Study On The Mechanism And Performance Of A New Magnetic Mechanical Seal

In order to solve the problem of magnetic attenuation of magnetic-mechanical oil seal ring and the instability of sealing,a new type of magnetic mechanical seal is proposed.Through the analysis of the principle of the structure,a mathematical model of the new structure of magnetic mechanical seal in the electromagnetic field and end surface flow field is established.According to the basic theory of Reynolds equation,the finite difference method is used to evaluate the mathematical formulas and parameters.MATLAB and ANSYS software are used to formulate the calculation of the formula and the model's electromagnetic field simulation,the relationship between the magnetic field and the sealing performance change and the variation law of the model in the magnetic field are obtained.Through the analysis of the results,the excellent performance of the new magnetic mechanical seal is revealed,and the two problems of the magnetic oil seal are solved.It provides a theoretical reference for the future application of magnetic mechanical seals.And results are as follows:1)It can be concluded by solving the magnetic field performance parameters,As the current increases,the magnetic induction,electromagnetic force,and balance force increase.2)When the film thickness changes within a small gap of h0<3um,the increase of the film thickness makes the magnitude of magnetic induction,electromagnetic force,and balance force drastically decrease.In the case of film thickness h0>3um,the magnetic induction,electromagnetic force,and balance force tend to change slowly;3)Through the solution of the end surface fluid performance parameters,it can be seen that as the gap thickness of the end surface increases,the leakage amount increases,and the opening force,stiffness and rigid-to-leakage ratio gradually decrease;When the end gap is between h0=1~3um,the leakage amount shows a sharp increase,and the opening force,stiffness and rigid-to-drain ratio all show a sharp decline.Moreover,the leakage amount can reach less than 0.2m3/h,and the fluid stiffness performance has also been improved,resulting in better sealing performance of the end face.Based on the above analysis,it can be seen that the electromagnetic force at both ends of the moving ring is adjusted,and the thickness of the fluid film at the sealing end surface is maintained within the range of h0=1-3 um.At this time,the mechanical seal obtains a stable and good working state.4)In the analysis of the static magnetic field model,it can be seen that when a current of 0.2A~0.8A is applied to the coil,the magnetic mechanical seal can obtain uniform distribution of the magnetic flux density cloud distribution and the electromagnetic force distribution map.The sealing member can saturate and magnetize the stationary ring by charging the coils at both ends,thereby solving the degaussing problem of the stationary ring;the control of the sealing end surface is controlled due to the controllable electromagnetic force,so that the stable working condition of end surface sealing is obtained.