Comparative Studies of Connecting Rod Bearings Design on Capability to Discharge Foreign Particles

Foreign particles remaining in an engine cause bearing trouble on rare occasions. It is required to promptly and effectively discharge foreign particles from the bearing clearance space to improve reliability of the engine. In this paper, the bearing configuration of at the parting line between upper and lower bearings which are capable of discharging foreign particles are experimentally studied. Tests were conducted for fundamental visualization of oil flow and particles. As a result, the behavior of the particles in the bearing clearance space and the effects of the bearing configurations were well demonstrated. In the bench test using an actual engine, the bearing configuration with grooves at the parting line of the bearing demonstrated the effectiveness to prevent bearing damage caused by foreign particles. The influence of the bearing configurations on oil flow rate was confirmed not to increase the flow rate.