Sealing Performance Analysis Of Spring Energized Seal Ring

With the fast development of China's industry in the last few years,the high precision industry,aerospace,shipping,oil energy and other high-tech fields on the sealing requirements of industrial equipment are becoming more and more demanding,the seal leakage will reduce the use efficiency of equipment,the heavy damage to the structure itself and cause pollution to the environment.The energy storage spring seal ring combines the excellent friction and corrosion resistance characteristics of PTFE material and the high springback characteristics of the metal spring,so that it can be effectively sealed under either high pressure or low pressure.It is important to analyze the sealing characteristics of this kind of seal ring.The main work is concluded as follow :Taking liquid swivel with single point mooring system as an example,introduced the working principle of v-shaped spring energized ring,are used to characterize the peak contact pressure of static sealing performance,the physical parameters such as line contact pressure,Establishing a v-shaped energy storage spring simplified model of two-dimensional axisymmetric sealing ring,sealing ring is given of the contact type,boundary conditions and loading mode,etc.,to verify the metal spring energy storage to seal the compensation effect of contact,and analyzes the amount of compression,sealed jacket material elastic modulus and the sealing ring diameter influence on peak contact pressure,contact width,the conclusion is that the contact width of sealing lip decreases with the increase of material diameter and elastic modulus,and increases with the increase of interference.The peak contact pressure first increases and then decreases with the increase of the compression volume,and then increases with the increase of the elastic modulus of the material,which is proportional to the inner diameter.The range analysis of the orthogonal experimental results was carried out on the premise of satisfying the seal,and the main and secondary order of factors affecting the peak contact pressure of the seal ring were as follows: lip thickness,lip diameter,lip length,and pressure ring thickness;The main and secondary order of the factors affecting the linear contact pressure of the sealing ring: lip length,lip diameter,lip thickness,ring thickness.Finally,the main and secondary order of each factor was obtained by combining the two factors: lip thickness,lip diameter,lip length and compression ring thickness.The design of the seal ring should be fully considered the influence of structure parameters,interference quantities,jacket material properties on the sealing performance,high amount of interference when installation will cause the contact width has increased dramatically,acceleration on thesurface of the sealing ring wear,will reduce its service life,if you want to get higher when the design pressure distribution,can by increasing the amount of interference,the jacket material elastic modulus,priority change lip thick method;If you want to improve the service life of the seal ring,reduce the probability of friction and wear,while ensuring the seal can be achieved by reducing the interference,priority to change the seal ring lip size to achieve.Taking the sealing environment of the hydraulic cylinder as an example,the reciprocating sealing model of the v-shaped storage spring sealing ring was analyzed by finite element method.The stress-strain cloud diagram of the sealing ring under different pressure conditions(0-20mpa)was obtained.The results show that the parts of the seal ring which are easy to fail under high pressure include the contact part of the movable seal lip,the support part,the contact part between the back and the spring and the waist near the spring support part.The energy storage spring root and upper half of the waist,especially when the sealing pressure increased to 15 MPa,the maximum stress and strain area rapidly expanded,and the pressure value of the outer travel of the sealing jacket of this type of sealing ring is larger than that of the inner travel,more likely to fail.Simplified one-dimensional Reynolds equation is deduced,which is used to characterize the seal clearance fluid flow characteristics,reciprocating sealing fluid lubrication model is set up,will extract the seal lip contact pressure distribution as boundary conditions,using the method of reverse solution(IHL)get inside and outside travel film thickness in the process of dynamic seal,considering the effect of dynamic pressure on the gateway location of the oil film thickness updates,iterative calculation for pump seal return rate,fluid friction and compression rate of speed of pressure change.The results show that the seal ring of energy storage spring also has good sealing performance under low pressure condition,the axial moving speed(reciprocating speed)of piston rod increases,and the oil film thickness increases gradually.With the increase of speed,the pump return rate and friction force of the seal ring under different pressure conditions gradually increase.With the increase of precompression,the pump return rate and friction force of the seal ring increase.The influence of velocity change on friction and pump return rate is greater.The larger the elastic modulus of sealing jacket material,the smaller the contact width of the lip and the greater the maximum contact pressure.The smaller the fluid friction of instroke and outstroke travel,smaller the pump return rate.