Investigation of Creeping Interference Between Hole and Shaft in Precision Assembly Process

Abstract The hole and shaft interference press-fit technology provides unique connection performance and has become essential in aerospace and military assembly applications. Traditional manufacturing methods necessitate high bonding strength; however, achieving precise press fit positioning is equally critical. Implementing a slow pressing technique to ensure high accuracy may lead to a phenomenon known as “crawling,” which in turn increases positional errors. A dynamic analysis of the system elucidates the general motion characteristics associated with crawling. Experimental results indicate that increased interference reduces the noncontact area due to the plastic deformation of surface micro-convex bodies, thereby mitigating crawling. Furthermore, this research investigates the effects of surface roughness, interference levels, and nominal diameter on interference fit creep, identifying significant influencing factors and mechanisms. It is concluded that reducing the crossing resistance of micro-convex bodies is a crucial approach for enhancing interference fit accuracy.