Composite dry sliding bearings – maintenance-free and space-saving

Chemical propertiesThe chemical resistance of SKF compositedry sliding bearings is primarilydetermined by the chemical resistanceof the steel backing and the sinteredtin bronze layer, as the sliding (covering)layers are chemically resistant tomany substances. The covering layerof the PTFE composite material is virtuallyinert because of its PTFE content,although at elevated temperaturesmolten alkali metals and freefluorine will attack it. The acetal resincovering layer of the POM compositebearings is largely resistant to organicsubstances.At room temperature the sintered tinbronze structure has good resistanceto sea water, steam, atmospheric influences,salt solutions and sulphuricacid, but not to oxidising acids ormedia containing ammonia.All exposed surfaces of the steelbacking are electrolytically tin platedbut this gives only limited protectionagainst corrosion in most applications.In cases where the bearings are to beexposed to corrosive media, or wherethere is a danger of corrosion in thecontact between the steel backing andthe housing material, the backing canbe protected by a nickel, chromium orzinc coating applied electrolytically.Further details can be supplied onrequest.Valid for steel housings with D G /D = 2DiagramDiagram12Requisiteinterference ofthe mandrelGuideline valuesfor coefficient offriction of PTFEcomposite drysliding bearings9