Development of a Needle Roller Bearing for the Large-End of a 2-Cycle Engine Connecting Rod

The running conditions of the connecting rod bearings for two-cycle engines have been made more critical recently than they were before, even after the rolling bearings, especially, the needle roller bearings were introduced for them. The bearing performance has to meet the running conditions reliably, which are even less lubrication, high temperature and high speed.

This paper discusses the characteristics of the needle roller bearings based on the bearing test results, and two-cycle engine firing test results from a bearing manufacture's viewpoint, and also the development of the connecting rod large-end bearings to improve rotation speed and anti-seizure.