基于加速退化试验的机械密封磨损寿命预测

Mechanical Seal Wear Lifetime Prediction Based on Accelerated Degradation Test

针对目前机械密封应用领域高可靠性的要求,提出了基于随机过程的可靠性分析及磨损寿命预测方法。以密封端面磨损量为研究对象,设计适用于机械密封的加速退化试验以获得磨损退化数据。基于退化模型Gamma过程描述其磨损退化过程,引入双应力逆幂率模型作为加速模型描述转速、弹簧力与退化速率间的关系,从而建立机械密封可靠性分析与寿命预测模型。通过极大似然估计法求解模型参数,结合加速模型外推出多个应力水平下的模型参数并进行失效概率分析,对机械密封在不同可靠度需求下的可靠寿命及不同工作条件下的平均寿命作出了预测。结果表明,Gamma过程适用于描述机械密封的磨损退化过程,通过双应力逆幂率模型外推获得各应力水平下的可靠度及寿命,此方法比传统的机械密封寿命预测方法具有更好的实用性和灵活性,可为密封产品确定维修周期及保证安全运行提供重要参考。

Aiming at the current high-reliability requirements of mechanical seal application,a reliability analysis and wear lifetime prediction method based on stochastic process are proposed.Taking the wear of seal face as the research object,the accelerated degradation test for mechanical seal is designed to obtain wear degradation data.The Gamma process is used as the degradation model to describe the mechanical seal wear degradation pro⁃cess.The double stress inverse power rate model is introduced as the acceleration model to describe the relation⁃ship between rotational speed,spring force and the degradation rate.The mechanical seal reliability analysis and life prediction model is established,and the model parameters is solved by the maximum likelihood estimation method,combining the acceleration model to introduce the model parameters under multiple stress levels and an⁃alyze the failure probability.The reliable life expectancy under different reliability requirements and the average life expectancy under different working conditions have been predicted.The results show that the Gamma pro⁃cess is suitable for describing the wear degradation process of mechanical seals.The reliability and life of each stress level can be obtained by extrapolation of the double stress inverse power rate model,which has better practicability and flexibility than the traditional mechanical seal life prediction method,providing an important reference for determining the maintenance cycle and ensuring safe operation of sealing products.