluid conduits that are in fluid communication with one or fluid conduits formed in the floating stator. The fluid conduits in the floating stator may be in fluid communication with one or more fluid conduits formed in a sealing member. A rotational interface may exist between the sealing member and a shaft, and the various fluid conduits may be configured to create a fluid barrier at that interface. Other embodiments of a shaft seal assembly may create a fluid barrier at a rotational interface between a rotor and a floating stator.

What is claimed is: 
     
         1 . A method of creating a pressurized fluid barrier between a shaft and a sealing member at an interface therebetween, said method comprising the steps of:
 a. engaging a fixed stator with a housing, wherein said shaft protrudes from and is rotatable with respect to said housing, and wherein said fixed stator comprises:
 i. an annular recess along a portion of a radial-interior surface of said fixed stator, wherein said annular recess includes first and second radially oriented surfaces and a circumferential axially oriented surface; 
 ii. an inlet extending from a radial-exterior surface of said fixed stator to said annular recess in a generally radial direction, wherein said fixed stator is engaged with a housing at an aperture of said housing, wherein a shaft rotatable with respect to said housing extends outward from said aperture; 
   b. positioning said shaft sealing member in said annular recess, wherein a predetermined clearance in a radial dimension between a radial-exterior surface said shaft sealing member and said radial-interior surface of said annular recess in said fixed stator is equal to an amount of allowed relative movement between said shaft sealing member and said fixed stator in said radial dimension, and wherein said shaft sealing member comprises:
 i. a floating stator having a radial-interior surface that is substantially concave in shape, wherein a pin recess is formed in said floating stator and extends from said radial-exterior surface of said shaft sealing member to said radial-interior surface of said floating stator; 
 ii. a sealing member, wherein said sealing member includes a radial-exterior surface with a substantially convex shape that corresponds to the radial-interior surface of said floating stator so as to create a spherical interface therebetween, wherein said sealing member is positioned adjacent said shaft extending from said housing; and, 
 iii. a plurality of radial bores extending from said radial-exterior surface of said sealing member to said radial-interior surface thereof; and, 
   c. providing a pressurized sealing fluid to said inlet formed in said fixed stator, wherein said pressurized sealing fluid travels through said inlet to said pin recess formed in said floating stator, through said pin recess to said sealing member, and through said plurality of radial bores formed in said sealing member to form a pressurized fluid barrier between said radial-interior surface of said sealing member and said shaft.   
     
     
         2 . The method according to  claim 1  wherein said plurality of radial bores is further defined as 16 radial bores evenly spaced about the periphery of said sealing member. 
     
     
         3 . The method according to  claim 1  wherein said plurality of radial bores is further defined as being arranged in corresponding pairs, and wherein said plurality of radial bores are evenly spaced about the periphery of said sealing member. 
     
     
         4 . The method according to  claim 1  wherein said plurality of radial bores is further defined as being unevenly spaced about the periphery of said sealing member. 
     
     
         5 . The method according to  claim 1  wherein said fixed stator further comprises an inlet, and wherein said pressurized sealing fluid is provided to said inlet. 
     
     
         6 . The method according to  claim 5  wherein said floating stator further comprises a fluid conduit, wherein said fluid conduit is in fluid communication with both said inlet and said spherical interface. 
     
     
         7 . The method according to  claim 6  wherein said fluid conduit in said floating stator is further defined as being a second pin recess. 
     
     
         8 . The shaft seal assembly according to  claim 7  wherein said pin recess further comprises a pin recess enlarged portion on a radially inward portion thereof adjacent said sealing member. 
     
     
         9 . The method according to  claim 1  wherein said sealing member further comprises a recess formed in said radial-exterior surface thereof, wherein said recess does not extend to said radial-interior surface of said sealing member. 
     
     
         10 . The method according to  claim 9  further comprising a pin, wherein a first portion of said pin is positioned in said pin recess and a second portion of said pin is positioned in said recess. 
     
     
         11 . The shaft seal assembly according to  claim 1 , wherein said annular recess is defined by a first and a second radially oriented surface and a circumferential axially oriented surface. 
     
     
         12 . The shaft seal assembly according to  claim 11  wherein said fixed stator is further defined as comprising a main body and a face plate, wherein said face plate is selectively engageable with said main body, and wherein an interior surface of said face plate forms said first radially oriented surface of said annular recess. 
     
     
         13 . The shaft seal assembly according to  claim 12  wherein said face plate is further defined as having a face plate pin recess formed in said interior surface thereof. 
     
     
         14 . The shaft seal assembly according to  claim 13  wherein said face plate is further defined as having a face plate seal groove formed in said interior surface thereof, wherein a seal is positioned in said face plate seal groove. 
     
     
         15 . The shaft seal assembly according to  claim 14  wherein said floating stator is further defined as having a floating stator seal groove formed in said radial-interior surface thereof, wherein a seal is positioned in said floating stator seal groove.