Abstract:

In order to investigate the contact mechanics and the friction as well as wear mechanism of small-module gears in a spacecraft in vacuum environment,a mathematical model to describ the contact stress loading on the gear meshing interface was established,and the stress distribution was analyzed. Then,a vacuum friction-and-wear experimental platform of the gear system was set up,and the main friction and wear behaviours of a gear in vacuum and atmorsphere are comparatively investigated. Finally,according to the micromorphology of wear scar at defferent locations on the meshing surface,the relationship between the contact stress distribution in the gearing interface and the friction and wear behaviours of the gear is analyzed. The results show that the occurrence of adhesive wear in vacuum environment is more easier than that in atmospheric condition,that the contact stress distribution closely relates to the adhesive wear,that the contact stress value has a decisive effect on the adhesion of gear,and that the
wear form of the space gear in vacuum environment is mainly adhesive wear,while that in atmorspheric conditon is fatigue wear combining with abrasive wear.

Key words: spacecraft, small-module gear, friction, wear, contact stress, experimental investigation