Design Of Accelerated Life Rig For Reciprocating Seals

Reciprocating seals have a wide range of applications in industrial production,especially in the automotive,aerospace,and medical fields.The failure of reciprocating seals often directly affects the performance of the sealing system,and then affects the reliability and stability of the hydraulic system.In some cases,it can cause huge property losses and serious safety accidents.Therefore,it is of great significance to carry out research on reciprocating seals.In recent years,the demands for the high-quality economic development in our country and the acceleration of the strategic transformation of the manufacturing industry have placed new requirements on the safety and production quality of industrial production.Reciprocating seal is an important component in a wide range of applications in hydraulic systems.Its failure will seriously reduce the sealing performance of the hydraulic system and reduce the reliability and safety of the system.Therefore,its performance and reliability must be continuously improved.In the actual working conditions of reciprocating seals,as the number of reciprocating movements increases,the sealing performance will gradually decrease.Many factors such as friction,environmental media,and operating temperature will affect the performance of the reciprocating seal.However,wear is one of the most important factors.According to relevant data,among the failure types of seals,problems caused by wear in the types of seal failures are up to 75% or more.The wear process of the reciprocating seal is extremely complicated,and it is difficult to accurately identify it only by simulation technology,and it must be verified by experiments.In this thesis,a new type of hydraulic reciprocating seal accelerated life test rig is developed based on engineering practice to explore the dynamic changes of friction in the reciprocating seal,and it provides a platform for the accelerated life test and reliability analysis of the reciprocating seal.The main contributions of this thesis are:(1)A mechanical design scheme of the accelerated life test rig for reciprocating seals is developed.After reviewing the existing studies on the reciprocating seal test rig,the advantages and disadvantages of the existing reciprocating seal test rig are identified.A new design of reciprocating seal test rig is proposed by incorporating the requirements of the accelerated life test of the hydraulic reciprocating seal and the principles of friction force measurement.Additionally,the design schemes of some components of the test rig,such as hydraulic cylinder block,are introduced.Finally,the hydraulic station device used in the test rig is illustrated.(2)The design optimization of the reciprocating seal structure is conducted.According to the design scheme of the reciprocating seal test rig,by simplifying the boundary conditions,a two-dimensional finite element simulation model of the reciprocating seal structure is constructed to study the factors which affect the sealing performance.By combining with the finite element simulation results,ANSYS and opti SLang software are used to analyze the influencing factors of the reciprocating seal performance,and then realize the optimal design of the reciprocating seal structure,and improve the design of the test rig based on the optimized design results.(3)The control system of the reciprocating seal test rig is developed.LabVIEW graphical programming language is used to design the motion control system and data acquisition system,and provide the optional scheme of the relevant equipment.Meanwhile,due to the customized requirements of different reliability tests for motor speed and stroke,Kollmorgen Work Bench is used to design the control function of the servo motor spindle.The designed control interfaces of the test rig,such as the login interface,the main interface,and the data acquisition interface,are presented.Finally,the installation scheme of the test rig is formulated based on the design scheme of the test rig and the ground rules of electrical equipment.(4)The reliability evaluation method of reciprocating seal based on friction pair theory is proposed.For the metal/polymer friction pair system of the seal ring,the friction pair theory is employed to analyze the reliability of the reciprocating seal.Through the two-dimensional distribution function of the ultimate stress,the reliability evaluation method of the friction pair system is derived.The value selection method of the related parameters is illustrated by combining the material properties and movement characteristics of the reciprocating seal.