Interference and thickness design of bushing of connecting rod small end for Anti-loosening

A bushing is usually assembled with the small end of a connecting rod in an engine by an interference fit. Inappropriate interference or insufficient stiffness of the small end will cause loosening of bushing. Since the bushing loosening often occurred in the development process of the studied V-type diesel engine, the pressing force applied to push the bushing out of the small end was used to evaluate the tightness of the connection between the bushing and the small end. In this paper, the influence of bushing thickness and interference on the pressing force of the bushing of the connecting rod small end in the V-type diesel engine was investigated by finite element method. Considering the strength of the bushing and the stiffness of the connecting rod small end, the suitable bushing thickness and interference for this connecting rod small end were obtained and verified in practice.