Stabilising band for a roller assembly

Abstract

The invention relates to a stabilising band for a roller assembly of the type used in the drilling industry. The roller assembly includes a roller pin mounted within a bore of a roller and the stabilising band is configured so as to fit tightly about the roller pin with a minimal running fit and within an annular groove formed in a wall of the bore of the roller.

1 - 15 . (canceled)  
   
   
       16 . A stabilizing band for a roller assembly, the roller assembly having a roller pin mounted within a bore of a roller, the stabilizing band being configured so as to fit tightly about the roller pin with a minimal running fit and within an annular groove formed in a wall of the bore of the roller, said stabilizing band being broken so as to provide a gap between respective first and second ends of the stabilizing band.  
   
   
       17 . A stabilizing band according to  claim 16  wherein the first and second ends each terminate at an angle of about 45°.  
   
   
       18 . A stabilizing band according to  claim 16  wherein the gap extends for approximately 15° of arc of the stabilizing band.  
   
   
       19 . A stabilizing band according to  claim 16  wherein it is configured to float within the annular groove so that it may either be rotatable with the roller pin or with the roller.  
   
   
       20 . A stabilizing band according to  claim 16  made of a material that is reasonably hard and has a relatively low coefficient of friction.  
   
   
       21 . A stabilizing band according to  claim 20  wherein the material has a Shore D hardness of about 67.  
   
   
       22 . A stabilizing band according to  claim 20  wherein the material has a static coefficient of friction of about 0.09.  
   
   
       23 . A stabilizing band according to  claim 20  wherein the material has dynamic coefficient of friction of about 0.13.  
   
   
       24 . A stabilizing band according to  claim 16  made from a fluoropolymer material.  
   
   
       25 . A stabilizing band according to  claim 24  wherein the fluoropolymer material includes a filler.  
   
   
       26 . A stabilizing band according to  claim 25  wherein the filler is a glass, bronze or nickel filler.  
   
   
       27 . A stabilizing band according to  claim 16  made from a bronze filled PTFE.  
   
   
       28 . A roller assembly including a roller pin, a roller, at least one seal and at least one stabilizing band configured to fit tightly about the roller pin with a minimal running fit and within an annular groove formed in a wall of a bore of the roller, said stabilizing band being broken so as to provide a gap between respective first and second ends of the stabilizing band.  
   
   
       29 . A roller assembly according to  claim 28  wherein the roller pin is fixed and the roller is arranged to rotate thereabout.  
   
   
       30 . A roller assembly according to  claim 28  including two seals and two stabilizing bands.