Study of the Motion of Floating Piston Pin against Pin Bore

One of the major problems that the automotive industry faces is reducing friction to increase efficiency. Researchers have shown that 30% of the fuel energy was consumed to overcome the friction forces between the moving parts of any automobile, Holmberg et al. [1]. The interface of the piston pin and pin bore is one of the areas that generate high friction under severe working conditions of high temperature and lack of lubrication. In this research, experimental investigation and theoretical simulation have been carried out to analyze the motion of the floating pin against pin bore. In the experimental study, the focus was on analyzing the floating pin motion by using a bench test rig to simulate the floating pin motion in an internal combustion engine. A motion data acquisition system was developed to capture and record the pin motion. Thousands of images were recorded and later analyzed by a code written by MATLAB. In the simulation, friction and lubrication analysis for reciprocating engine (FLARE) tools were adopted to carry out an elastohydrodynamic (EHD) lubrication analysis of the piston pin/bore interface and simulate the pin motion. The results showed that the motion of the floating pin was significantly affected by applied load and lubrication conditions. The experimental and theoretical results match very well.