Fatigue Life Test And Failure Behavior Analysis Of Bearing In Space Motor

Solid lubricant occupies an important position in the lubrication of space agencies.MoS2 sputtering coatings have widely application in space lubrication,due to itsexcellent properties such as low friction coefficient,resistance to radiation and high and low temperature in vacuum condition,current, The bearings, of which raceway surface is coated with sputtered MoS2 solid lubricant films and using a lubricating bearing cage, have been successfully applied to the mechanism of spacecraft. Because many factors can influence the life of solid lubricated bearings in space,bearing fatigue life theory is not perfect, through more ground simulation experiments to find the key factors that influence bearing life,Life range and Failure Mechanism is very important to improve the reliability of bearings.Taking into account bearing's installment and loading way in the stepper motor,analyzes the factors of space temperature cycling effects on the bearing`s load.based on ANSYS software,take the the relative displacement of the bearing` inside and outside ring caused by the motor`s thermal deformation as loading,influence of the high and low temperature on the bearing`s loading have been given by finite element method. To test the performance and life of bearings,the test-bed of bearing accelerated life test is designed and manufactured. The test-bed includes loading device,data acquisition system,speed and speed control system. Tests show that the test-bed is stable operation,can meet the intended function。A life simulation test is done in a vacuum test chamber for a different load and speed, test environment selected high and low temperature and room temperature in vacuum. A effective detection is done to bearing running state ,access to the bearing properties and lifetime data.Using modern analytical tools of SEM and XPS, Bearing lubrication failure of the test microstructure and elemental composition were tested.According to bearing wear area`s electron micrographs and energy spectrum,lubrication mechanism and wear mechanism of the bearing are analysied. Using experimental data measured in the bearing life, the parameters of the life model have been Calculated,bearing life estimate equation is given.