Development And Performance Test Of Double Row Roller Bearing With External Spherical Surface For High Temperature Environment

With the rapid development of China’s aviation industry and space flight technology,the performance requirements of all kinds of space vehicles are increasing.As an important mechanical part of the aircraft,people pay more and more attention to the scientific research on how to improve its service performance.The bearings in space vehicles are often in high temperature,heavy load and other harsh conditions.At the same time,the running state of the bearings will directly affect the overall performance of the aircraft,so the development of high service performance and high reliability bearings is particularly important.China’s aviation bearing technology started late,and the gap between China and other countries is obvious.Therefore,the development of highperformance aviation bearing development system is of great significance to the development of China’s aviation and aerospace industry.This paper focuses on the research and development of double row roller bearing in high temperature environment,and carries out systematic work such as basic design,theoretical analysis,physical manufacturing and test of bearing.First of all,the bearing structure design,material selection and lubrication design are carried out according to the task requirements.Then the carrying capacity of the bearing is analyzed.The influence of the bearing structure parameters and solid film parameters on the carrying capacity is analyzed,and the bearing structure improvement and film selection scheme are determined.Then,the finite element software is used to analyze the contact state of a whole bearing,between a single roller and raceway,and between a single roller and a coated raceway.The contact stress level of the bearing is obtained,and the simulation results are compared with the Hertzian calculation results.The friction moment calculation model of solid lubrication bearing is established,and the influence of radial load,friction coefficient and radial clearance on the friction moment of bearing is analyzed.A batch of quantitative roller surface coating tooling is designed and processed.The coating process is analyzed and the coating scheme is determined.And multi arc ion plating technology is used to complete the preparation of modified coating on the working surface of bearings.After that,the surface morphology,thickness,hardness,modulus of elasticity and other mechanical properties of the film are tested and analyzed by means of microscope,SEM,indentation instrument and other equipments.The scratch critical load of Cr N-M50 film-substrate system is analyzed and calculated.The threedimensional finite element model of ball disk friction is established to analyze the influence of friction coefficient,elastic modulus and film thickness on the stress distribution of the film-substrate system,so as to verify the rationality of the lubrication design.The performance tests of high-temperature bearing in various natural and mechanical environments are carried out.And it is verified that this bearing can maintain the stability of the structure under various environmental tests through the inspection work of the bearing after the tests.Use the high-temperature test bench,design the test tooling,develop the test plan,and test the service performance of solid lubricated bearing under high temperature and heavy load conditions.Finally,the actual friction torque of the tested bearing is obtained.The experimental results show that the bearing can meet the requirements of ultimate load and service life.At the same time,the effectiveness of solid lubrication scheme is proved.