Fatigue strength optimization design of crankshaft for turbocharged gasoline engine

LI Zhonghui, XIE Wei, LIU Hongrui

(Powertrain, Pan Asia Technical Automotive Center, Shanghai 201201, China)

Abstract: Aiming at improving the fatigue strength of the 1.4L naturally aspirated engine crankshaft to develop a 1.4L turbocharged engine crankshaft, the optimization design was carried out. In the material, higher strength forging steel was used to take the place of the nodular cast iron. In the process, the rolling force was increased from 6000N to 7000N. In the structure, the crankshaft balance weight was optimized, as a result 0.04kg lighter weight and higher fatigue strength were achieved. Based on the test standard GME L6C1, the fatigue tests were carried out to compare the fatigue strength of crankshafts. The research results indicate that the new crankshaft fatigue strength has been increased 24%, from 645N·m to 801N·m, which fully meets our target.

Key words: turbocharged gasoline engine; crankshaft; optimization design; fatigue strength