Design And Experimental Study Of High Pressure Mechanical Seal

Mechanical seal,as an important part of rotating machinery,can prevent medium in mechanical equipment from leaking from between rotating shafts,and it is a kind of dynamic sealing device.In some harsh working conditions(such as the seabed),the service life of mechanical seals needs to cover the whole design life of the equipment,and it is not easy to replace and maintain during use because of the limited conditions.Therefore,the mechanical seal design needs to meet the sealing requirements on the premise of ensuring the service life to meet the requirements.Aiming at this goal,this paper designs the sealing structure of high-pressure resistant mechanical seal,and puts forward a controllable and adjustable design scheme.Specifically,when the spring elasticity of mechanical seal is insufficient and the seal ring is severely worn,which leads to seal failure,it can actively supplement the insufficient end face specific pressure and continuously ensure the sealing performance.aiming at the designed mechanical seal,a high-pressure test rig is built and experimental research is carried out.This paper has carried out experimental research,mainly including the following contents:(1)design and build a mechanical seal test bed.Can be used for experimental research on mechanical seal sealing performance under different pressures and different rotating speeds.The spring specific pressure is changed by changing the screwing progress of the bolt,and then the end face specific pressure of the sealing end face is changed,so as to verify the feasibility of controllable mechanical seal which takes the end face specific pressure as a feedback signal to change the screwing progress of the spring.(2)by means of the test rig,the wear properties of friction pairs composed of four materials yt5 tungsten steel,zirconia,silicon carbide and carbon graphite were tested,and the relationship between the wear amount and friction coefficient of four materials and the rotational speed and end load was obtained.The hardness of four kinds of materials was tested,and the mechanism of end face friction loss was further discussed by combining with microscopic mechanism.The PV value is used to quantitatively reflect the wear of the end face,and finally the mechanism of the seal ring's hard-soft collocation is summarized.(3)combining theoretical analysis and test results,the influence of spring specific pressure and radial taper on mechanical seal performance in balanced mechanical seal is studied,which lays a theoretical foundation for designing controllable mechanical seal structure with end specific pressure as feedback signal and adjustable spring specific pressure.