三峡升船机齿轮齿条运行载荷与疲劳寿命研究

Operating Load and Fatigue Life of the Rack and Pinion of Three Gorges Ship Lift

通过三峡升船机实测运行数据分析,研究了升船机不同运行工况下的齿轮齿条载荷变化规律,并通过数据拟合结果建立齿轮齿条载荷计算模型。利用载荷模型与升船机不同行程内的船厢水深分布规律编制了多工况组合下的齿轮齿条载荷谱,通过齿轮齿条疲劳寿命计算,并结合前期的全尺寸模拟试验结果验证了三峡升船机齿轮齿条传动系统的服役可靠性。研究表明,三峡升船机齿轮齿条载荷主要由受船厢水深、运行状态控制的确定性载荷与一个服从正态分布的随机载荷偏差构成,通过数据拟合建立了升船机齿轮齿条载荷计算模型;受升船机运行模式与船厢水深变化影响,齿轮齿条上下齿面均会发生受载,且不同区域处齿条受载情况不一致,因此需要分区域编制载荷谱;对于驱动齿轮与中部齿条,载荷主要集中于齿轮下齿面与齿条上齿面,对于顶部和底部齿条,载荷分别集中于齿条的下齿面和上齿面,且其载荷较中部齿条更为显著;对于受载条件最为恶劣的底部齿条上齿面,计算得到滚动接触疲劳损伤损伤度仅达到1.36×10^(5),对应的齿条实际疲劳寿命可达到3.11×10^(11)次行程,远远超出齿条设计寿命;前期完成的全尺寸齿轮齿条模拟试验结果也同样验证了三峡升船机齿轮齿条传动系统在设计寿命周期内不存在疲劳损伤风险。

Based on the operating data of the Three Gorges ship lift,the variation load of the rack and pinion under different operating conditions is studied,and the load model is established using the data fitting results.The rack and pinion load spectrum under multiple working conditions was compiled via the load model and the statistical distribution of water depth in the operations of ship lift.The service reliability of the rack and pinion transmission system of Three Gorges ship lift was verified by the fatigue life calculation in the combination with previous full-size test results.The results show that the operating load of rack and pinion of the Three Gorges ship lift is mainly composed of a deterministic load that controlled by the water depth and operating state and a random load deviation conforming to the normal distribution.The load model is established based on the data fitting results.Under the influence of the ship lift operation state and the water depth of the ship box,the load could be at both the upper and lower tooth surfaces of the rack and pinion,and the magnitude of load at different positions of the rack is not the same,so it is necessary to compile the load spectrum by region and component the rack and pinion.The load is mainly concentrated on the pinion’s lower tooth surface and the upper tooth surface of the rack in the middle region,but for the rack in the top and bottom region,the loaded surface is mainly the lower and upper tooth surface,respectively,and the load is more significant than that of the middle rack.It is the upper tooth surface of the bottom rack that suffered the most severe load condition,while its calculated fatigue damage degree is only 1.36×10^(5),corresponding to a potential fatigue life of 3.11×10^(11) cycles,which is far beyond the design life of the rack.The full-size simulation test results completed in an early stage also verified that there is no risk of fatigue damage of the pinion and rack of the Three Gorges ship lift.