Arrangement for mounting two coaxial shaftlines

Abstract

In an assembly with two concentric shafts, one of which projects beyond the other, a seal support sleeve placed between them has a conical shape and bears on a spacer of the external shaft, so that an assembly nut of the forward end is accessible to be unscrewed from the back through the space between the two shafts, thus enabling the external shaft to be disassembled. The invention may be applicable to front bearings of gas turbine high pressure shafts and makes it possible to disassemble the high pressure body from behind, without needing to disassemble equipment, such as a fan on the front of the machine, or hindering the installation of a gear.

1 . An assembly comprising: 
 an internal shaft and an external shaft, said internal and external shafts being coaxial and a forward part of the internal shaft projecting beyond a forward end of the external shaft;    a sleeve surrounding the shafts and holding first and second seals, the first seal sealing a portion of the internal shaft and the second seal sealing a portion of the external shaft;    a first bearing supporting the forward end of the external shaft;    a nut screwed around said forward end for providing a stop for said first bearing; and    a spacer having a first part adjusted around the external shaft and retained between the nut and the first bearing, and a second part extending around the nut on which the second seal sealing with the external shaft rubs.    
   
   
       2 . (canceled)  
   
   
       3 . The assembly according to  claim 1 , further comprising: 
 a gear arranged under the nut, the spacer and the sleeve in a direction substantially perpendicular to both shafts;    a gear support housing surrounding the gear; and    a gear hub holding the gear in said direction, wherein a second bearing for the gear is installed around a shaft of the gear by an ascending displacement from below the housing, and the sleeve comprises a flange in abutment with a part of the housing, the abutment being obtained by a forward displacement of the flange.    
   
   
       4 . The assembly according to  claim 3 , further comprising: 
 a single shell fixed to the housing, in which the second bearing and a third bearing installed around the shaft of the gear are installed.    
   
   
       5 . The assembly according to  claim 1 , wherein a diameter of the second seal is larger than a diameter of the first seal.  
   
   
       6 . The assembly according to  claim 1 , wherein the sleeve is conical.