摘要
采用数理统计方法研究了不同板孔加工方法对滚子链链板疲劳强度的影响规律，给出了Ｒ－Ｓ－Ｎ曲线，且以铰孔试样为基准（光亮带１００％）得出表面质量系数的分布（μβ．σβ）。根据μβ．σβ更科学地评价了各种板孔加工方法的适用性，并进一步从板孔表面粗糙度、表面应力状态、疲劳裂纹萌生与扩展以及断口微观形貌等方面进行了理论分析。结果表明，链板疲劳裂纹萌生寿命占整个疲劳寿命的９０％以上，链板孔表面粗糙度、表面应力状态是影响链板疲劳强度的主要因素。与一次冲孔工艺相比，修孔工艺可使疲劳强度提高２８％，挤孔工艺可提高疲劳强度３８％。
Influence of different processing methods for plate hole on fatigue strength of roller chain plate is studied by mathematical statistics. R-S-N curve and distribution of surface quality coefficient (μβ.σβ) are given. The applicability of various processing methods is scientifically evaluated according to μβ and σβ. Theoretical analyses are made in light of surface roughness, surface stress, fatigue crack initiation and propagation and fractography. The result shows that, fatigue crack initiation life is above 90% of fatigue life. Surface roughness and stress state are the main influence factor of fatigue strength. Hole-dressing or hole-squeezing raises 28% and 38% of fatigue strength respectively..
基金
国家自然科学基金
关键词
滚子链
链板
疲劳强度
板孔加工法
roller chain
processing methods
fatigue strength
