Research On Reliability Of Nuclear Main Pump Vertical Thrust Sliding Bearing

In the nuclear power system,the nuclear main pump bearing is a key equipment that needs to assume all the axial loads produced in the system.Its bearing capacity directly affects the load capacity of the main pump and is one of the decisive factors for the reliable and stable operation of the nuclear main pump.With the development of industry,the requirements for mechanical products are not only required to meet the requirements of performance,but also make higher requirements for its reliability.Especially for nuclear power and industrial products,the requirements of reliability will be very strict,but the independent production of the bearing of the nuclear main pump is still in the development stage in China,lacking corresponding bearing usage data and fault data.Therefore,our country lacks a reliability evaluation system that is suitable for practical application of engineering.The main research content of this paper is to propose a method for evaluating the reliability of sliding bearings in the practical application of engineering,and to establish a reliability system for similar products in the future to better solve bearing reliability engineering problems.The main contents of this paper are as follows:(1)Through two fault analysis modes,FMEA and fault tree,the severity of each part was determined,and the thrust watts,guide bushes and elastic discs were identified as key parts.According to the difference of the failure mode and the cause of the failure,the fault tree of the "burning tile" of the nuclear main pump bearing is compiled,which has a profound guiding value and reference significance for the regular maintenance and design of the main pump bearing of the main pump.Finally,how to form a perfect reliability data system is proposed to provide data and complete reliability design requirements for the reliability archives of the nuclear main pump bearing,as well as to provide the direction for improving the reliability management of the product,and to lay the foundation for further improving the reliability of the bearing of the nuclear main pump.(2)The three-dimensional proportional model of the nuclear main pump bearing is established by using SolidWorks software,and the reliability model of the bearing is established according to the failure mode analysis.The reliability index is assigned to each unit by the scoring method,and the Ansys software is used to solve the stress range of each unit.The reliability of each unit is obtained by Monte Carlo sampling,and compares with the distribution value.The reliability of the thrust tile and cooler must be tested and verified by experiment.(3)Through the calculation to find the weak link of bearing reliability and design the test scheme for reliability verification of axle bush starting and stopping wear,the accelerated test method is determined on the basis of Stree Beck curve,the test times are determined by the dispersion coefficient method,and the reliability requirements can be achieved by the weak link in turn,and a special test bench is set up to verify the reliability of the key parts.For oil-water coolers,special test benches are built to ensure the cooling effect through long-term operation and inspection of the heat transfer effect.