Forming a bearing

Abstract

A method of forming a bearing comprising adding an aqueous colloidal dispersion of at least one particulate material to an aqueous dispersion of polytetrafluoroethylene. The method also comprises mixing the dispersions for a period sufficient to allow the polytetrafluoroethylene to coagulate to form a mush, spreading the mush onto a support, and curing the mush to form a bearing lining layer on the support.

1 . A method of forming a bearing comprising adding an aqueous colloidal dispersion of at least one particulate material to an aqueous dispersion of polytetrafluoroethylene, the method also comprising mixing the dispersions for a period sufficient to allow the polytetrafluoroethylene to coagulate to form a mush, spreading the mush on to a support, and curing the mush to form a bearing lining layer on the support.  
     
     
         2 . A method according to  claim 1 , characterised in that the particles of the particulate material have their median dimension between 1 nanometer and 100 nanometers.  
     
     
         3 . A method according to  claim 2 , characterised in that the median dimension is between 5 nanometers and 30 nanometers.  
     
     
         4 . A method according to any one of  claims 1  to  3 , characterised in that the particulate material is selected from the group consisting of metals, metal oxides, metal sulphides, metal fluorides, metal carbonates, metal phosphates and silica.  
     
     
         5 . A method according to any one of  claims 1  to  4 , characterised in that additional fillers are included in the aqueous dispersion of polytetrafluoroethylene.  
     
     
         6 . A bearing formed by a method according to any one of  claims 1  to  5 , comprising a support which comprises a sintered bronze support, the bearing also comprising a lining layer which is impregnated into the support and stands proud thereof, the lining layer comprising polytetrafluoroethylene in which particulate material is dispersed, characterised in that the particulate material has a median particle dimension of between 1 nanometer and 100 nanometers.  
     
     
         7 . A bearing according to  claim 6 , characterised in that the particulate material is alumina.