曲轴承受交变脉动循环载荷,工作受力复杂,条件恶劣。因此,在曲轴设计中,为减少应力集中,提高曲轴的弯曲疲劳强度。在曲轴的轴颈过渡处采用适当的过渡圆角半径r的圆弧,使之应力集中系数控制在尽可能小的范围之内,保证曲轴安全工作。但在曲轴修磨时,往往由于磨削工人和检验人员对此未予充分重视,致使曲轴修磨后过渡圆角小于设计要求, Crankshaft bearings by alternating cycles of cyclic loading, work force complex, poor conditions. Therefore, in the crankshaft design, in order to reduce stress concentration, improve crankshaft bending fatigue strength. In the crankshaft journal transition at the appropriate transition fillet radius r arc, so that the stress concentration factor in the smallest possible range, to ensure the safety of the crankshaft work. However, when the crankshaft grinding, often due to grinding workers and inspectors have not paid sufficient attention to this, resulting in the transition fillet after grinding the crankshaft is less than the design requirements,