Plain bearing structure

Abstract

A plain bearing comprises a metal backing, a layer of a porous matrix of sintered metal on the backing and a filled PTFE infiltrated into the interstices of the sintered layer and standing proud of the sintered layer, wherein the PTFE is filled with 1-20% by volume fibrillated aramid fibres and 10-30% by volume glass. The glass is preferably E-glass present as milled filaments of length 0.05-0.30 mm and diameter 0.010-0.020 mm and coated with a silene sizing agent. The fibrillated aramid fibres provide reinforcement and improved load bearing capacity and the glass provides an abrasive filler which abrades asperities on a body and creates a smooth polished surface against which to bear, thereby improving its life. The PTFE preferably also includes ferric oxide and carbon black to about 1.5% and 1.2% by volume respectively which both pigment the polymer and act as an abrasive and lubricant respectively. The carbon black content may be increased to about 10% to provide electrical conductivity. The filler may be prepared as a wet mush or a dry “paper”.

Dependencies are inferred from the claim text.