Life Test Verification of Oil-Lubricated Bearing for Space Scanning Motor

This study is to verify whether the design life of the oil-lubricated bearing for the infrared earth sensor scanning motor meets the requirements of the 5-year life expectancy. Firstly, theoretical calculation was conducted to determine the initial oil quantity of the oil-lubricated bearing for requirement of the running life of the motor. Secondly, the reliability of the oil lubrication method was verified by an 1:1 scanning motor ground life test. After the life test, the rolling bearing was observed microscopically, and the bearing was analyzed. During the life test of the scanning motor, the operation was normal, the motor current was stable at 20~40 mA, and the cumulative running time of the scanning motor was more than 8 years. The results of bearing microscopic analysis showed that the inner and outer ring raceways and balls had good surface condition, and the surface roughness of the moving inner surface of the bearing inner ring changed from 0.416 μm to 0.512 μm. There is no obvious pitting and wear, and the lubrication was in good condition. The life test results of the scanning motor verify that oil-containing cage with oil reservoir can meet the 5-year life requirement of the motor bearing. Test results provided reference for other long-life design of the space rotating component in the boundary lubrication regime.