Brush seals

Abstract

According to the present invention there is provided an annular brush seal comprising a bristle pack, the bristle pack having an upstream face, a downstream face and a sealing face, wherein the sealing face is provided with an annular chamfered relief extending from a location intermediate the upstream face and the downstream face and terminating at the upstream face. The revised geometry providing more consistent performance through the life of the brush seal. Also provided is a method for the manufacture of such a seal.

1  An annular brush seal comprising a bristle pack, the bristle pack having an upstream face, a downstream face and a sealing face, wherein there is formed between the upstream face and the sealing face an annular relief in the form of a chamfer that extends from a location on the upstream face to a location on the sealing face intermediate the upstream face and the downstream face.  
     
     
         2  An annular brush seal as claimed in  claim 1 , wherein the annular relief is formed on the bristle pack coaxial with, and at a substantially constant angle to the sealing face.  
     
     
         3  An annular brush seal as claimed in  claim 2  wherein the angle of the chamfer to the sealing face lies between 40° and 50°.  
     
     
         4  A method for producing an annular brush seal comprising a bristle pack, the bristle pack having an upstream face, a downstream face and a sealing face, wherein there is formed between the upstream face and the sealing face an annular relief in the form of a chamfer that extends from a location on the upstream face to a location on the sealing face intermediate the upstream face and the downstream face.  
     
     
         5  A method as claimed in  claim 4  comprising the further steps of using grinding means to form the annular relief in the bristle pack.  
     
     
         6  A method as claimed in  claim 5  wherein the grinding means comprises a grinding wheel with a conical grinding face.  
     
     
         7  A method as claimed in  claim 6  wherein the grinding means comprises a grinding wheel with a first cylindrical grinding face and a second conical grinding face.