Research On Structure Optimization Of Friction Pair And Its End Seal Performance

As the proportion of mechanical seals used in petrochemical and aerospace fields gradually increased,higher requirements were placed on the performance of mechanical seals.As a key component of mechanical sealing equipment,friction pairs were directly related to the stability of industrial production.This research aimed at the seal failure of non-contact mechanical seals and contact mechanical seal friction pairs under high pressure and high speed conditions.Through numerical simulation and test methods,the leakage,opening force and thermal-structural coupling of the friction pair end face were measured.The resulting deformation was studied.(1)Established a numerical model of the spiral groove of the non-contact mechanical seal moving ring,used Fluent to simulate its pressure distribution law,analyze the spiral angle,the number of grooves,the depth of the groove,the thickness of the gas film,the speed,the inlet pressure and the peak pressure of the seal end face,the opening force,and the leakage The impact of the amount.The simulation results showed that the structural parameters of each spiral groove had a significant impact on its sealing performance.When the spiral angle is 15°and the number of grooves Ng=14,the leakage was the smallest and the dynamic pressure effect was good.The opening force and leakage increase gradually with the increase of groove depth,rotation speed,inlet pressure and other factors.The increase of gas film thickness causes the opening force to gradually decrease,while the leakage increased gradually.(2)Based on the analysis of the sealing performance of the traditional single helical corner groove,a structural parameter optimization analysis scheme of the double helical corner helical groove composed of suction surface β1 and pressure surface β2 was proposed.The study found that when the helix angle of the suction surface was greater than the helix angle of the pressure surface,the sealing effect was better.The double helix angle groove with a two-angle tolerance of 2° has smaller leakage than a double helix angle groove with a tolerance of 3°,and the performance was best when the two angles are matched at 19° and 17°.(3)Established the analysis model of the friction pair of the contact mechanical seal,apply thermal boundary and structural mechanics boundary conditions to the friction pair through Ansys Workbench software;apply the method of thermal-structure coupling to different speeds,medium pressure,material pairing,spring pressure,end face width The friction pair of the contact mechanical seal is analyzed for end face deformation.The results show that: the temperature of the friction pair and the overall deformation of the end face increase with the increase of the speed;the increase of the medium pressure will cause the uneven distribution of the end face specific pressure;by comparing the temperature of the friction pair under different material pairs,a pair can be selected to reduce the friction As the material for the secondary temperature rise,the dynamic ring material is resin-impregnated graphite,and the static ring material is tungsten carbide;appropriately reducing the spring pressure and increasing the end face width would reduce the end face temperature and overall deformation.(4)The temperature and end surface deformation of the friction pair under different working conditions were analyzed using the mechanical seal test bench for multifunctional pumps,and the friction coefficient and wear rate of the two groups of friction pairs under different sliding speeds,loads and temperatures were explored through friction and wear tests.The test results Similar to the results of the numerical simulation,the rationality of the numerical analysis method is verified.Through numerical simulation and test,the influence of structural parameters and operating parameters on the sealing performance was obtained,and the best structure which could effectively reduce the leakage of sealing face was selected.It provided a new research idea for the structure optimization and material selection of mechanical seal friction pair,and was conducive to further improving its sealing performance and engineering application.