DESIGN, ASSEMBLY AND PRELOADING OF BALL BEARINGS FOR SPACE APPLICATIONS – LESSONS LEARNED AND GUIDELINES FOR FUTURE SUCCESS

摘要

The use of ball bearings in the space industry is commonplace, with a broad range of applications from the most precise pointing mechanisms to extreme long -life and performance-demanding reaction wheels and simpler single-shot devices where precision, performance and life may be less difficult to achieve. Though most application developments are ultimately successful, the lessons learned from the incorrect implementation of ball bearings are, usually for understandable commercial reasons, not widely distributed – but often extremely valuable for industry. The organizations contributing to this paper have an unprecedentedly clear view of numerous spacecraft applications, both successful and otherwise, together with many years of experience in design, handling, lubricating, preloading and testing ball bearings for space applications. In order to help the space community to avoid design or handling errors in future, ESA has mandated bearing manufacturer ADR, and the European Space Tribology Laboratory (ESTL) to create a useful guideline which summarises both best practice and a distillation of the lessons learned from many programs. This paper presents a selection of the more valuable and generally applicable lessons learned by these organizations in the last 30-40 years together with an overview of the recently published guideline document itself [1] which embodies this experience and contains recommendations concerning ball bearing selection, design and conceptual rules and recommendations for assembly, preloading and verification testing. The novelty of this paper comes from the broad range of experiences and applications, both good and bad that the organisations concerned have observed and the publication (for the first time) of guidelines for use by the space mechanisms community in Europe.