Study On Surface Modification Methods Of Spherical Plain Bearings

Spherical plain bearings belong to a kind of sliding bearing, because of those ownstructural features, with large carrying capacity, good resistance to impact and abrasionresistance, which are widely used in aerospace, engineering machinery and railwaylocomotive, etc. With some advanced areas of spherical plain bearing demandincreased, the operational properties and tribological properties of spherical plainbearings have great demand. The spherical plain bearing with steel/steel friction pairare easy to cause the friction coefficient and wear increases, even failure which isinside and outside ring mating surface with the high frequency, big torque and extremeambient conditions. Therefore, looking for a new type of surface modification methodto improve the tribological properties of spherical plain bearing with steel/steel frictionpair is particularly important. Based on the bond solid lubricant coating method, thesolid lubrication coating of spherical plain bearing inner ring appearance surfacewhich are used inorganic phosphate as binder, MoS2or graphite as solid lubricant areprepared by spraying method, cohesiveness and the properties of friction and wear ofself-lubrication coating are respectively tested by INSTRON tensile and compressiontesting machine and HSR-2M speed reciprocating friction and wear tester, The effectsof different spray gun pressure, different coating compoundings and swingingconditions on the cohesiveness and tribological properties of spherical plain bearingsare investigated. The main research works are as follows.The compounding of MoS2and graphite self-lubricating composite coating wereresearched, which were prepared by spraying method in bearing steel surface. A set ofcompounding was designed by selecting three kinds of spray gun pressures, andchanging the percentage of graphite and MoS2. The effects of different spray gunpressures and different ratio on the bonding and tribological properties of compositecoating were investigated through bonding and tribological properties of test.Applying this method of surface modification on the spherical plain bearings, a large number of tribological properties tests of spherical plain bearings under differentoscillating frequencies, different coating compoundings and different pressures ofspray gun were considered by a high oscillating frequency and heavy load tribo-tester.The optimal compounding and the best spray gun pressure value will be found outthrough the test data processing and analysis.With the Scanning Electron Microscope and the Energy Disperse Spectroscopy, themicro morphologies and elements of the worn surface of spherical plain bearings wereanalyzed. The effects of different spray gun pressures and different coatingcompoundings on the wear mechanism of spherical plain bearings were discussed.Further find out the optimal compounding and the best spray gun pressure value. Theresults have a certain reference value to provide for the development of product qualityof spherical plain bearings.