Research On Temperature?Deformation And Wear Performance Of High-speed Dry Friction Mechanical Seals

Dry friction mechanical seals run at high speed without lubrication.The combined effect of spring pressure and cavity pressure causes the friction to generate heat faster and the temperature of the seal face is higher,which can easily cause deformation of the seal face and affect the overall performance of the seal.This study aimed at the problems of unstable performance and seal failure caused by deformation of high-speed dry friction seals in practical applications.The temperature field of the seal,the deformation of the seal face and its friction and wear performance were studied by numerical simulation and test methods.First,a finite element model of the dry friction mechanical seal was established.Steady-state temperature field is simulated after simplifying the rotating ring,static ring and the rotating shaft into a central axis symmetry model.The effect of operating parameters,performance parameters,structural parameters,and seal ring materials on temperature field was discussed.The results show that the temperature of the seal ring increases with the increase of the speed,the specific pressure of the end face and the pressure of the spring,and decreased with the increase of the cavity pressure,the medium flow rate,the thickness and end width of static ring.By comparing the temperature of the different material pairs of the seal ring under different working conditions,the material of the rotating ring which has the least temperature rise of the seal ring was 38CrMoAlA,and the material of the static ring is M106K.On the basis of the numerical analysis model of the temperature field,the analysis model of the thermal-mechanical coupling deformation is established.Based on the model,the thermal deformation,the mechanical deformation and the thermal-mechanical coupling deformation of the seal end face were analyzed separately.Three types of deformation and the difference between moving and static ring deformation were compared.The influence of cavity pressure,rotation speed and static ring end face width on the thermal coupling deformation were discussed.The analysis results show that the force deformation is the smallest during the three deformations,and the thermal-mechanical coupling deformation is not a simple superposition of the thermal and force deformation.The static ring deformation is significantly larger than the rotating ring.Properly reducing the rotation speed and cavity pressure can reduce the deformation of the sealing end face.When the cavity pressure is 0.2-0.3MPa,the end face deformation is minimum when the width of the static ring end face is 2.4mm?2.7mm.By comparing the seal ring deformation of different seal ring material pairs,the material pair with the smallest deformation was selected as 38CrMoAlA and M106K.The multi-functional friction and wear test machine was used to analyze the friction coefficient of different sealing material pairs under dry friction conditions.The self-developed dry friction mechanical seal test bench was used to analyze the seal ring temperature and end surface deformation under different working conditions.And then the morphology of the end faces of the paired sealing materials was analyzed.It is confirmed that the test results are in good agreement with the numerical calculation results,which verifies the temperature and deformation performanceof the high-speed dry friction seal and the rationality and reliability of numerical analysis.Through the numerical simulation analysis and experimental investigation of the temperature field and deformation of the high-speed dry friction mechanical seal,the temperature and deformation law of the seal end surface are revealed.The optimal structure,operating parameters and sealing material pairs that can reduce the temperature rise and deformation of the seal end surface can provide new research ideas for the structural optimization,material selection and end surface deformation control of high-speed dry friction mechanical seals,which is conducive to further improve the performance of such seals and promote their engineering applications.