Seal

Abstract

A seal is provided in which a weir pool is created by overlapping a flange and a weir edge flange. A passage is provided whereby through controlled lubricant leakage a carbon seal is effectively cooled to prevent overheating of a portion adjacent that carbon seal during operation. The weir pool is created by centrifugal forces and the remainder of the lubricant passes over the weir edge in order to lubricate bearings. Thus, the seal allows use of a carbon seal between shafts. Furthermore, at least one shaft can be more conveniently formed integral with a turbine blade assembly.

I claim  
     
         1 . A seal ( 21 ) for rotating shafts, the seal ( 21 ) being formed between inter-engaging shafts ( 22 ,  23 ) appropriately lubricated by a lubricant source ( 34 ), this seal ( 21 ) characterized in that a weir is formed by overlapping flanges ( 20 ,  32 ) with a weir pool ( 33 ) therebetween, one flange ( 40 ) including a passage ( 37 ) for controlled release of lubricant from the weir pool ( 33 ) for a desired purpose.  
     
     
         2 . A seal as claimed in  claim 1  wherein other lubricant in use flows over a weir edge ( 40 ).  
     
     
         3 . A seal as claimed in  claim 1  wherein the overlapping flanges ( 20 ,  32 ) of the shafts ( 22 ,  23 ) are arranged whereby weir pool formation is facilitated in use by co-rotation of the shafts ( 22 ,  23 ).  
     
     
         4 . A seal ( 21 ) as claimed in  claim 1  wherein the desired purpose is as a coolant in use for a seal element ( 30 ) and/or as a lubricant for specific parts of the seal as required.  
     
     
         5 . A seal ( 21 ) as claimed in  claim 4 , wherein the seal element ( 30 ) is a carbon seal extending from one shaft ( 22 ) to the other ( 23 ).  
     
     
         6 . A seal ( 21 ) as claimed in  claim 2  wherein the other lubricant lubricates and/or cools a bearing ( 27 ).  
     
     
         7 . A seal ( 21 ) as claimed in  claim 6 , wherein that bearing ( 27 ) is a roller bearing assembly between the shafts ( 22 ,  23 ).  
     
     
         8 . A seal ( 21 ) as claimed in  claim 1 , wherein the lubricant source ( 34 ) is an oil jet generally propelling oil towards the seal ( 21 ).  
     
     
         9 . A seal ( 21 ) as claimed in  claim 1 , wherein there is indirect feed of oil towards the seal ( 21 ) by scatter deflection and centrifugal collection in the weir pool ( 33 ).  
     
     
         10 . A seal ( 21 ) as claimed in  claim 1 , wherein there is a knife edge seal ( 24 ) between the shafts ( 22 ,  23 ) for configuration and/or to provide auxiliary sealing.  
     
     
         11 . A seal ( 21 ) as claimed in  claim 1 , wherein there is a pressure differential in use across the seal ( 21 ).  
     
     
         12 . A seal ( 21 ) as claimed in  claim 11 , wherein that pressure differential facilitates weir pool ( 33 ) formation.  
     
     
         13 . A seal ( 21 ) as claimed in  claim 10 , wherein the pressure differential facilitates release of lubricant through the passage ( 37 ).  
     
     
         14 . A seal ( 21 ) as claimed in  claim 1 , wherein there is a lubricant gallery ( 38 ) formed between the shafts ( 22 ,  23 ).  
     
     
         15 . A seal ( 21 ) as claimed in  claim 14 , wherein radial conduits ( 43 ,  49 ) for lubricant extend from the gallery ( 38 ).  
     
     
         16 . A seal ( 21 ) as claimed in  claim 1 , wherein there are respective radial conduits ( 43 ,  49 ) for lubricant from the passage ( 34 ) and other lubricant from over the weir edge ( 40 ).  
     
     
         17 . A seal ( 21 ) as claimed in  claim 14 , wherein the gallery ( 38 ) incorporates surface reservoirs ( 42 ,  48 ) for the lubricant from the passage ( 37 ) and/or other lubricant from over the weir edge ( 40 ).  
     
     
         18 . A seal ( 21 ) as claimed in  claim 1 , wherein the weir edge ( 40 ) forms a lip for cascade of other lubricant and flow along a surface ( 46 ) to a sump hole ( 47 ).  
     
     
         19 . A seal ( 21 ) as claimed in, wherein the seal ( 21 ) is located between a high pressure shaft ( 22 ) and a low pressure shaft ( 23 ) of a turbine engine ( 10 ).  
     
     
         20 . A seal ( 21 ) as claimed in  claim 19  wherein the shafts ( 22 ,  23 ) in use co-rotate in the turbine engine.  
     
     
         21 . A turbine engine ( 10 ) incorporating a seal ( 21 ) as claimed in any preceding claim.