등속조인트용 그리스 마찰특성 연구

A GAF (generated axial force) is produced at a plunging-type CVJ (constant velocity joint). A high GAF can cause vibrations in a vehicle. Grease is used to reduce friction between the roller and the track of the outer case of a CVJ. The grease performance depends on the surface conditions and operating temperature. The surface of the outer case is extremely rough and hard. In recent times, the maximum operating temperature of CVJs has crossed 140oC, because the exhaust line is now located close to the CVJ. In this study, we examined the friction characteristics of friction additives at 25-150oC and determined an optimal formulation with a low friction coefficient. This formulation can be used to develop low-friction grease that can reduce the GAF produced at a CVJ by approximately 7-26%.