离心泵轴承疲劳寿命仿真分析及试验验证

Simulation analysis and experimental verification on bearings fatigue life of a centrifugal pump

针对工程中常出现的离心泵轴承实际寿命低于其设计寿命问题,以IS 100-80-160型离心泵为研究对象,对其进行数值仿真,将多个工况下的仿真结果与工程中校核泵轴承寿命的Steponff经验公式进行对比,发现Steponff公式计算出的径向力值偏小.为分析Steponff公式计算的轴承寿命校核误差,将径向力加载至轴承内圈进行有限元疲劳寿命仿真分析,并搭建离心泵径向力及轴承寿命试验台进行试验验证.结果表明:径向力计算误差以及工况变化将产生较大的轴承寿命偏差,该偏差在额定工况下最大,且随着径向力变大而逐步减小;与ISO寿命计算结果对比,数值仿真疲劳寿命安全系数更高;Steponff公式的计算值不够准确,将导致轴承实际寿命与其设计寿命相差极大;在大型低比转数离心泵轴承选用中,需考量Steponff公式的适用范围,同时可应用数值仿真校核其额定寿命.研究结果可为大型泵轴承寿命校核提供一定的依据.

In response to the issue where a centrifugal pump′s actual bearing life falled lower than its design life in engineering,an IS 100-80-160 centrifugal pump was taken as the research subject,and the numerical simulation was performed.The simulation results under multiple working conditions were compared with the empirical Steponff formula for calibrating the pump′s bearing life in nuclear pumps in engineering,and it was discovered that the radial force value calculated by the Steponff formula was relative small.To analyze the calculated bearing life verification error,the radial force was loaded onto the inner ring of the bearing for finite element fatigue life simulation analysis.It is discovered that both the radial force calculation error and the variation under operating conditions will result in significant bearing life deviation.This deviation is maximum under rated operating conditions and gradually decreases as radial force increases.The safety factor is determined to be higher when comparing the computed results of ISO life with the simulated fatigue life.Ultimately,the centrifugal pump test bench for radial force and bearing life demonstrates that the Steponff formula′s calculation value is not precise enough,which will result in a significant difference between the bearing′s real life and its design life.Therefore,the application range of the Steponff formula must be taken into account when choosing large low specific speed centrifugal pump bearings.At the same time,numerical simulation can be used to verify the rated life of the pump bearing,which has some engineering significance for the large pump bearings′current life check.