柴油机曲轴疲劳强度影响因素研究分析

利用PRO/E建立了曲轴三维实体模型,采用ANSYS对曲轴疲劳强度的影响因素和应力分布进行了计算分析。讨论了曲柄臂厚度改变对结构强度的影响;主轴颈圆角半径和转速改变对最大正应力和剪应力的影响;不同连杆轴颈油孔结构对曲轴疲劳强度的影响。进行的疲劳强度试验验证结果表明：通过对轴颈圆角半径等局部结构参数的合理选择,可以提高曲轴可靠性。

The Study on the Influencing Factor for Fatigue Strength of Crankshaft in Diesel Engine

The influencing factors for fatigue strength of the crankshaft in a diesel engine and the stress distribution are calculated and analyzed on the solid model developed by Pro/E using software Ansys in this study. The effect of the crank thickness on the structure strength is discussed and the effect of the round radius of the shaft neck and the speed change on the maximum normal stress and the shearing strength are analyzed in detail as well.The analysis indicates that the structure of oil hole passing through the crankshaft also affects the strength.The test is conducted using 14 crankshafts with different materials,different structures and heat treatment.Based on results and calculations obtained from the test,the conclusion is drawn that crankshaft's reliability can be improved by material selection,heat treatment and reasonable placement of the oil hole under the condition of keeping its configuration unchanged.