Surface Lubrication Modification Research Of Bearing Cage

With the development of high-performance,long-life,high-reliability aerospace vehicles,aerospace bearings are often used in very harsh environments such as high temperature,high pressure,and high speed.The product life and reliability will directly affect the normal operation and flight safety of the aircraft.At present,with the continuous development of bearing materials,manufacturing processes and heat treatment technology,the fatigue life of bearings has been improved,but the acceleration of wear due to poor lubrication has become the main cause of bearing failure.In this paper,the effects of different process parameters,different linear velocities and different nominal contact stresses on friction and wear behavior are analyzed.The surface lubrication design parameters of aerospace bearing cage coatings are finally determined.The comparative test was used to analyze the test results of the appearance,microstructure,thickness,bonding force and surface roughness of the test piece.The effects of the most important process parameters in the silver plating and phosphating processes on the silver plating and the phosphating film were studied.And finally form optimal silver plating process and phosphating process.The friction and wear tests of silver plating,phosphating film and M50 steel ball under actual working conditions were simulated on the friction instrument.The effects of different process parameters,different nominal contact stresses and different linear velocities on the friction and wear behavior of silver coating and phosphating film were analyzed.Because of the friction and wear properties,the silver coating is far superior to the phosphating film.From the experimental results of friction coefficient,wear scar width and wear morphology,the silver plating formed by double pulse silver plating is superior to the silver formed by DC plating.Finally,the application of double-pulse silver plating on the bearing cage is verified.The performance of the double pulse silver plated cage was verified by using a tester to simulate the oil cut condition.Selecting a certain type of aviation bearing cage for double-pulse silver plating,which passed three 30 s oil-oil cut-off test,indicating that the double-pulse silver-plated cage plays a good lubrication role in the bearing oil-cutting process,and finally determines the double-pulse silver plating method,process equipment and main process parameters,and finally applied to the bearing cage engineering manufacturing.The silver plating formed by double pulse silver plating is superior to the silver formed by DC plating and phosphating.