| Momentum wheel is a key equipment of gesture control system in spacecraft, as miniature precision angle contact ball bearing to momentum wheel. The performances and life of spacecraft lie on the performances of bearing such as precision, vibration, the waviness of friction torque and life. Such kinds of bearings often operate with high speed and light load in space environment. The common failure mode is wear-out occurring under insufficient lubrication condition, as a result, the vibration, noise and friction moment increased and revolving precision decreased. Nowadays, the wear life calculation of rolling bearing is got by experiment data that obtained more than twenty years ago. So, developing a new calculation method is imperative.In this paper, a certain momentum wheel bearing is analyzed with quasi-static method. some performances such as the stress distributing between balls and raceways, slipping velocity distributing, lubrication parameter, etc, can be obtained, and a calculate model of wear lifetime of momentum wheel bearing based on Archard's wear theory is established. Then a piece of software is developed. And how the working conditions and structural parameters affect the life of bearings is also studied with the software. Lastly, verify the rationality of bearing's wear life with experiment, and the reliability of momentum wheel bearing is evaluated with Bayes—Weibull estimations method.The theoretical analysis and the experimental result show that the wear life of the bearings can be indicated by the variation of preload. The wear rate of inner raceway is about 13 times that of outer raceway. The wear rate of bearings is increased with the preload, but there is an optimization value. The wear rate of bearings is increased with the rotational speed of outer ring, the wear life decreased with it too, but in low speed it decreased fast than high speed. The wear rate of bearings is increased with the coefficients of inner raceway groove curvature radius, 0.52 is an optimization value to the wear life. The wear rate and wear life of bearings is increased with the coefficients of outer raceway groove curvature radius. |
